xref: /openbmc/linux/fs/nfsd/nfs4xdr.c (revision 3b73c45e)
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 #include <linux/sunrpc/addr.h>
44 #include <linux/xattr.h>
45 #include <uapi/linux/xattr.h>
46 
47 #include "idmap.h"
48 #include "acl.h"
49 #include "xdr4.h"
50 #include "vfs.h"
51 #include "state.h"
52 #include "cache.h"
53 #include "netns.h"
54 #include "pnfs.h"
55 #include "filecache.h"
56 
57 #include "trace.h"
58 
59 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
60 #include <linux/security.h>
61 #endif
62 
63 
64 #define NFSDDBG_FACILITY		NFSDDBG_XDR
65 
66 const u32 nfsd_suppattrs[3][3] = {
67 	{NFSD4_SUPPORTED_ATTRS_WORD0,
68 	 NFSD4_SUPPORTED_ATTRS_WORD1,
69 	 NFSD4_SUPPORTED_ATTRS_WORD2},
70 
71 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
72 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
73 	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
74 
75 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
76 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
77 	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
78 };
79 
80 /*
81  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
82  * directory in order to indicate to the client that a filesystem boundary is present
83  * We use a fixed fsid for a referral
84  */
85 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
86 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
87 
88 static __be32
89 check_filename(char *str, int len)
90 {
91 	int i;
92 
93 	if (len == 0)
94 		return nfserr_inval;
95 	if (len > NFS4_MAXNAMLEN)
96 		return nfserr_nametoolong;
97 	if (isdotent(str, len))
98 		return nfserr_badname;
99 	for (i = 0; i < len; i++)
100 		if (str[i] == '/')
101 			return nfserr_badname;
102 	return 0;
103 }
104 
105 static int zero_clientid(clientid_t *clid)
106 {
107 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
108 }
109 
110 /**
111  * svcxdr_tmpalloc - allocate memory to be freed after compound processing
112  * @argp: NFSv4 compound argument structure
113  * @len: length of buffer to allocate
114  *
115  * Allocates a buffer of size @len to be freed when processing the compound
116  * operation described in @argp finishes.
117  */
118 static void *
119 svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
120 {
121 	struct svcxdr_tmpbuf *tb;
122 
123 	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
124 	if (!tb)
125 		return NULL;
126 	tb->next = argp->to_free;
127 	argp->to_free = tb;
128 	return tb->buf;
129 }
130 
131 /*
132  * For xdr strings that need to be passed to other kernel api's
133  * as null-terminated strings.
134  *
135  * Note null-terminating in place usually isn't safe since the
136  * buffer might end on a page boundary.
137  */
138 static char *
139 svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
140 {
141 	char *p = svcxdr_tmpalloc(argp, len + 1);
142 
143 	if (!p)
144 		return NULL;
145 	memcpy(p, buf, len);
146 	p[len] = '\0';
147 	return p;
148 }
149 
150 static void *
151 svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, u32 len)
152 {
153 	__be32 *tmp;
154 
155 	/*
156 	 * The location of the decoded data item is stable,
157 	 * so @p is OK to use. This is the common case.
158 	 */
159 	if (p != argp->xdr->scratch.iov_base)
160 		return p;
161 
162 	tmp = svcxdr_tmpalloc(argp, len);
163 	if (!tmp)
164 		return NULL;
165 	memcpy(tmp, p, len);
166 	return tmp;
167 }
168 
169 /*
170  * NFSv4 basic data type decoders
171  */
172 
173 /*
174  * This helper handles variable-length opaques which belong to protocol
175  * elements that this implementation does not support.
176  */
177 static __be32
178 nfsd4_decode_ignored_string(struct nfsd4_compoundargs *argp, u32 maxlen)
179 {
180 	u32 len;
181 
182 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
183 		return nfserr_bad_xdr;
184 	if (maxlen && len > maxlen)
185 		return nfserr_bad_xdr;
186 	if (!xdr_inline_decode(argp->xdr, len))
187 		return nfserr_bad_xdr;
188 
189 	return nfs_ok;
190 }
191 
192 static __be32
193 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
194 {
195 	__be32 *p;
196 	u32 len;
197 
198 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
199 		return nfserr_bad_xdr;
200 	if (len == 0 || len > NFS4_OPAQUE_LIMIT)
201 		return nfserr_bad_xdr;
202 	p = xdr_inline_decode(argp->xdr, len);
203 	if (!p)
204 		return nfserr_bad_xdr;
205 	o->data = svcxdr_savemem(argp, p, len);
206 	if (!o->data)
207 		return nfserr_jukebox;
208 	o->len = len;
209 
210 	return nfs_ok;
211 }
212 
213 static __be32
214 nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
215 {
216 	__be32 *p, status;
217 
218 	if (xdr_stream_decode_u32(argp->xdr, lenp) < 0)
219 		return nfserr_bad_xdr;
220 	p = xdr_inline_decode(argp->xdr, *lenp);
221 	if (!p)
222 		return nfserr_bad_xdr;
223 	status = check_filename((char *)p, *lenp);
224 	if (status)
225 		return status;
226 	*namp = svcxdr_savemem(argp, p, *lenp);
227 	if (!*namp)
228 		return nfserr_jukebox;
229 
230 	return nfs_ok;
231 }
232 
233 static __be32
234 nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
235 {
236 	__be32 *p;
237 
238 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
239 	if (!p)
240 		return nfserr_bad_xdr;
241 	p = xdr_decode_hyper(p, &tv->tv_sec);
242 	tv->tv_nsec = be32_to_cpup(p++);
243 	if (tv->tv_nsec >= (u32)1000000000)
244 		return nfserr_inval;
245 	return nfs_ok;
246 }
247 
248 static __be32
249 nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
250 {
251 	__be32 *p;
252 
253 	p = xdr_inline_decode(argp->xdr, NFS4_VERIFIER_SIZE);
254 	if (!p)
255 		return nfserr_bad_xdr;
256 	memcpy(verf->data, p, sizeof(verf->data));
257 	return nfs_ok;
258 }
259 
260 /**
261  * nfsd4_decode_bitmap4 - Decode an NFSv4 bitmap4
262  * @argp: NFSv4 compound argument structure
263  * @bmval: pointer to an array of u32's to decode into
264  * @bmlen: size of the @bmval array
265  *
266  * The server needs to return nfs_ok rather than nfserr_bad_xdr when
267  * encountering bitmaps containing bits it does not recognize. This
268  * includes bits in bitmap words past WORDn, where WORDn is the last
269  * bitmap WORD the implementation currently supports. Thus we are
270  * careful here to simply ignore bits in bitmap words that this
271  * implementation has yet to support explicitly.
272  *
273  * Return values:
274  *   %nfs_ok: @bmval populated successfully
275  *   %nfserr_bad_xdr: the encoded bitmap was invalid
276  */
277 static __be32
278 nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
279 {
280 	ssize_t status;
281 
282 	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
283 	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
284 }
285 
286 static __be32
287 nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
288 {
289 	__be32 *p, status;
290 	u32 length;
291 
292 	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
293 		return nfserr_bad_xdr;
294 	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
295 		return nfserr_bad_xdr;
296 	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
297 		return nfserr_bad_xdr;
298 
299 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
300 		return nfserr_bad_xdr;
301 	p = xdr_inline_decode(argp->xdr, length);
302 	if (!p)
303 		return nfserr_bad_xdr;
304 	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
305 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
306 		status = nfs_ok;
307 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
308 		status = nfsd_map_name_to_gid(argp->rqstp,
309 				(char *)p, length, &ace->who_gid);
310 	else
311 		status = nfsd_map_name_to_uid(argp->rqstp,
312 				(char *)p, length, &ace->who_uid);
313 
314 	return status;
315 }
316 
317 /* A counted array of nfsace4's */
318 static noinline __be32
319 nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
320 {
321 	struct nfs4_ace *ace;
322 	__be32 status;
323 	u32 count;
324 
325 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
326 		return nfserr_bad_xdr;
327 
328 	if (count > xdr_stream_remaining(argp->xdr) / 20)
329 		/*
330 		 * Even with 4-byte names there wouldn't be
331 		 * space for that many aces; something fishy is
332 		 * going on:
333 		 */
334 		return nfserr_fbig;
335 
336 	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
337 	if (*acl == NULL)
338 		return nfserr_jukebox;
339 
340 	(*acl)->naces = count;
341 	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
342 		status = nfsd4_decode_nfsace4(argp, ace);
343 		if (status)
344 			return status;
345 	}
346 
347 	return nfs_ok;
348 }
349 
350 static noinline __be32
351 nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
352 			    struct xdr_netobj *label)
353 {
354 	u32 lfs, pi, length;
355 	__be32 *p;
356 
357 	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
358 		return nfserr_bad_xdr;
359 	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
360 		return nfserr_bad_xdr;
361 
362 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
363 		return nfserr_bad_xdr;
364 	if (length > NFS4_MAXLABELLEN)
365 		return nfserr_badlabel;
366 	p = xdr_inline_decode(argp->xdr, length);
367 	if (!p)
368 		return nfserr_bad_xdr;
369 	label->len = length;
370 	label->data = svcxdr_dupstr(argp, p, length);
371 	if (!label->data)
372 		return nfserr_jukebox;
373 
374 	return nfs_ok;
375 }
376 
377 static __be32
378 nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
379 		    struct iattr *iattr, struct nfs4_acl **acl,
380 		    struct xdr_netobj *label, int *umask)
381 {
382 	unsigned int starting_pos;
383 	u32 attrlist4_count;
384 	__be32 *p, status;
385 
386 	iattr->ia_valid = 0;
387 	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
388 	if (status)
389 		return nfserr_bad_xdr;
390 
391 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
392 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
393 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
394 		if (nfsd_attrs_supported(argp->minorversion, bmval))
395 			return nfserr_inval;
396 		return nfserr_attrnotsupp;
397 	}
398 
399 	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
400 		return nfserr_bad_xdr;
401 	starting_pos = xdr_stream_pos(argp->xdr);
402 
403 	if (bmval[0] & FATTR4_WORD0_SIZE) {
404 		u64 size;
405 
406 		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
407 			return nfserr_bad_xdr;
408 		iattr->ia_size = size;
409 		iattr->ia_valid |= ATTR_SIZE;
410 	}
411 	if (bmval[0] & FATTR4_WORD0_ACL) {
412 		status = nfsd4_decode_acl(argp, acl);
413 		if (status)
414 			return status;
415 	} else
416 		*acl = NULL;
417 	if (bmval[1] & FATTR4_WORD1_MODE) {
418 		u32 mode;
419 
420 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
421 			return nfserr_bad_xdr;
422 		iattr->ia_mode = mode;
423 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
424 		iattr->ia_valid |= ATTR_MODE;
425 	}
426 	if (bmval[1] & FATTR4_WORD1_OWNER) {
427 		u32 length;
428 
429 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
430 			return nfserr_bad_xdr;
431 		p = xdr_inline_decode(argp->xdr, length);
432 		if (!p)
433 			return nfserr_bad_xdr;
434 		status = nfsd_map_name_to_uid(argp->rqstp, (char *)p, length,
435 					      &iattr->ia_uid);
436 		if (status)
437 			return status;
438 		iattr->ia_valid |= ATTR_UID;
439 	}
440 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
441 		u32 length;
442 
443 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
444 			return nfserr_bad_xdr;
445 		p = xdr_inline_decode(argp->xdr, length);
446 		if (!p)
447 			return nfserr_bad_xdr;
448 		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
449 					      &iattr->ia_gid);
450 		if (status)
451 			return status;
452 		iattr->ia_valid |= ATTR_GID;
453 	}
454 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
455 		u32 set_it;
456 
457 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
458 			return nfserr_bad_xdr;
459 		switch (set_it) {
460 		case NFS4_SET_TO_CLIENT_TIME:
461 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
462 			if (status)
463 				return status;
464 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
465 			break;
466 		case NFS4_SET_TO_SERVER_TIME:
467 			iattr->ia_valid |= ATTR_ATIME;
468 			break;
469 		default:
470 			return nfserr_bad_xdr;
471 		}
472 	}
473 	if (bmval[1] & FATTR4_WORD1_TIME_CREATE) {
474 		struct timespec64 ts;
475 
476 		/* No Linux filesystem supports setting this attribute. */
477 		bmval[1] &= ~FATTR4_WORD1_TIME_CREATE;
478 		status = nfsd4_decode_nfstime4(argp, &ts);
479 		if (status)
480 			return status;
481 	}
482 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
483 		u32 set_it;
484 
485 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
486 			return nfserr_bad_xdr;
487 		switch (set_it) {
488 		case NFS4_SET_TO_CLIENT_TIME:
489 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
490 			if (status)
491 				return status;
492 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
493 			break;
494 		case NFS4_SET_TO_SERVER_TIME:
495 			iattr->ia_valid |= ATTR_MTIME;
496 			break;
497 		default:
498 			return nfserr_bad_xdr;
499 		}
500 	}
501 	label->len = 0;
502 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
503 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
504 		status = nfsd4_decode_security_label(argp, label);
505 		if (status)
506 			return status;
507 	}
508 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
509 		u32 mode, mask;
510 
511 		if (!umask)
512 			return nfserr_bad_xdr;
513 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
514 			return nfserr_bad_xdr;
515 		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
516 		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
517 			return nfserr_bad_xdr;
518 		*umask = mask & S_IRWXUGO;
519 		iattr->ia_valid |= ATTR_MODE;
520 	}
521 
522 	/* request sanity: did attrlist4 contain the expected number of words? */
523 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
524 		return nfserr_bad_xdr;
525 
526 	return nfs_ok;
527 }
528 
529 static __be32
530 nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
531 {
532 	__be32 *p;
533 
534 	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
535 	if (!p)
536 		return nfserr_bad_xdr;
537 	sid->si_generation = be32_to_cpup(p++);
538 	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
539 	return nfs_ok;
540 }
541 
542 static __be32
543 nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
544 {
545 	__be32 *p;
546 
547 	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
548 	if (!p)
549 		return nfserr_bad_xdr;
550 	memcpy(clientid, p, sizeof(*clientid));
551 	return nfs_ok;
552 }
553 
554 static __be32
555 nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
556 			  clientid_t *clientid, struct xdr_netobj *owner)
557 {
558 	__be32 status;
559 
560 	status = nfsd4_decode_clientid4(argp, clientid);
561 	if (status)
562 		return status;
563 	return nfsd4_decode_opaque(argp, owner);
564 }
565 
566 #ifdef CONFIG_NFSD_PNFS
567 static __be32
568 nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
569 		       struct nfsd4_deviceid *devid)
570 {
571 	__be32 *p;
572 
573 	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
574 	if (!p)
575 		return nfserr_bad_xdr;
576 	memcpy(devid, p, sizeof(*devid));
577 	return nfs_ok;
578 }
579 
580 static __be32
581 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
582 			   struct nfsd4_layoutcommit *lcp)
583 {
584 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
585 		return nfserr_bad_xdr;
586 	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
587 		return nfserr_bad_xdr;
588 	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
589 		return nfserr_bad_xdr;
590 
591 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
592 		return nfserr_bad_xdr;
593 	if (lcp->lc_up_len > 0) {
594 		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
595 		if (!lcp->lc_up_layout)
596 			return nfserr_bad_xdr;
597 	}
598 
599 	return nfs_ok;
600 }
601 
602 static __be32
603 nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
604 			   struct nfsd4_layoutreturn *lrp)
605 {
606 	__be32 status;
607 
608 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
609 		return nfserr_bad_xdr;
610 	switch (lrp->lr_return_type) {
611 	case RETURN_FILE:
612 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
613 			return nfserr_bad_xdr;
614 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
615 			return nfserr_bad_xdr;
616 		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
617 		if (status)
618 			return status;
619 		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
620 			return nfserr_bad_xdr;
621 		if (lrp->lrf_body_len > 0) {
622 			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
623 			if (!lrp->lrf_body)
624 				return nfserr_bad_xdr;
625 		}
626 		break;
627 	case RETURN_FSID:
628 	case RETURN_ALL:
629 		lrp->lr_seg.offset = 0;
630 		lrp->lr_seg.length = NFS4_MAX_UINT64;
631 		break;
632 	default:
633 		return nfserr_bad_xdr;
634 	}
635 
636 	return nfs_ok;
637 }
638 
639 #endif /* CONFIG_NFSD_PNFS */
640 
641 static __be32
642 nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
643 			struct nfs4_sessionid *sessionid)
644 {
645 	__be32 *p;
646 
647 	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
648 	if (!p)
649 		return nfserr_bad_xdr;
650 	memcpy(sessionid->data, p, sizeof(sessionid->data));
651 	return nfs_ok;
652 }
653 
654 /* Defined in Appendix A of RFC 5531 */
655 static __be32
656 nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
657 			   struct nfsd4_cb_sec *cbs)
658 {
659 	u32 stamp, gidcount, uid, gid;
660 	__be32 *p, status;
661 
662 	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
663 		return nfserr_bad_xdr;
664 	/* machine name */
665 	status = nfsd4_decode_ignored_string(argp, 255);
666 	if (status)
667 		return status;
668 	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
669 		return nfserr_bad_xdr;
670 	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
671 		return nfserr_bad_xdr;
672 	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
673 		return nfserr_bad_xdr;
674 	if (gidcount > 16)
675 		return nfserr_bad_xdr;
676 	p = xdr_inline_decode(argp->xdr, gidcount << 2);
677 	if (!p)
678 		return nfserr_bad_xdr;
679 	if (cbs->flavor == (u32)(-1)) {
680 		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
681 
682 		kuid_t kuid = make_kuid(userns, uid);
683 		kgid_t kgid = make_kgid(userns, gid);
684 		if (uid_valid(kuid) && gid_valid(kgid)) {
685 			cbs->uid = kuid;
686 			cbs->gid = kgid;
687 			cbs->flavor = RPC_AUTH_UNIX;
688 		} else {
689 			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
690 		}
691 	}
692 
693 	return nfs_ok;
694 }
695 
696 static __be32
697 nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
698 			     struct nfsd4_cb_sec *cbs)
699 {
700 	__be32 status;
701 	u32 service;
702 
703 	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
704 
705 	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
706 		return nfserr_bad_xdr;
707 	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
708 		return nfserr_bad_xdr;
709 	/* gcbp_handle_from_server */
710 	status = nfsd4_decode_ignored_string(argp, 0);
711 	if (status)
712 		return status;
713 	/* gcbp_handle_from_client */
714 	status = nfsd4_decode_ignored_string(argp, 0);
715 	if (status)
716 		return status;
717 
718 	return nfs_ok;
719 }
720 
721 /* a counted array of callback_sec_parms4 items */
722 static __be32
723 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
724 {
725 	u32 i, secflavor, nr_secflavs;
726 	__be32 status;
727 
728 	/* callback_sec_params4 */
729 	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
730 		return nfserr_bad_xdr;
731 	if (nr_secflavs)
732 		cbs->flavor = (u32)(-1);
733 	else
734 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
735 		cbs->flavor = 0;
736 
737 	for (i = 0; i < nr_secflavs; ++i) {
738 		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
739 			return nfserr_bad_xdr;
740 		switch (secflavor) {
741 		case RPC_AUTH_NULL:
742 			/* void */
743 			if (cbs->flavor == (u32)(-1))
744 				cbs->flavor = RPC_AUTH_NULL;
745 			break;
746 		case RPC_AUTH_UNIX:
747 			status = nfsd4_decode_authsys_parms(argp, cbs);
748 			if (status)
749 				return status;
750 			break;
751 		case RPC_AUTH_GSS:
752 			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
753 			if (status)
754 				return status;
755 			break;
756 		default:
757 			return nfserr_inval;
758 		}
759 	}
760 
761 	return nfs_ok;
762 }
763 
764 
765 /*
766  * NFSv4 operation argument decoders
767  */
768 
769 static __be32
770 nfsd4_decode_access(struct nfsd4_compoundargs *argp,
771 		    struct nfsd4_access *access)
772 {
773 	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
774 		return nfserr_bad_xdr;
775 	return nfs_ok;
776 }
777 
778 static __be32
779 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
780 {
781 	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
782 		return nfserr_bad_xdr;
783 	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
784 }
785 
786 
787 static __be32
788 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
789 {
790 	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
791 		return nfserr_bad_xdr;
792 	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
793 		return nfserr_bad_xdr;
794 	return nfs_ok;
795 }
796 
797 static __be32
798 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
799 {
800 	__be32 *p, status;
801 
802 	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
803 		return nfserr_bad_xdr;
804 	switch (create->cr_type) {
805 	case NF4LNK:
806 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
807 			return nfserr_bad_xdr;
808 		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
809 		if (!p)
810 			return nfserr_bad_xdr;
811 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
812 		if (!create->cr_data)
813 			return nfserr_jukebox;
814 		break;
815 	case NF4BLK:
816 	case NF4CHR:
817 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
818 			return nfserr_bad_xdr;
819 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
820 			return nfserr_bad_xdr;
821 		break;
822 	case NF4SOCK:
823 	case NF4FIFO:
824 	case NF4DIR:
825 	default:
826 		break;
827 	}
828 	status = nfsd4_decode_component4(argp, &create->cr_name,
829 					 &create->cr_namelen);
830 	if (status)
831 		return status;
832 	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
833 				    ARRAY_SIZE(create->cr_bmval),
834 				    &create->cr_iattr, &create->cr_acl,
835 				    &create->cr_label, &create->cr_umask);
836 	if (status)
837 		return status;
838 
839 	return nfs_ok;
840 }
841 
842 static inline __be32
843 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
844 {
845 	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
846 }
847 
848 static inline __be32
849 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
850 {
851 	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
852 				    ARRAY_SIZE(getattr->ga_bmval));
853 }
854 
855 static __be32
856 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
857 {
858 	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
859 }
860 
861 static __be32
862 nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
863 				 struct nfsd4_lock *lock)
864 {
865 	__be32 status;
866 
867 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
868 		return nfserr_bad_xdr;
869 	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
870 	if (status)
871 		return status;
872 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
873 		return nfserr_bad_xdr;
874 	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
875 					 &lock->lk_new_owner);
876 }
877 
878 static __be32
879 nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
880 			       struct nfsd4_lock *lock)
881 {
882 	__be32 status;
883 
884 	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
885 	if (status)
886 		return status;
887 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
888 		return nfserr_bad_xdr;
889 
890 	return nfs_ok;
891 }
892 
893 static __be32
894 nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
895 {
896 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
897 		return nfserr_bad_xdr;
898 	if (lock->lk_is_new)
899 		return nfsd4_decode_open_to_lock_owner4(argp, lock);
900 	return nfsd4_decode_exist_lock_owner4(argp, lock);
901 }
902 
903 static __be32
904 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
905 {
906 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
907 		return nfserr_bad_xdr;
908 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
909 		return nfserr_bad_xdr;
910 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
911 		return nfserr_bad_xdr;
912 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
913 		return nfserr_bad_xdr;
914 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
915 		return nfserr_bad_xdr;
916 	return nfsd4_decode_locker4(argp, lock);
917 }
918 
919 static __be32
920 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
921 {
922 	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
923 		return nfserr_bad_xdr;
924 	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
925 		return nfserr_bad_xdr;
926 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
927 		return nfserr_bad_xdr;
928 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
929 		return nfserr_bad_xdr;
930 	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
931 					 &lockt->lt_owner);
932 }
933 
934 static __be32
935 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
936 {
937 	__be32 status;
938 
939 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
940 		return nfserr_bad_xdr;
941 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
942 		return nfserr_bad_xdr;
943 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
944 		return nfserr_bad_xdr;
945 	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
946 	if (status)
947 		return status;
948 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
949 		return nfserr_bad_xdr;
950 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
951 		return nfserr_bad_xdr;
952 
953 	return nfs_ok;
954 }
955 
956 static __be32
957 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
958 {
959 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
960 }
961 
962 static __be32
963 nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
964 {
965 	__be32 status;
966 
967 	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
968 		return nfserr_bad_xdr;
969 	switch (open->op_createmode) {
970 	case NFS4_CREATE_UNCHECKED:
971 	case NFS4_CREATE_GUARDED:
972 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
973 					     ARRAY_SIZE(open->op_bmval),
974 					     &open->op_iattr, &open->op_acl,
975 					     &open->op_label, &open->op_umask);
976 		if (status)
977 			return status;
978 		break;
979 	case NFS4_CREATE_EXCLUSIVE:
980 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
981 		if (status)
982 			return status;
983 		break;
984 	case NFS4_CREATE_EXCLUSIVE4_1:
985 		if (argp->minorversion < 1)
986 			return nfserr_bad_xdr;
987 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
988 		if (status)
989 			return status;
990 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
991 					     ARRAY_SIZE(open->op_bmval),
992 					     &open->op_iattr, &open->op_acl,
993 					     &open->op_label, &open->op_umask);
994 		if (status)
995 			return status;
996 		break;
997 	default:
998 		return nfserr_bad_xdr;
999 	}
1000 
1001 	return nfs_ok;
1002 }
1003 
1004 static __be32
1005 nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1006 {
1007 	__be32 status;
1008 
1009 	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
1010 		return nfserr_bad_xdr;
1011 	switch (open->op_create) {
1012 	case NFS4_OPEN_NOCREATE:
1013 		break;
1014 	case NFS4_OPEN_CREATE:
1015 		status = nfsd4_decode_createhow4(argp, open);
1016 		if (status)
1017 			return status;
1018 		break;
1019 	default:
1020 		return nfserr_bad_xdr;
1021 	}
1022 
1023 	return nfs_ok;
1024 }
1025 
1026 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
1027 {
1028 	u32 w;
1029 
1030 	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
1031 		return nfserr_bad_xdr;
1032 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
1033 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
1034 	if (deleg_when)
1035 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
1036 
1037 	switch (w & NFS4_SHARE_ACCESS_MASK) {
1038 	case NFS4_SHARE_ACCESS_READ:
1039 	case NFS4_SHARE_ACCESS_WRITE:
1040 	case NFS4_SHARE_ACCESS_BOTH:
1041 		break;
1042 	default:
1043 		return nfserr_bad_xdr;
1044 	}
1045 	w &= ~NFS4_SHARE_ACCESS_MASK;
1046 	if (!w)
1047 		return nfs_ok;
1048 	if (!argp->minorversion)
1049 		return nfserr_bad_xdr;
1050 	switch (w & NFS4_SHARE_WANT_MASK) {
1051 	case NFS4_SHARE_WANT_NO_PREFERENCE:
1052 	case NFS4_SHARE_WANT_READ_DELEG:
1053 	case NFS4_SHARE_WANT_WRITE_DELEG:
1054 	case NFS4_SHARE_WANT_ANY_DELEG:
1055 	case NFS4_SHARE_WANT_NO_DELEG:
1056 	case NFS4_SHARE_WANT_CANCEL:
1057 		break;
1058 	default:
1059 		return nfserr_bad_xdr;
1060 	}
1061 	w &= ~NFS4_SHARE_WANT_MASK;
1062 	if (!w)
1063 		return nfs_ok;
1064 
1065 	if (!deleg_when)	/* open_downgrade */
1066 		return nfserr_inval;
1067 	switch (w) {
1068 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
1069 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
1070 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
1071 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
1072 		return nfs_ok;
1073 	}
1074 	return nfserr_bad_xdr;
1075 }
1076 
1077 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
1078 {
1079 	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
1080 		return nfserr_bad_xdr;
1081 	/* Note: unlike access bits, deny bits may be zero. */
1082 	if (*x & ~NFS4_SHARE_DENY_BOTH)
1083 		return nfserr_bad_xdr;
1084 
1085 	return nfs_ok;
1086 }
1087 
1088 static __be32
1089 nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
1090 			 struct nfsd4_open *open)
1091 {
1092 	__be32 status;
1093 
1094 	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
1095 		return nfserr_bad_xdr;
1096 	switch (open->op_claim_type) {
1097 	case NFS4_OPEN_CLAIM_NULL:
1098 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
1099 		status = nfsd4_decode_component4(argp, &open->op_fname,
1100 						 &open->op_fnamelen);
1101 		if (status)
1102 			return status;
1103 		break;
1104 	case NFS4_OPEN_CLAIM_PREVIOUS:
1105 		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
1106 			return nfserr_bad_xdr;
1107 		break;
1108 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
1109 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1110 		if (status)
1111 			return status;
1112 		status = nfsd4_decode_component4(argp, &open->op_fname,
1113 						 &open->op_fnamelen);
1114 		if (status)
1115 			return status;
1116 		break;
1117 	case NFS4_OPEN_CLAIM_FH:
1118 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1119 		if (argp->minorversion < 1)
1120 			return nfserr_bad_xdr;
1121 		/* void */
1122 		break;
1123 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1124 		if (argp->minorversion < 1)
1125 			return nfserr_bad_xdr;
1126 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1127 		if (status)
1128 			return status;
1129 		break;
1130 	default:
1131 		return nfserr_bad_xdr;
1132 	}
1133 
1134 	return nfs_ok;
1135 }
1136 
1137 static __be32
1138 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1139 {
1140 	__be32 status;
1141 	u32 dummy;
1142 
1143 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
1144 	open->op_iattr.ia_valid = 0;
1145 	open->op_openowner = NULL;
1146 
1147 	open->op_xdr_error = 0;
1148 	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
1149 		return nfserr_bad_xdr;
1150 	/* deleg_want is ignored */
1151 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
1152 					   &open->op_deleg_want, &dummy);
1153 	if (status)
1154 		return status;
1155 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
1156 	if (status)
1157 		return status;
1158 	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
1159 					   &open->op_owner);
1160 	if (status)
1161 		return status;
1162 	status = nfsd4_decode_openflag4(argp, open);
1163 	if (status)
1164 		return status;
1165 	return nfsd4_decode_open_claim4(argp, open);
1166 }
1167 
1168 static __be32
1169 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
1170 {
1171 	__be32 status;
1172 
1173 	if (argp->minorversion >= 1)
1174 		return nfserr_notsupp;
1175 
1176 	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
1177 	if (status)
1178 		return status;
1179 	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
1180 		return nfserr_bad_xdr;
1181 
1182 	return nfs_ok;
1183 }
1184 
1185 static __be32
1186 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
1187 {
1188 	__be32 status;
1189 
1190 	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
1191 	if (status)
1192 		return status;
1193 	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
1194 		return nfserr_bad_xdr;
1195 	/* deleg_want is ignored */
1196 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1197 					   &open_down->od_deleg_want, NULL);
1198 	if (status)
1199 		return status;
1200 	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1201 }
1202 
1203 static __be32
1204 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
1205 {
1206 	__be32 *p;
1207 
1208 	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
1209 		return nfserr_bad_xdr;
1210 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1211 		return nfserr_bad_xdr;
1212 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
1213 	if (!p)
1214 		return nfserr_bad_xdr;
1215 	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
1216 	if (!putfh->pf_fhval)
1217 		return nfserr_jukebox;
1218 
1219 	return nfs_ok;
1220 }
1221 
1222 static __be32
1223 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
1224 {
1225 	if (argp->minorversion == 0)
1226 		return nfs_ok;
1227 	return nfserr_notsupp;
1228 }
1229 
1230 static __be32
1231 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
1232 {
1233 	__be32 status;
1234 
1235 	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
1236 	if (status)
1237 		return status;
1238 	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
1239 		return nfserr_bad_xdr;
1240 	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
1241 		return nfserr_bad_xdr;
1242 
1243 	return nfs_ok;
1244 }
1245 
1246 static __be32
1247 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
1248 {
1249 	__be32 status;
1250 
1251 	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
1252 		return nfserr_bad_xdr;
1253 	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
1254 	if (status)
1255 		return status;
1256 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
1257 		return nfserr_bad_xdr;
1258 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
1259 		return nfserr_bad_xdr;
1260 	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
1261 					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
1262 		return nfserr_bad_xdr;
1263 
1264 	return nfs_ok;
1265 }
1266 
1267 static __be32
1268 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
1269 {
1270 	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
1271 }
1272 
1273 static __be32
1274 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
1275 {
1276 	__be32 status;
1277 
1278 	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
1279 	if (status)
1280 		return status;
1281 	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
1282 }
1283 
1284 static __be32
1285 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
1286 {
1287 	return nfsd4_decode_clientid4(argp, clientid);
1288 }
1289 
1290 static __be32
1291 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1292 		     struct nfsd4_secinfo *secinfo)
1293 {
1294 	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
1295 }
1296 
1297 static __be32
1298 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
1299 {
1300 	__be32 status;
1301 
1302 	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
1303 	if (status)
1304 		return status;
1305 	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
1306 				   ARRAY_SIZE(setattr->sa_bmval),
1307 				   &setattr->sa_iattr, &setattr->sa_acl,
1308 				   &setattr->sa_label, NULL);
1309 }
1310 
1311 static __be32
1312 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
1313 {
1314 	__be32 *p, status;
1315 
1316 	if (argp->minorversion >= 1)
1317 		return nfserr_notsupp;
1318 
1319 	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
1320 	if (status)
1321 		return status;
1322 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1323 	if (status)
1324 		return status;
1325 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
1326 		return nfserr_bad_xdr;
1327 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
1328 		return nfserr_bad_xdr;
1329 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
1330 	if (!p)
1331 		return nfserr_bad_xdr;
1332 	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
1333 						setclientid->se_callback_netid_len);
1334 	if (!setclientid->se_callback_netid_val)
1335 		return nfserr_jukebox;
1336 
1337 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
1338 		return nfserr_bad_xdr;
1339 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
1340 	if (!p)
1341 		return nfserr_bad_xdr;
1342 	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
1343 						setclientid->se_callback_addr_len);
1344 	if (!setclientid->se_callback_addr_val)
1345 		return nfserr_jukebox;
1346 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
1347 		return nfserr_bad_xdr;
1348 
1349 	return nfs_ok;
1350 }
1351 
1352 static __be32
1353 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1354 {
1355 	__be32 status;
1356 
1357 	if (argp->minorversion >= 1)
1358 		return nfserr_notsupp;
1359 
1360 	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
1361 	if (status)
1362 		return status;
1363 	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
1364 }
1365 
1366 /* Also used for NVERIFY */
1367 static __be32
1368 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1369 {
1370 	__be32 *p, status;
1371 
1372 	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
1373 				      ARRAY_SIZE(verify->ve_bmval));
1374 	if (status)
1375 		return status;
1376 
1377 	/* For convenience's sake, we compare raw xdr'd attributes in
1378 	 * nfsd4_proc_verify */
1379 
1380 	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
1381 		return nfserr_bad_xdr;
1382 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
1383 	if (!p)
1384 		return nfserr_bad_xdr;
1385 	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
1386 	if (!verify->ve_attrval)
1387 		return nfserr_jukebox;
1388 
1389 	return nfs_ok;
1390 }
1391 
1392 static __be32
1393 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1394 {
1395 	__be32 status;
1396 
1397 	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
1398 	if (status)
1399 		return status;
1400 	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
1401 		return nfserr_bad_xdr;
1402 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
1403 		return nfserr_bad_xdr;
1404 	if (write->wr_stable_how > NFS_FILE_SYNC)
1405 		return nfserr_bad_xdr;
1406 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
1407 		return nfserr_bad_xdr;
1408 	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
1409 		return nfserr_bad_xdr;
1410 
1411 	return nfs_ok;
1412 }
1413 
1414 static __be32
1415 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1416 {
1417 	__be32 status;
1418 
1419 	if (argp->minorversion >= 1)
1420 		return nfserr_notsupp;
1421 
1422 	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
1423 					   &rlockowner->rl_owner);
1424 	if (status)
1425 		return status;
1426 
1427 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1428 		return nfserr_inval;
1429 
1430 	return nfs_ok;
1431 }
1432 
1433 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
1434 {
1435 	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
1436 		return nfserr_bad_xdr;
1437 	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
1438 }
1439 
1440 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
1441 {
1442 	u32 use_conn_in_rdma_mode;
1443 	__be32 status;
1444 
1445 	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
1446 	if (status)
1447 		return status;
1448 	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
1449 		return nfserr_bad_xdr;
1450 	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
1451 		return nfserr_bad_xdr;
1452 
1453 	return nfs_ok;
1454 }
1455 
1456 static __be32
1457 nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
1458 			       struct nfsd4_exchange_id *exid)
1459 {
1460 	__be32 status;
1461 
1462 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
1463 				      ARRAY_SIZE(exid->spo_must_enforce));
1464 	if (status)
1465 		return nfserr_bad_xdr;
1466 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
1467 				      ARRAY_SIZE(exid->spo_must_allow));
1468 	if (status)
1469 		return nfserr_bad_xdr;
1470 
1471 	return nfs_ok;
1472 }
1473 
1474 /*
1475  * This implementation currently does not support SP4_SSV.
1476  * This decoder simply skips over these arguments.
1477  */
1478 static noinline __be32
1479 nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
1480 			  struct nfsd4_exchange_id *exid)
1481 {
1482 	u32 count, window, num_gss_handles;
1483 	__be32 status;
1484 
1485 	/* ssp_ops */
1486 	status = nfsd4_decode_state_protect_ops(argp, exid);
1487 	if (status)
1488 		return status;
1489 
1490 	/* ssp_hash_algs<> */
1491 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1492 		return nfserr_bad_xdr;
1493 	while (count--) {
1494 		status = nfsd4_decode_ignored_string(argp, 0);
1495 		if (status)
1496 			return status;
1497 	}
1498 
1499 	/* ssp_encr_algs<> */
1500 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1501 		return nfserr_bad_xdr;
1502 	while (count--) {
1503 		status = nfsd4_decode_ignored_string(argp, 0);
1504 		if (status)
1505 			return status;
1506 	}
1507 
1508 	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
1509 		return nfserr_bad_xdr;
1510 	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
1511 		return nfserr_bad_xdr;
1512 
1513 	return nfs_ok;
1514 }
1515 
1516 static __be32
1517 nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
1518 			      struct nfsd4_exchange_id *exid)
1519 {
1520 	__be32 status;
1521 
1522 	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
1523 		return nfserr_bad_xdr;
1524 	switch (exid->spa_how) {
1525 	case SP4_NONE:
1526 		break;
1527 	case SP4_MACH_CRED:
1528 		status = nfsd4_decode_state_protect_ops(argp, exid);
1529 		if (status)
1530 			return status;
1531 		break;
1532 	case SP4_SSV:
1533 		status = nfsd4_decode_ssv_sp_parms(argp, exid);
1534 		if (status)
1535 			return status;
1536 		break;
1537 	default:
1538 		return nfserr_bad_xdr;
1539 	}
1540 
1541 	return nfs_ok;
1542 }
1543 
1544 static __be32
1545 nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
1546 			  struct nfsd4_exchange_id *exid)
1547 {
1548 	__be32 status;
1549 	u32 count;
1550 
1551 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1552 		return nfserr_bad_xdr;
1553 	switch (count) {
1554 	case 0:
1555 		break;
1556 	case 1:
1557 		/* Note that RFC 8881 places no length limit on
1558 		 * nii_domain, but this implementation permits no
1559 		 * more than NFS4_OPAQUE_LIMIT bytes */
1560 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1561 		if (status)
1562 			return status;
1563 		/* Note that RFC 8881 places no length limit on
1564 		 * nii_name, but this implementation permits no
1565 		 * more than NFS4_OPAQUE_LIMIT bytes */
1566 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1567 		if (status)
1568 			return status;
1569 		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
1570 		if (status)
1571 			return status;
1572 		break;
1573 	default:
1574 		return nfserr_bad_xdr;
1575 	}
1576 
1577 	return nfs_ok;
1578 }
1579 
1580 static __be32
1581 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1582 			 struct nfsd4_exchange_id *exid)
1583 {
1584 	__be32 status;
1585 
1586 	status = nfsd4_decode_verifier4(argp, &exid->verifier);
1587 	if (status)
1588 		return status;
1589 	status = nfsd4_decode_opaque(argp, &exid->clname);
1590 	if (status)
1591 		return status;
1592 	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
1593 		return nfserr_bad_xdr;
1594 	status = nfsd4_decode_state_protect4_a(argp, exid);
1595 	if (status)
1596 		return status;
1597 	return nfsd4_decode_nfs_impl_id4(argp, exid);
1598 }
1599 
1600 static __be32
1601 nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
1602 			    struct nfsd4_channel_attrs *ca)
1603 {
1604 	__be32 *p;
1605 
1606 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
1607 	if (!p)
1608 		return nfserr_bad_xdr;
1609 
1610 	/* headerpadsz is ignored */
1611 	p++;
1612 	ca->maxreq_sz = be32_to_cpup(p++);
1613 	ca->maxresp_sz = be32_to_cpup(p++);
1614 	ca->maxresp_cached = be32_to_cpup(p++);
1615 	ca->maxops = be32_to_cpup(p++);
1616 	ca->maxreqs = be32_to_cpup(p++);
1617 	ca->nr_rdma_attrs = be32_to_cpup(p);
1618 	switch (ca->nr_rdma_attrs) {
1619 	case 0:
1620 		break;
1621 	case 1:
1622 		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
1623 			return nfserr_bad_xdr;
1624 		break;
1625 	default:
1626 		return nfserr_bad_xdr;
1627 	}
1628 
1629 	return nfs_ok;
1630 }
1631 
1632 static __be32
1633 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1634 			    struct nfsd4_create_session *sess)
1635 {
1636 	__be32 status;
1637 
1638 	status = nfsd4_decode_clientid4(argp, &sess->clientid);
1639 	if (status)
1640 		return status;
1641 	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
1642 		return nfserr_bad_xdr;
1643 	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
1644 		return nfserr_bad_xdr;
1645 	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
1646 	if (status)
1647 		return status;
1648 	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
1649 	if (status)
1650 		return status;
1651 	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
1652 		return nfserr_bad_xdr;
1653 	status = nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1654 	if (status)
1655 		return status;
1656 
1657 	return nfs_ok;
1658 }
1659 
1660 static __be32
1661 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1662 			     struct nfsd4_destroy_session *destroy_session)
1663 {
1664 	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
1665 }
1666 
1667 static __be32
1668 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1669 			  struct nfsd4_free_stateid *free_stateid)
1670 {
1671 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
1672 }
1673 
1674 #ifdef CONFIG_NFSD_PNFS
1675 static __be32
1676 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1677 		struct nfsd4_getdeviceinfo *gdev)
1678 {
1679 	__be32 status;
1680 
1681 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1682 	if (status)
1683 		return status;
1684 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1685 		return nfserr_bad_xdr;
1686 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1687 		return nfserr_bad_xdr;
1688 	if (xdr_stream_decode_uint32_array(argp->xdr,
1689 					   &gdev->gd_notify_types, 1) < 0)
1690 		return nfserr_bad_xdr;
1691 
1692 	return nfs_ok;
1693 }
1694 
1695 static __be32
1696 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1697 			  struct nfsd4_layoutcommit *lcp)
1698 {
1699 	__be32 *p, status;
1700 
1701 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1702 		return nfserr_bad_xdr;
1703 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1704 		return nfserr_bad_xdr;
1705 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1706 		return nfserr_bad_xdr;
1707 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1708 	if (status)
1709 		return status;
1710 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1711 		return nfserr_bad_xdr;
1712 	if (lcp->lc_newoffset) {
1713 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1714 			return nfserr_bad_xdr;
1715 	} else
1716 		lcp->lc_last_wr = 0;
1717 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1718 	if (!p)
1719 		return nfserr_bad_xdr;
1720 	if (xdr_item_is_present(p)) {
1721 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1722 		if (status)
1723 			return status;
1724 	} else {
1725 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1726 	}
1727 	return nfsd4_decode_layoutupdate4(argp, lcp);
1728 }
1729 
1730 static __be32
1731 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1732 		struct nfsd4_layoutget *lgp)
1733 {
1734 	__be32 status;
1735 
1736 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1737 		return nfserr_bad_xdr;
1738 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1739 		return nfserr_bad_xdr;
1740 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1741 		return nfserr_bad_xdr;
1742 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1743 		return nfserr_bad_xdr;
1744 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1745 		return nfserr_bad_xdr;
1746 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1747 		return nfserr_bad_xdr;
1748 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1749 	if (status)
1750 		return status;
1751 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1752 		return nfserr_bad_xdr;
1753 
1754 	return nfs_ok;
1755 }
1756 
1757 static __be32
1758 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1759 		struct nfsd4_layoutreturn *lrp)
1760 {
1761 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1762 		return nfserr_bad_xdr;
1763 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1764 		return nfserr_bad_xdr;
1765 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1766 		return nfserr_bad_xdr;
1767 	return nfsd4_decode_layoutreturn4(argp, lrp);
1768 }
1769 #endif /* CONFIG_NFSD_PNFS */
1770 
1771 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1772 					   struct nfsd4_secinfo_no_name *sin)
1773 {
1774 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1775 		return nfserr_bad_xdr;
1776 	return nfs_ok;
1777 }
1778 
1779 static __be32
1780 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1781 		      struct nfsd4_sequence *seq)
1782 {
1783 	__be32 *p, status;
1784 
1785 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1786 	if (status)
1787 		return status;
1788 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1789 	if (!p)
1790 		return nfserr_bad_xdr;
1791 	seq->seqid = be32_to_cpup(p++);
1792 	seq->slotid = be32_to_cpup(p++);
1793 	seq->maxslots = be32_to_cpup(p++);
1794 	seq->cachethis = be32_to_cpup(p);
1795 
1796 	return nfs_ok;
1797 }
1798 
1799 static __be32
1800 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1801 {
1802 	struct nfsd4_test_stateid_id *stateid;
1803 	__be32 status;
1804 	u32 i;
1805 
1806 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1807 		return nfserr_bad_xdr;
1808 
1809 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1810 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1811 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1812 		if (!stateid)
1813 			return nfserr_jukebox;
1814 		INIT_LIST_HEAD(&stateid->ts_id_list);
1815 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1816 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1817 		if (status)
1818 			return status;
1819 	}
1820 
1821 	return nfs_ok;
1822 }
1823 
1824 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1825 					    struct nfsd4_destroy_clientid *dc)
1826 {
1827 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1828 }
1829 
1830 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1831 					    struct nfsd4_reclaim_complete *rc)
1832 {
1833 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1834 		return nfserr_bad_xdr;
1835 	return nfs_ok;
1836 }
1837 
1838 static __be32
1839 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1840 		       struct nfsd4_fallocate *fallocate)
1841 {
1842 	__be32 status;
1843 
1844 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1845 	if (status)
1846 		return status;
1847 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1848 		return nfserr_bad_xdr;
1849 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1850 		return nfserr_bad_xdr;
1851 
1852 	return nfs_ok;
1853 }
1854 
1855 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1856 				      struct nl4_server *ns)
1857 {
1858 	struct nfs42_netaddr *naddr;
1859 	__be32 *p;
1860 
1861 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1862 		return nfserr_bad_xdr;
1863 
1864 	/* currently support for 1 inter-server source server */
1865 	switch (ns->nl4_type) {
1866 	case NL4_NETADDR:
1867 		naddr = &ns->u.nl4_addr;
1868 
1869 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1870 			return nfserr_bad_xdr;
1871 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1872 			return nfserr_bad_xdr;
1873 
1874 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1875 		if (!p)
1876 			return nfserr_bad_xdr;
1877 		memcpy(naddr->netid, p, naddr->netid_len);
1878 
1879 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1880 			return nfserr_bad_xdr;
1881 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1882 			return nfserr_bad_xdr;
1883 
1884 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1885 		if (!p)
1886 			return nfserr_bad_xdr;
1887 		memcpy(naddr->addr, p, naddr->addr_len);
1888 		break;
1889 	default:
1890 		return nfserr_bad_xdr;
1891 	}
1892 
1893 	return nfs_ok;
1894 }
1895 
1896 static __be32
1897 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
1898 {
1899 	u32 consecutive, i, count, sync;
1900 	struct nl4_server *ns_dummy;
1901 	__be32 status;
1902 
1903 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
1904 	if (status)
1905 		return status;
1906 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
1907 	if (status)
1908 		return status;
1909 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
1910 		return nfserr_bad_xdr;
1911 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
1912 		return nfserr_bad_xdr;
1913 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
1914 		return nfserr_bad_xdr;
1915 	/* ca_consecutive: we always do consecutive copies */
1916 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
1917 		return nfserr_bad_xdr;
1918 	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
1919 		return nfserr_bad_xdr;
1920 	nfsd4_copy_set_sync(copy, sync);
1921 
1922 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1923 		return nfserr_bad_xdr;
1924 	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
1925 	if (copy->cp_src == NULL)
1926 		return nfserr_jukebox;
1927 	if (count == 0) { /* intra-server copy */
1928 		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
1929 		return nfs_ok;
1930 	}
1931 
1932 	/* decode all the supplied server addresses but use only the first */
1933 	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
1934 	if (status)
1935 		return status;
1936 
1937 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
1938 	if (ns_dummy == NULL)
1939 		return nfserr_jukebox;
1940 	for (i = 0; i < count - 1; i++) {
1941 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
1942 		if (status) {
1943 			kfree(ns_dummy);
1944 			return status;
1945 		}
1946 	}
1947 	kfree(ns_dummy);
1948 
1949 	return nfs_ok;
1950 }
1951 
1952 static __be32
1953 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
1954 			 struct nfsd4_copy_notify *cn)
1955 {
1956 	__be32 status;
1957 
1958 	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
1959 	if (cn->cpn_src == NULL)
1960 		return nfserr_jukebox;
1961 	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
1962 	if (cn->cpn_dst == NULL)
1963 		return nfserr_jukebox;
1964 
1965 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
1966 	if (status)
1967 		return status;
1968 	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
1969 }
1970 
1971 static __be32
1972 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
1973 			    struct nfsd4_offload_status *os)
1974 {
1975 	return nfsd4_decode_stateid4(argp, &os->stateid);
1976 }
1977 
1978 static __be32
1979 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
1980 {
1981 	__be32 status;
1982 
1983 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
1984 	if (status)
1985 		return status;
1986 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
1987 		return nfserr_bad_xdr;
1988 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
1989 		return nfserr_bad_xdr;
1990 
1991 	return nfs_ok;
1992 }
1993 
1994 static __be32
1995 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
1996 {
1997 	__be32 status;
1998 
1999 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
2000 	if (status)
2001 		return status;
2002 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
2003 	if (status)
2004 		return status;
2005 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
2006 		return nfserr_bad_xdr;
2007 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
2008 		return nfserr_bad_xdr;
2009 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
2010 		return nfserr_bad_xdr;
2011 
2012 	return nfs_ok;
2013 }
2014 
2015 /*
2016  * XDR data that is more than PAGE_SIZE in size is normally part of a
2017  * read or write. However, the size of extended attributes is limited
2018  * by the maximum request size, and then further limited by the underlying
2019  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2020  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2021  * and we're not dealing with contiguous pages, we need to do some copying.
2022  */
2023 
2024 /*
2025  * Decode data into buffer.
2026  */
2027 static __be32
2028 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2029 		       char **bufp, u32 buflen)
2030 {
2031 	struct page **pages = xdr->pages;
2032 	struct kvec *head = xdr->head;
2033 	char *tmp, *dp;
2034 	u32 len;
2035 
2036 	if (buflen <= head->iov_len) {
2037 		/*
2038 		 * We're in luck, the head has enough space. Just return
2039 		 * the head, no need for copying.
2040 		 */
2041 		*bufp = head->iov_base;
2042 		return 0;
2043 	}
2044 
2045 	tmp = svcxdr_tmpalloc(argp, buflen);
2046 	if (tmp == NULL)
2047 		return nfserr_jukebox;
2048 
2049 	dp = tmp;
2050 	memcpy(dp, head->iov_base, head->iov_len);
2051 	buflen -= head->iov_len;
2052 	dp += head->iov_len;
2053 
2054 	while (buflen > 0) {
2055 		len = min_t(u32, buflen, PAGE_SIZE);
2056 		memcpy(dp, page_address(*pages), len);
2057 
2058 		buflen -= len;
2059 		dp += len;
2060 		pages++;
2061 	}
2062 
2063 	*bufp = tmp;
2064 	return 0;
2065 }
2066 
2067 /*
2068  * Get a user extended attribute name from the XDR buffer.
2069  * It will not have the "user." prefix, so prepend it.
2070  * Lastly, check for nul characters in the name.
2071  */
2072 static __be32
2073 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2074 {
2075 	char *name, *sp, *dp;
2076 	u32 namelen, cnt;
2077 	__be32 *p;
2078 
2079 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2080 		return nfserr_bad_xdr;
2081 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2082 		return nfserr_nametoolong;
2083 	if (namelen == 0)
2084 		return nfserr_bad_xdr;
2085 	p = xdr_inline_decode(argp->xdr, namelen);
2086 	if (!p)
2087 		return nfserr_bad_xdr;
2088 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2089 	if (!name)
2090 		return nfserr_jukebox;
2091 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2092 
2093 	/*
2094 	 * Copy the extended attribute name over while checking for 0
2095 	 * characters.
2096 	 */
2097 	sp = (char *)p;
2098 	dp = name + XATTR_USER_PREFIX_LEN;
2099 	cnt = namelen;
2100 
2101 	while (cnt-- > 0) {
2102 		if (*sp == '\0')
2103 			return nfserr_bad_xdr;
2104 		*dp++ = *sp++;
2105 	}
2106 	*dp = '\0';
2107 
2108 	*namep = name;
2109 
2110 	return nfs_ok;
2111 }
2112 
2113 /*
2114  * A GETXATTR op request comes without a length specifier. We just set the
2115  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2116  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2117  * check it against getxa_len, and allocate + return the value.
2118  */
2119 static __be32
2120 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2121 		      struct nfsd4_getxattr *getxattr)
2122 {
2123 	__be32 status;
2124 	u32 maxcount;
2125 
2126 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2127 	if (status)
2128 		return status;
2129 
2130 	maxcount = svc_max_payload(argp->rqstp);
2131 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2132 
2133 	getxattr->getxa_len = maxcount;
2134 
2135 	return status;
2136 }
2137 
2138 static __be32
2139 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2140 		      struct nfsd4_setxattr *setxattr)
2141 {
2142 	u32 flags, maxcount, size;
2143 	__be32 status;
2144 
2145 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2146 		return nfserr_bad_xdr;
2147 
2148 	if (flags > SETXATTR4_REPLACE)
2149 		return nfserr_inval;
2150 	setxattr->setxa_flags = flags;
2151 
2152 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2153 	if (status)
2154 		return status;
2155 
2156 	maxcount = svc_max_payload(argp->rqstp);
2157 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2158 
2159 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2160 		return nfserr_bad_xdr;
2161 	if (size > maxcount)
2162 		return nfserr_xattr2big;
2163 
2164 	setxattr->setxa_len = size;
2165 	if (size > 0) {
2166 		struct xdr_buf payload;
2167 
2168 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2169 			return nfserr_bad_xdr;
2170 		status = nfsd4_vbuf_from_vector(argp, &payload,
2171 						&setxattr->setxa_buf, size);
2172 	}
2173 
2174 	return nfs_ok;
2175 }
2176 
2177 static __be32
2178 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2179 			struct nfsd4_listxattrs *listxattrs)
2180 {
2181 	u32 maxcount;
2182 
2183 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2184 		return nfserr_bad_xdr;
2185 
2186 	/*
2187 	 * If the cookie  is too large to have even one user.x attribute
2188 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2189 	 */
2190 	if (listxattrs->lsxa_cookie >=
2191 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2192 		return nfserr_badcookie;
2193 
2194 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2195 		return nfserr_bad_xdr;
2196 	if (maxcount < 8)
2197 		/* Always need at least 2 words (length and one character) */
2198 		return nfserr_inval;
2199 
2200 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2201 	listxattrs->lsxa_maxcount = maxcount;
2202 
2203 	return nfs_ok;
2204 }
2205 
2206 static __be32
2207 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2208 			 struct nfsd4_removexattr *removexattr)
2209 {
2210 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2211 }
2212 
2213 static __be32
2214 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
2215 {
2216 	return nfs_ok;
2217 }
2218 
2219 static __be32
2220 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
2221 {
2222 	return nfserr_notsupp;
2223 }
2224 
2225 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
2226 
2227 static const nfsd4_dec nfsd4_dec_ops[] = {
2228 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
2229 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
2230 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
2231 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
2232 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2233 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
2234 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
2235 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
2236 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
2237 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
2238 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
2239 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
2240 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
2241 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
2242 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2243 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
2244 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
2245 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
2246 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
2247 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
2248 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
2249 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
2250 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
2251 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
2252 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
2253 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
2254 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
2255 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
2256 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
2257 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
2258 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
2259 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
2260 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
2261 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
2262 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2263 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
2264 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
2265 
2266 	/* new operations for NFSv4.1 */
2267 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
2268 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
2269 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
2270 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
2271 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
2272 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
2273 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2274 #ifdef CONFIG_NFSD_PNFS
2275 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
2276 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2277 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
2278 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
2279 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
2280 #else
2281 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
2282 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2283 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
2284 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
2285 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
2286 #endif
2287 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
2288 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
2289 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
2290 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
2291 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2292 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
2293 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
2294 
2295 	/* new operations for NFSv4.2 */
2296 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2297 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
2298 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_copy_notify,
2299 	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2300 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2301 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
2302 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
2303 	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
2304 	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
2305 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_read,
2306 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
2307 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
2308 	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
2309 	/* RFC 8276 extended atributes operations */
2310 	[OP_GETXATTR]		= (nfsd4_dec)nfsd4_decode_getxattr,
2311 	[OP_SETXATTR]		= (nfsd4_dec)nfsd4_decode_setxattr,
2312 	[OP_LISTXATTRS]		= (nfsd4_dec)nfsd4_decode_listxattrs,
2313 	[OP_REMOVEXATTR]	= (nfsd4_dec)nfsd4_decode_removexattr,
2314 };
2315 
2316 static inline bool
2317 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2318 {
2319 	if (op->opnum < FIRST_NFS4_OP)
2320 		return false;
2321 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2322 		return false;
2323 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2324 		return false;
2325 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2326 		return false;
2327 	return true;
2328 }
2329 
2330 static bool
2331 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2332 {
2333 	struct nfsd4_op *op;
2334 	bool cachethis = false;
2335 	int auth_slack= argp->rqstp->rq_auth_slack;
2336 	int max_reply = auth_slack + 8; /* opcnt, status */
2337 	int readcount = 0;
2338 	int readbytes = 0;
2339 	__be32 *p;
2340 	int i;
2341 
2342 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2343 		return false;
2344 	max_reply += XDR_UNIT;
2345 	argp->tag = NULL;
2346 	if (unlikely(argp->taglen)) {
2347 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2348 			return false;
2349 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2350 		if (!p)
2351 			return false;
2352 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2353 		if (!argp->tag)
2354 			return false;
2355 		max_reply += xdr_align_size(argp->taglen);
2356 	}
2357 
2358 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2359 		return false;
2360 	if (xdr_stream_decode_u32(argp->xdr, &argp->opcnt) < 0)
2361 		return false;
2362 
2363 	/*
2364 	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
2365 	 * here, so we return success at the xdr level so that
2366 	 * nfsd4_proc can handle this is an NFS-level error.
2367 	 */
2368 	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
2369 		return true;
2370 
2371 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2372 		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
2373 		if (!argp->ops) {
2374 			argp->ops = argp->iops;
2375 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
2376 			return false;
2377 		}
2378 	}
2379 
2380 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2381 		argp->opcnt = 0;
2382 
2383 	for (i = 0; i < argp->opcnt; i++) {
2384 		op = &argp->ops[i];
2385 		op->replay = NULL;
2386 
2387 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2388 			return false;
2389 		if (nfsd4_opnum_in_range(argp, op)) {
2390 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2391 			if (op->status != nfs_ok)
2392 				trace_nfsd_compound_decode_err(argp->rqstp,
2393 							       argp->opcnt, i,
2394 							       op->opnum,
2395 							       op->status);
2396 		} else {
2397 			op->opnum = OP_ILLEGAL;
2398 			op->status = nfserr_op_illegal;
2399 		}
2400 		op->opdesc = OPDESC(op);
2401 		/*
2402 		 * We'll try to cache the result in the DRC if any one
2403 		 * op in the compound wants to be cached:
2404 		 */
2405 		cachethis |= nfsd4_cache_this_op(op);
2406 
2407 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2408 			readcount++;
2409 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2410 		} else
2411 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2412 		/*
2413 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2414 		 * (Special case because it will just skip encoding this
2415 		 * if it runs out of xdr buffer space, and it is the only
2416 		 * operation that behaves this way.)
2417 		 */
2418 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2419 			max_reply += NFS4_OPAQUE_LIMIT;
2420 
2421 		if (op->status) {
2422 			argp->opcnt = i+1;
2423 			break;
2424 		}
2425 	}
2426 	/* Sessions make the DRC unnecessary: */
2427 	if (argp->minorversion)
2428 		cachethis = false;
2429 	svc_reserve(argp->rqstp, max_reply + readbytes);
2430 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2431 
2432 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2433 		__clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
2434 
2435 	return true;
2436 }
2437 
2438 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
2439 			     struct svc_export *exp)
2440 {
2441 	if (exp->ex_flags & NFSEXP_V4ROOT) {
2442 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
2443 		*p++ = 0;
2444 	} else
2445 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2446 	return p;
2447 }
2448 
2449 /*
2450  * ctime (in NFSv4, time_metadata) is not writeable, and the client
2451  * doesn't really care what resolution could theoretically be stored by
2452  * the filesystem.
2453  *
2454  * The client cares how close together changes can be while still
2455  * guaranteeing ctime changes.  For most filesystems (which have
2456  * timestamps with nanosecond fields) that is limited by the resolution
2457  * of the time returned from current_time() (which I'm assuming to be
2458  * 1/HZ).
2459  */
2460 static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
2461 {
2462 	struct timespec64 ts;
2463 	u32 ns;
2464 
2465 	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
2466 	ts = ns_to_timespec64(ns);
2467 
2468 	p = xdr_encode_hyper(p, ts.tv_sec);
2469 	*p++ = cpu_to_be32(ts.tv_nsec);
2470 
2471 	return p;
2472 }
2473 
2474 static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
2475 {
2476 	*p++ = cpu_to_be32(c->atomic);
2477 	p = xdr_encode_hyper(p, c->before_change);
2478 	p = xdr_encode_hyper(p, c->after_change);
2479 	return p;
2480 }
2481 
2482 /* Encode as an array of strings the string given with components
2483  * separated @sep, escaped with esc_enter and esc_exit.
2484  */
2485 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2486 					  char *components, char esc_enter,
2487 					  char esc_exit)
2488 {
2489 	__be32 *p;
2490 	__be32 pathlen;
2491 	int pathlen_offset;
2492 	int strlen, count=0;
2493 	char *str, *end, *next;
2494 
2495 	dprintk("nfsd4_encode_components(%s)\n", components);
2496 
2497 	pathlen_offset = xdr->buf->len;
2498 	p = xdr_reserve_space(xdr, 4);
2499 	if (!p)
2500 		return nfserr_resource;
2501 	p++; /* We will fill this in with @count later */
2502 
2503 	end = str = components;
2504 	while (*end) {
2505 		bool found_esc = false;
2506 
2507 		/* try to parse as esc_start, ..., esc_end, sep */
2508 		if (*str == esc_enter) {
2509 			for (; *end && (*end != esc_exit); end++)
2510 				/* find esc_exit or end of string */;
2511 			next = end + 1;
2512 			if (*end && (!*next || *next == sep)) {
2513 				str++;
2514 				found_esc = true;
2515 			}
2516 		}
2517 
2518 		if (!found_esc)
2519 			for (; *end && (*end != sep); end++)
2520 				/* find sep or end of string */;
2521 
2522 		strlen = end - str;
2523 		if (strlen) {
2524 			p = xdr_reserve_space(xdr, strlen + 4);
2525 			if (!p)
2526 				return nfserr_resource;
2527 			p = xdr_encode_opaque(p, str, strlen);
2528 			count++;
2529 		}
2530 		else
2531 			end++;
2532 		if (found_esc)
2533 			end = next;
2534 
2535 		str = end;
2536 	}
2537 	pathlen = htonl(count);
2538 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2539 	return 0;
2540 }
2541 
2542 /* Encode as an array of strings the string given with components
2543  * separated @sep.
2544  */
2545 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2546 				      char *components)
2547 {
2548 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2549 }
2550 
2551 /*
2552  * encode a location element of a fs_locations structure
2553  */
2554 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2555 					struct nfsd4_fs_location *location)
2556 {
2557 	__be32 status;
2558 
2559 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2560 						'[', ']');
2561 	if (status)
2562 		return status;
2563 	status = nfsd4_encode_components(xdr, '/', location->path);
2564 	if (status)
2565 		return status;
2566 	return 0;
2567 }
2568 
2569 /*
2570  * Encode a path in RFC3530 'pathname4' format
2571  */
2572 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2573 				const struct path *root,
2574 				const struct path *path)
2575 {
2576 	struct path cur = *path;
2577 	__be32 *p;
2578 	struct dentry **components = NULL;
2579 	unsigned int ncomponents = 0;
2580 	__be32 err = nfserr_jukebox;
2581 
2582 	dprintk("nfsd4_encode_components(");
2583 
2584 	path_get(&cur);
2585 	/* First walk the path up to the nfsd root, and store the
2586 	 * dentries/path components in an array.
2587 	 */
2588 	for (;;) {
2589 		if (path_equal(&cur, root))
2590 			break;
2591 		if (cur.dentry == cur.mnt->mnt_root) {
2592 			if (follow_up(&cur))
2593 				continue;
2594 			goto out_free;
2595 		}
2596 		if ((ncomponents & 15) == 0) {
2597 			struct dentry **new;
2598 			new = krealloc(components,
2599 					sizeof(*new) * (ncomponents + 16),
2600 					GFP_KERNEL);
2601 			if (!new)
2602 				goto out_free;
2603 			components = new;
2604 		}
2605 		components[ncomponents++] = cur.dentry;
2606 		cur.dentry = dget_parent(cur.dentry);
2607 	}
2608 	err = nfserr_resource;
2609 	p = xdr_reserve_space(xdr, 4);
2610 	if (!p)
2611 		goto out_free;
2612 	*p++ = cpu_to_be32(ncomponents);
2613 
2614 	while (ncomponents) {
2615 		struct dentry *dentry = components[ncomponents - 1];
2616 		unsigned int len;
2617 
2618 		spin_lock(&dentry->d_lock);
2619 		len = dentry->d_name.len;
2620 		p = xdr_reserve_space(xdr, len + 4);
2621 		if (!p) {
2622 			spin_unlock(&dentry->d_lock);
2623 			goto out_free;
2624 		}
2625 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2626 		dprintk("/%pd", dentry);
2627 		spin_unlock(&dentry->d_lock);
2628 		dput(dentry);
2629 		ncomponents--;
2630 	}
2631 
2632 	err = 0;
2633 out_free:
2634 	dprintk(")\n");
2635 	while (ncomponents)
2636 		dput(components[--ncomponents]);
2637 	kfree(components);
2638 	path_put(&cur);
2639 	return err;
2640 }
2641 
2642 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2643 			struct svc_rqst *rqstp, const struct path *path)
2644 {
2645 	struct svc_export *exp_ps;
2646 	__be32 res;
2647 
2648 	exp_ps = rqst_find_fsidzero_export(rqstp);
2649 	if (IS_ERR(exp_ps))
2650 		return nfserrno(PTR_ERR(exp_ps));
2651 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2652 	exp_put(exp_ps);
2653 	return res;
2654 }
2655 
2656 /*
2657  *  encode a fs_locations structure
2658  */
2659 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2660 			struct svc_rqst *rqstp, struct svc_export *exp)
2661 {
2662 	__be32 status;
2663 	int i;
2664 	__be32 *p;
2665 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2666 
2667 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2668 	if (status)
2669 		return status;
2670 	p = xdr_reserve_space(xdr, 4);
2671 	if (!p)
2672 		return nfserr_resource;
2673 	*p++ = cpu_to_be32(fslocs->locations_count);
2674 	for (i=0; i<fslocs->locations_count; i++) {
2675 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2676 		if (status)
2677 			return status;
2678 	}
2679 	return 0;
2680 }
2681 
2682 static u32 nfs4_file_type(umode_t mode)
2683 {
2684 	switch (mode & S_IFMT) {
2685 	case S_IFIFO:	return NF4FIFO;
2686 	case S_IFCHR:	return NF4CHR;
2687 	case S_IFDIR:	return NF4DIR;
2688 	case S_IFBLK:	return NF4BLK;
2689 	case S_IFLNK:	return NF4LNK;
2690 	case S_IFREG:	return NF4REG;
2691 	case S_IFSOCK:	return NF4SOCK;
2692 	default:	return NF4BAD;
2693 	}
2694 }
2695 
2696 static inline __be32
2697 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2698 		     struct nfs4_ace *ace)
2699 {
2700 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2701 		return nfs4_acl_write_who(xdr, ace->whotype);
2702 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2703 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2704 	else
2705 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2706 }
2707 
2708 static inline __be32
2709 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2710 {
2711 	__be32		*p;
2712 	unsigned long	i = hweight_long(layout_types);
2713 
2714 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2715 	if (!p)
2716 		return nfserr_resource;
2717 
2718 	*p++ = cpu_to_be32(i);
2719 
2720 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2721 		if (layout_types & (1 << i))
2722 			*p++ = cpu_to_be32(i);
2723 
2724 	return 0;
2725 }
2726 
2727 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2728 			      FATTR4_WORD0_RDATTR_ERROR)
2729 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2730 #define WORD2_ABSENT_FS_ATTRS 0
2731 
2732 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2733 static inline __be32
2734 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2735 			    void *context, int len)
2736 {
2737 	__be32 *p;
2738 
2739 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2740 	if (!p)
2741 		return nfserr_resource;
2742 
2743 	/*
2744 	 * For now we use a 0 here to indicate the null translation; in
2745 	 * the future we may place a call to translation code here.
2746 	 */
2747 	*p++ = cpu_to_be32(0); /* lfs */
2748 	*p++ = cpu_to_be32(0); /* pi */
2749 	p = xdr_encode_opaque(p, context, len);
2750 	return 0;
2751 }
2752 #else
2753 static inline __be32
2754 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2755 			    void *context, int len)
2756 { return 0; }
2757 #endif
2758 
2759 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2760 {
2761 	/* As per referral draft:  */
2762 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2763 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2764 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2765 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2766 			*rdattr_err = NFSERR_MOVED;
2767 		else
2768 			return nfserr_moved;
2769 	}
2770 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2771 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2772 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2773 	return 0;
2774 }
2775 
2776 
2777 static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
2778 {
2779 	struct path path = exp->ex_path;
2780 	int err;
2781 
2782 	path_get(&path);
2783 	while (follow_up(&path)) {
2784 		if (path.dentry != path.mnt->mnt_root)
2785 			break;
2786 	}
2787 	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2788 	path_put(&path);
2789 	return err;
2790 }
2791 
2792 static __be32
2793 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2794 {
2795 	__be32 *p;
2796 
2797 	if (bmval2) {
2798 		p = xdr_reserve_space(xdr, 16);
2799 		if (!p)
2800 			goto out_resource;
2801 		*p++ = cpu_to_be32(3);
2802 		*p++ = cpu_to_be32(bmval0);
2803 		*p++ = cpu_to_be32(bmval1);
2804 		*p++ = cpu_to_be32(bmval2);
2805 	} else if (bmval1) {
2806 		p = xdr_reserve_space(xdr, 12);
2807 		if (!p)
2808 			goto out_resource;
2809 		*p++ = cpu_to_be32(2);
2810 		*p++ = cpu_to_be32(bmval0);
2811 		*p++ = cpu_to_be32(bmval1);
2812 	} else {
2813 		p = xdr_reserve_space(xdr, 8);
2814 		if (!p)
2815 			goto out_resource;
2816 		*p++ = cpu_to_be32(1);
2817 		*p++ = cpu_to_be32(bmval0);
2818 	}
2819 
2820 	return 0;
2821 out_resource:
2822 	return nfserr_resource;
2823 }
2824 
2825 /*
2826  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2827  * ourselves.
2828  */
2829 static __be32
2830 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2831 		struct svc_export *exp,
2832 		struct dentry *dentry, u32 *bmval,
2833 		struct svc_rqst *rqstp, int ignore_crossmnt)
2834 {
2835 	u32 bmval0 = bmval[0];
2836 	u32 bmval1 = bmval[1];
2837 	u32 bmval2 = bmval[2];
2838 	struct kstat stat;
2839 	struct svc_fh *tempfh = NULL;
2840 	struct kstatfs statfs;
2841 	__be32 *p, *attrlen_p;
2842 	int starting_len = xdr->buf->len;
2843 	int attrlen_offset;
2844 	u32 dummy;
2845 	u64 dummy64;
2846 	u32 rdattr_err = 0;
2847 	__be32 status;
2848 	int err;
2849 	struct nfs4_acl *acl = NULL;
2850 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2851 	void *context = NULL;
2852 	int contextlen;
2853 #endif
2854 	bool contextsupport = false;
2855 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2856 	u32 minorversion = resp->cstate.minorversion;
2857 	struct path path = {
2858 		.mnt	= exp->ex_path.mnt,
2859 		.dentry	= dentry,
2860 	};
2861 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2862 
2863 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2864 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2865 
2866 	if (exp->ex_fslocs.migrated) {
2867 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2868 		if (status)
2869 			goto out;
2870 	}
2871 
2872 	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2873 	if (err)
2874 		goto out_nfserr;
2875 	if (!(stat.result_mask & STATX_BTIME))
2876 		/* underlying FS does not offer btime so we can't share it */
2877 		bmval1 &= ~FATTR4_WORD1_TIME_CREATE;
2878 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
2879 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
2880 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2881 		       FATTR4_WORD1_SPACE_TOTAL))) {
2882 		err = vfs_statfs(&path, &statfs);
2883 		if (err)
2884 			goto out_nfserr;
2885 	}
2886 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2887 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
2888 		status = nfserr_jukebox;
2889 		if (!tempfh)
2890 			goto out;
2891 		fh_init(tempfh, NFS4_FHSIZE);
2892 		status = fh_compose(tempfh, exp, dentry, NULL);
2893 		if (status)
2894 			goto out;
2895 		fhp = tempfh;
2896 	}
2897 	if (bmval0 & FATTR4_WORD0_ACL) {
2898 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2899 		if (err == -EOPNOTSUPP)
2900 			bmval0 &= ~FATTR4_WORD0_ACL;
2901 		else if (err == -EINVAL) {
2902 			status = nfserr_attrnotsupp;
2903 			goto out;
2904 		} else if (err != 0)
2905 			goto out_nfserr;
2906 	}
2907 
2908 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2909 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
2910 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2911 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
2912 			err = security_inode_getsecctx(d_inode(dentry),
2913 						&context, &contextlen);
2914 		else
2915 			err = -EOPNOTSUPP;
2916 		contextsupport = (err == 0);
2917 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2918 			if (err == -EOPNOTSUPP)
2919 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
2920 			else if (err)
2921 				goto out_nfserr;
2922 		}
2923 	}
2924 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2925 
2926 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
2927 	if (status)
2928 		goto out;
2929 
2930 	attrlen_offset = xdr->buf->len;
2931 	attrlen_p = xdr_reserve_space(xdr, XDR_UNIT);
2932 	if (!attrlen_p)
2933 		goto out_resource;
2934 
2935 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2936 		u32 supp[3];
2937 
2938 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2939 
2940 		if (!IS_POSIXACL(dentry->d_inode))
2941 			supp[0] &= ~FATTR4_WORD0_ACL;
2942 		if (!contextsupport)
2943 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2944 		if (!supp[2]) {
2945 			p = xdr_reserve_space(xdr, 12);
2946 			if (!p)
2947 				goto out_resource;
2948 			*p++ = cpu_to_be32(2);
2949 			*p++ = cpu_to_be32(supp[0]);
2950 			*p++ = cpu_to_be32(supp[1]);
2951 		} else {
2952 			p = xdr_reserve_space(xdr, 16);
2953 			if (!p)
2954 				goto out_resource;
2955 			*p++ = cpu_to_be32(3);
2956 			*p++ = cpu_to_be32(supp[0]);
2957 			*p++ = cpu_to_be32(supp[1]);
2958 			*p++ = cpu_to_be32(supp[2]);
2959 		}
2960 	}
2961 	if (bmval0 & FATTR4_WORD0_TYPE) {
2962 		p = xdr_reserve_space(xdr, 4);
2963 		if (!p)
2964 			goto out_resource;
2965 		dummy = nfs4_file_type(stat.mode);
2966 		if (dummy == NF4BAD) {
2967 			status = nfserr_serverfault;
2968 			goto out;
2969 		}
2970 		*p++ = cpu_to_be32(dummy);
2971 	}
2972 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2973 		p = xdr_reserve_space(xdr, 4);
2974 		if (!p)
2975 			goto out_resource;
2976 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2977 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
2978 		else
2979 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
2980 						NFS4_FH_VOL_RENAME);
2981 	}
2982 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2983 		p = xdr_reserve_space(xdr, 8);
2984 		if (!p)
2985 			goto out_resource;
2986 		p = encode_change(p, &stat, d_inode(dentry), exp);
2987 	}
2988 	if (bmval0 & FATTR4_WORD0_SIZE) {
2989 		p = xdr_reserve_space(xdr, 8);
2990 		if (!p)
2991 			goto out_resource;
2992 		p = xdr_encode_hyper(p, stat.size);
2993 	}
2994 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2995 		p = xdr_reserve_space(xdr, 4);
2996 		if (!p)
2997 			goto out_resource;
2998 		*p++ = cpu_to_be32(1);
2999 	}
3000 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
3001 		p = xdr_reserve_space(xdr, 4);
3002 		if (!p)
3003 			goto out_resource;
3004 		*p++ = cpu_to_be32(1);
3005 	}
3006 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
3007 		p = xdr_reserve_space(xdr, 4);
3008 		if (!p)
3009 			goto out_resource;
3010 		*p++ = cpu_to_be32(0);
3011 	}
3012 	if (bmval0 & FATTR4_WORD0_FSID) {
3013 		p = xdr_reserve_space(xdr, 16);
3014 		if (!p)
3015 			goto out_resource;
3016 		if (exp->ex_fslocs.migrated) {
3017 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
3018 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
3019 		} else switch(fsid_source(fhp)) {
3020 		case FSIDSOURCE_FSID:
3021 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
3022 			p = xdr_encode_hyper(p, (u64)0);
3023 			break;
3024 		case FSIDSOURCE_DEV:
3025 			*p++ = cpu_to_be32(0);
3026 			*p++ = cpu_to_be32(MAJOR(stat.dev));
3027 			*p++ = cpu_to_be32(0);
3028 			*p++ = cpu_to_be32(MINOR(stat.dev));
3029 			break;
3030 		case FSIDSOURCE_UUID:
3031 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
3032 								EX_UUID_LEN);
3033 			break;
3034 		}
3035 	}
3036 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
3037 		p = xdr_reserve_space(xdr, 4);
3038 		if (!p)
3039 			goto out_resource;
3040 		*p++ = cpu_to_be32(0);
3041 	}
3042 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
3043 		p = xdr_reserve_space(xdr, 4);
3044 		if (!p)
3045 			goto out_resource;
3046 		*p++ = cpu_to_be32(nn->nfsd4_lease);
3047 	}
3048 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
3049 		p = xdr_reserve_space(xdr, 4);
3050 		if (!p)
3051 			goto out_resource;
3052 		*p++ = cpu_to_be32(rdattr_err);
3053 	}
3054 	if (bmval0 & FATTR4_WORD0_ACL) {
3055 		struct nfs4_ace *ace;
3056 
3057 		if (acl == NULL) {
3058 			p = xdr_reserve_space(xdr, 4);
3059 			if (!p)
3060 				goto out_resource;
3061 
3062 			*p++ = cpu_to_be32(0);
3063 			goto out_acl;
3064 		}
3065 		p = xdr_reserve_space(xdr, 4);
3066 		if (!p)
3067 			goto out_resource;
3068 		*p++ = cpu_to_be32(acl->naces);
3069 
3070 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3071 			p = xdr_reserve_space(xdr, 4*3);
3072 			if (!p)
3073 				goto out_resource;
3074 			*p++ = cpu_to_be32(ace->type);
3075 			*p++ = cpu_to_be32(ace->flag);
3076 			*p++ = cpu_to_be32(ace->access_mask &
3077 							NFS4_ACE_MASK_ALL);
3078 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
3079 			if (status)
3080 				goto out;
3081 		}
3082 	}
3083 out_acl:
3084 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
3085 		p = xdr_reserve_space(xdr, 4);
3086 		if (!p)
3087 			goto out_resource;
3088 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
3089 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
3090 	}
3091 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
3092 		p = xdr_reserve_space(xdr, 4);
3093 		if (!p)
3094 			goto out_resource;
3095 		*p++ = cpu_to_be32(1);
3096 	}
3097 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
3098 		p = xdr_reserve_space(xdr, 4);
3099 		if (!p)
3100 			goto out_resource;
3101 		*p++ = cpu_to_be32(0);
3102 	}
3103 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
3104 		p = xdr_reserve_space(xdr, 4);
3105 		if (!p)
3106 			goto out_resource;
3107 		*p++ = cpu_to_be32(1);
3108 	}
3109 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
3110 		p = xdr_reserve_space(xdr, 4);
3111 		if (!p)
3112 			goto out_resource;
3113 		*p++ = cpu_to_be32(1);
3114 	}
3115 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
3116 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
3117 		if (!p)
3118 			goto out_resource;
3119 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw,
3120 					fhp->fh_handle.fh_size);
3121 	}
3122 	if (bmval0 & FATTR4_WORD0_FILEID) {
3123 		p = xdr_reserve_space(xdr, 8);
3124 		if (!p)
3125 			goto out_resource;
3126 		p = xdr_encode_hyper(p, stat.ino);
3127 	}
3128 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
3129 		p = xdr_reserve_space(xdr, 8);
3130 		if (!p)
3131 			goto out_resource;
3132 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3133 	}
3134 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
3135 		p = xdr_reserve_space(xdr, 8);
3136 		if (!p)
3137 			goto out_resource;
3138 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3139 	}
3140 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
3141 		p = xdr_reserve_space(xdr, 8);
3142 		if (!p)
3143 			goto out_resource;
3144 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
3145 	}
3146 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
3147 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
3148 		if (status)
3149 			goto out;
3150 	}
3151 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
3152 		p = xdr_reserve_space(xdr, 4);
3153 		if (!p)
3154 			goto out_resource;
3155 		*p++ = cpu_to_be32(1);
3156 	}
3157 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
3158 		p = xdr_reserve_space(xdr, 8);
3159 		if (!p)
3160 			goto out_resource;
3161 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
3162 	}
3163 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
3164 		p = xdr_reserve_space(xdr, 4);
3165 		if (!p)
3166 			goto out_resource;
3167 		*p++ = cpu_to_be32(255);
3168 	}
3169 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
3170 		p = xdr_reserve_space(xdr, 4);
3171 		if (!p)
3172 			goto out_resource;
3173 		*p++ = cpu_to_be32(statfs.f_namelen);
3174 	}
3175 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
3176 		p = xdr_reserve_space(xdr, 8);
3177 		if (!p)
3178 			goto out_resource;
3179 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3180 	}
3181 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
3182 		p = xdr_reserve_space(xdr, 8);
3183 		if (!p)
3184 			goto out_resource;
3185 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3186 	}
3187 	if (bmval1 & FATTR4_WORD1_MODE) {
3188 		p = xdr_reserve_space(xdr, 4);
3189 		if (!p)
3190 			goto out_resource;
3191 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
3192 	}
3193 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
3194 		p = xdr_reserve_space(xdr, 4);
3195 		if (!p)
3196 			goto out_resource;
3197 		*p++ = cpu_to_be32(1);
3198 	}
3199 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
3200 		p = xdr_reserve_space(xdr, 4);
3201 		if (!p)
3202 			goto out_resource;
3203 		*p++ = cpu_to_be32(stat.nlink);
3204 	}
3205 	if (bmval1 & FATTR4_WORD1_OWNER) {
3206 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
3207 		if (status)
3208 			goto out;
3209 	}
3210 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
3211 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
3212 		if (status)
3213 			goto out;
3214 	}
3215 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
3216 		p = xdr_reserve_space(xdr, 8);
3217 		if (!p)
3218 			goto out_resource;
3219 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
3220 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
3221 	}
3222 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
3223 		p = xdr_reserve_space(xdr, 8);
3224 		if (!p)
3225 			goto out_resource;
3226 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
3227 		p = xdr_encode_hyper(p, dummy64);
3228 	}
3229 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
3230 		p = xdr_reserve_space(xdr, 8);
3231 		if (!p)
3232 			goto out_resource;
3233 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
3234 		p = xdr_encode_hyper(p, dummy64);
3235 	}
3236 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
3237 		p = xdr_reserve_space(xdr, 8);
3238 		if (!p)
3239 			goto out_resource;
3240 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
3241 		p = xdr_encode_hyper(p, dummy64);
3242 	}
3243 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
3244 		p = xdr_reserve_space(xdr, 8);
3245 		if (!p)
3246 			goto out_resource;
3247 		dummy64 = (u64)stat.blocks << 9;
3248 		p = xdr_encode_hyper(p, dummy64);
3249 	}
3250 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
3251 		p = xdr_reserve_space(xdr, 12);
3252 		if (!p)
3253 			goto out_resource;
3254 		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
3255 		*p++ = cpu_to_be32(stat.atime.tv_nsec);
3256 	}
3257 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
3258 		p = xdr_reserve_space(xdr, 12);
3259 		if (!p)
3260 			goto out_resource;
3261 		p = encode_time_delta(p, d_inode(dentry));
3262 	}
3263 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
3264 		p = xdr_reserve_space(xdr, 12);
3265 		if (!p)
3266 			goto out_resource;
3267 		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
3268 		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
3269 	}
3270 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
3271 		p = xdr_reserve_space(xdr, 12);
3272 		if (!p)
3273 			goto out_resource;
3274 		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
3275 		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
3276 	}
3277 	if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
3278 		p = xdr_reserve_space(xdr, 12);
3279 		if (!p)
3280 			goto out_resource;
3281 		p = xdr_encode_hyper(p, (s64)stat.btime.tv_sec);
3282 		*p++ = cpu_to_be32(stat.btime.tv_nsec);
3283 	}
3284 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
3285 		struct kstat parent_stat;
3286 		u64 ino = stat.ino;
3287 
3288 		p = xdr_reserve_space(xdr, 8);
3289 		if (!p)
3290                 	goto out_resource;
3291 		/*
3292 		 * Get parent's attributes if not ignoring crossmount
3293 		 * and this is the root of a cross-mounted filesystem.
3294 		 */
3295 		if (ignore_crossmnt == 0 &&
3296 		    dentry == exp->ex_path.mnt->mnt_root) {
3297 			err = get_parent_attributes(exp, &parent_stat);
3298 			if (err)
3299 				goto out_nfserr;
3300 			ino = parent_stat.ino;
3301 		}
3302 		p = xdr_encode_hyper(p, ino);
3303 	}
3304 #ifdef CONFIG_NFSD_PNFS
3305 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
3306 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3307 		if (status)
3308 			goto out;
3309 	}
3310 
3311 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
3312 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3313 		if (status)
3314 			goto out;
3315 	}
3316 
3317 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
3318 		p = xdr_reserve_space(xdr, 4);
3319 		if (!p)
3320 			goto out_resource;
3321 		*p++ = cpu_to_be32(stat.blksize);
3322 	}
3323 #endif /* CONFIG_NFSD_PNFS */
3324 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
3325 		u32 supp[3];
3326 
3327 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
3328 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3329 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3330 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3331 
3332 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
3333 		if (status)
3334 			goto out;
3335 	}
3336 
3337 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3338 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
3339 		status = nfsd4_encode_security_label(xdr, rqstp, context,
3340 								contextlen);
3341 		if (status)
3342 			goto out;
3343 	}
3344 #endif
3345 
3346 	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
3347 		p = xdr_reserve_space(xdr, 4);
3348 		if (!p)
3349 			goto out_resource;
3350 		err = xattr_supported_namespace(d_inode(dentry),
3351 						XATTR_USER_PREFIX);
3352 		*p++ = cpu_to_be32(err == 0);
3353 	}
3354 
3355 	*attrlen_p = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
3356 	status = nfs_ok;
3357 
3358 out:
3359 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3360 	if (context)
3361 		security_release_secctx(context, contextlen);
3362 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3363 	kfree(acl);
3364 	if (tempfh) {
3365 		fh_put(tempfh);
3366 		kfree(tempfh);
3367 	}
3368 	if (status)
3369 		xdr_truncate_encode(xdr, starting_len);
3370 	return status;
3371 out_nfserr:
3372 	status = nfserrno(err);
3373 	goto out;
3374 out_resource:
3375 	status = nfserr_resource;
3376 	goto out;
3377 }
3378 
3379 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3380 				struct xdr_buf *buf, __be32 *p, int bytes)
3381 {
3382 	xdr->scratch.iov_len = 0;
3383 	memset(buf, 0, sizeof(struct xdr_buf));
3384 	buf->head[0].iov_base = p;
3385 	buf->head[0].iov_len = 0;
3386 	buf->len = 0;
3387 	xdr->buf = buf;
3388 	xdr->iov = buf->head;
3389 	xdr->p = p;
3390 	xdr->end = (void *)p + bytes;
3391 	buf->buflen = bytes;
3392 }
3393 
3394 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3395 			struct svc_fh *fhp, struct svc_export *exp,
3396 			struct dentry *dentry, u32 *bmval,
3397 			struct svc_rqst *rqstp, int ignore_crossmnt)
3398 {
3399 	struct xdr_buf dummy;
3400 	struct xdr_stream xdr;
3401 	__be32 ret;
3402 
3403 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3404 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
3405 							ignore_crossmnt);
3406 	*p = xdr.p;
3407 	return ret;
3408 }
3409 
3410 static inline int attributes_need_mount(u32 *bmval)
3411 {
3412 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3413 		return 1;
3414 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3415 		return 1;
3416 	return 0;
3417 }
3418 
3419 static __be32
3420 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
3421 			const char *name, int namlen)
3422 {
3423 	struct svc_export *exp = cd->rd_fhp->fh_export;
3424 	struct dentry *dentry;
3425 	__be32 nfserr;
3426 	int ignore_crossmnt = 0;
3427 
3428 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3429 	if (IS_ERR(dentry))
3430 		return nfserrno(PTR_ERR(dentry));
3431 
3432 	exp_get(exp);
3433 	/*
3434 	 * In the case of a mountpoint, the client may be asking for
3435 	 * attributes that are only properties of the underlying filesystem
3436 	 * as opposed to the cross-mounted file system. In such a case,
3437 	 * we will not follow the cross mount and will fill the attribtutes
3438 	 * directly from the mountpoint dentry.
3439 	 */
3440 	if (nfsd_mountpoint(dentry, exp)) {
3441 		int err;
3442 
3443 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3444 				&& !attributes_need_mount(cd->rd_bmval)) {
3445 			ignore_crossmnt = 1;
3446 			goto out_encode;
3447 		}
3448 		/*
3449 		 * Why the heck aren't we just using nfsd_lookup??
3450 		 * Different "."/".." handling?  Something else?
3451 		 * At least, add a comment here to explain....
3452 		 */
3453 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3454 		if (err) {
3455 			nfserr = nfserrno(err);
3456 			goto out_put;
3457 		}
3458 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3459 		if (nfserr)
3460 			goto out_put;
3461 
3462 	}
3463 out_encode:
3464 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
3465 					cd->rd_rqstp, ignore_crossmnt);
3466 out_put:
3467 	dput(dentry);
3468 	exp_put(exp);
3469 	return nfserr;
3470 }
3471 
3472 static __be32 *
3473 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3474 {
3475 	__be32 *p;
3476 
3477 	p = xdr_reserve_space(xdr, 20);
3478 	if (!p)
3479 		return NULL;
3480 	*p++ = htonl(2);
3481 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3482 	*p++ = htonl(0);			 /* bmval1 */
3483 
3484 	*p++ = htonl(4);     /* attribute length */
3485 	*p++ = nfserr;       /* no htonl */
3486 	return p;
3487 }
3488 
3489 static int
3490 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3491 		    loff_t offset, u64 ino, unsigned int d_type)
3492 {
3493 	struct readdir_cd *ccd = ccdv;
3494 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3495 	struct xdr_stream *xdr = cd->xdr;
3496 	int start_offset = xdr->buf->len;
3497 	int cookie_offset;
3498 	u32 name_and_cookie;
3499 	int entry_bytes;
3500 	__be32 nfserr = nfserr_toosmall;
3501 	__be64 wire_offset;
3502 	__be32 *p;
3503 
3504 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3505 	if (name && isdotent(name, namlen)) {
3506 		cd->common.err = nfs_ok;
3507 		return 0;
3508 	}
3509 
3510 	if (cd->cookie_offset) {
3511 		wire_offset = cpu_to_be64(offset);
3512 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3513 							&wire_offset, 8);
3514 	}
3515 
3516 	p = xdr_reserve_space(xdr, 4);
3517 	if (!p)
3518 		goto fail;
3519 	*p++ = xdr_one;                             /* mark entry present */
3520 	cookie_offset = xdr->buf->len;
3521 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3522 	if (!p)
3523 		goto fail;
3524 	p = xdr_encode_hyper(p, OFFSET_MAX);        /* offset of next entry */
3525 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3526 
3527 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3528 	switch (nfserr) {
3529 	case nfs_ok:
3530 		break;
3531 	case nfserr_resource:
3532 		nfserr = nfserr_toosmall;
3533 		goto fail;
3534 	case nfserr_noent:
3535 		xdr_truncate_encode(xdr, start_offset);
3536 		goto skip_entry;
3537 	default:
3538 		/*
3539 		 * If the client requested the RDATTR_ERROR attribute,
3540 		 * we stuff the error code into this attribute
3541 		 * and continue.  If this attribute was not requested,
3542 		 * then in accordance with the spec, we fail the
3543 		 * entire READDIR operation(!)
3544 		 */
3545 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3546 			goto fail;
3547 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3548 		if (p == NULL) {
3549 			nfserr = nfserr_toosmall;
3550 			goto fail;
3551 		}
3552 	}
3553 	nfserr = nfserr_toosmall;
3554 	entry_bytes = xdr->buf->len - start_offset;
3555 	if (entry_bytes > cd->rd_maxcount)
3556 		goto fail;
3557 	cd->rd_maxcount -= entry_bytes;
3558 	/*
3559 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3560 	 * notes that it could be zero. If it is zero, then the server
3561 	 * should enforce only the rd_maxcount value.
3562 	 */
3563 	if (cd->rd_dircount) {
3564 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3565 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3566 			goto fail;
3567 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3568 		if (!cd->rd_dircount)
3569 			cd->rd_maxcount = 0;
3570 	}
3571 
3572 	cd->cookie_offset = cookie_offset;
3573 skip_entry:
3574 	cd->common.err = nfs_ok;
3575 	return 0;
3576 fail:
3577 	xdr_truncate_encode(xdr, start_offset);
3578 	cd->common.err = nfserr;
3579 	return -EINVAL;
3580 }
3581 
3582 static __be32
3583 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3584 {
3585 	__be32 *p;
3586 
3587 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3588 	if (!p)
3589 		return nfserr_resource;
3590 	*p++ = cpu_to_be32(sid->si_generation);
3591 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3592 					sizeof(stateid_opaque_t));
3593 	return 0;
3594 }
3595 
3596 static __be32
3597 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
3598 {
3599 	struct xdr_stream *xdr = resp->xdr;
3600 	__be32 *p;
3601 
3602 	p = xdr_reserve_space(xdr, 8);
3603 	if (!p)
3604 		return nfserr_resource;
3605 	*p++ = cpu_to_be32(access->ac_supported);
3606 	*p++ = cpu_to_be32(access->ac_resp_access);
3607 	return 0;
3608 }
3609 
3610 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
3611 {
3612 	struct xdr_stream *xdr = resp->xdr;
3613 	__be32 *p;
3614 
3615 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3616 	if (!p)
3617 		return nfserr_resource;
3618 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3619 					NFS4_MAX_SESSIONID_LEN);
3620 	*p++ = cpu_to_be32(bcts->dir);
3621 	/* Upshifting from TCP to RDMA is not supported */
3622 	*p++ = cpu_to_be32(0);
3623 	return 0;
3624 }
3625 
3626 static __be32
3627 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
3628 {
3629 	struct xdr_stream *xdr = resp->xdr;
3630 
3631 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3632 }
3633 
3634 
3635 static __be32
3636 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
3637 {
3638 	struct xdr_stream *xdr = resp->xdr;
3639 	__be32 *p;
3640 
3641 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3642 	if (!p)
3643 		return nfserr_resource;
3644 	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
3645 						NFS4_VERIFIER_SIZE);
3646 	return 0;
3647 }
3648 
3649 static __be32
3650 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
3651 {
3652 	struct xdr_stream *xdr = resp->xdr;
3653 	__be32 *p;
3654 
3655 	p = xdr_reserve_space(xdr, 20);
3656 	if (!p)
3657 		return nfserr_resource;
3658 	encode_cinfo(p, &create->cr_cinfo);
3659 	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3660 			create->cr_bmval[1], create->cr_bmval[2]);
3661 }
3662 
3663 static __be32
3664 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
3665 {
3666 	struct svc_fh *fhp = getattr->ga_fhp;
3667 	struct xdr_stream *xdr = resp->xdr;
3668 
3669 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3670 				    getattr->ga_bmval, resp->rqstp, 0);
3671 }
3672 
3673 static __be32
3674 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
3675 {
3676 	struct xdr_stream *xdr = resp->xdr;
3677 	struct svc_fh *fhp = *fhpp;
3678 	unsigned int len;
3679 	__be32 *p;
3680 
3681 	len = fhp->fh_handle.fh_size;
3682 	p = xdr_reserve_space(xdr, len + 4);
3683 	if (!p)
3684 		return nfserr_resource;
3685 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw, len);
3686 	return 0;
3687 }
3688 
3689 /*
3690 * Including all fields other than the name, a LOCK4denied structure requires
3691 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3692 */
3693 static __be32
3694 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3695 {
3696 	struct xdr_netobj *conf = &ld->ld_owner;
3697 	__be32 *p;
3698 
3699 again:
3700 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3701 	if (!p) {
3702 		/*
3703 		 * Don't fail to return the result just because we can't
3704 		 * return the conflicting open:
3705 		 */
3706 		if (conf->len) {
3707 			kfree(conf->data);
3708 			conf->len = 0;
3709 			conf->data = NULL;
3710 			goto again;
3711 		}
3712 		return nfserr_resource;
3713 	}
3714 	p = xdr_encode_hyper(p, ld->ld_start);
3715 	p = xdr_encode_hyper(p, ld->ld_length);
3716 	*p++ = cpu_to_be32(ld->ld_type);
3717 	if (conf->len) {
3718 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3719 		p = xdr_encode_opaque(p, conf->data, conf->len);
3720 		kfree(conf->data);
3721 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3722 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3723 		*p++ = cpu_to_be32(0); /* length of owner name */
3724 	}
3725 	return nfserr_denied;
3726 }
3727 
3728 static __be32
3729 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
3730 {
3731 	struct xdr_stream *xdr = resp->xdr;
3732 
3733 	if (!nfserr)
3734 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3735 	else if (nfserr == nfserr_denied)
3736 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3737 
3738 	return nfserr;
3739 }
3740 
3741 static __be32
3742 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
3743 {
3744 	struct xdr_stream *xdr = resp->xdr;
3745 
3746 	if (nfserr == nfserr_denied)
3747 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3748 	return nfserr;
3749 }
3750 
3751 static __be32
3752 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
3753 {
3754 	struct xdr_stream *xdr = resp->xdr;
3755 
3756 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3757 }
3758 
3759 
3760 static __be32
3761 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
3762 {
3763 	struct xdr_stream *xdr = resp->xdr;
3764 	__be32 *p;
3765 
3766 	p = xdr_reserve_space(xdr, 20);
3767 	if (!p)
3768 		return nfserr_resource;
3769 	p = encode_cinfo(p, &link->li_cinfo);
3770 	return 0;
3771 }
3772 
3773 
3774 static __be32
3775 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
3776 {
3777 	struct xdr_stream *xdr = resp->xdr;
3778 	__be32 *p;
3779 
3780 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3781 	if (nfserr)
3782 		return nfserr;
3783 	p = xdr_reserve_space(xdr, 24);
3784 	if (!p)
3785 		return nfserr_resource;
3786 	p = encode_cinfo(p, &open->op_cinfo);
3787 	*p++ = cpu_to_be32(open->op_rflags);
3788 
3789 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3790 					open->op_bmval[2]);
3791 	if (nfserr)
3792 		return nfserr;
3793 
3794 	p = xdr_reserve_space(xdr, 4);
3795 	if (!p)
3796 		return nfserr_resource;
3797 
3798 	*p++ = cpu_to_be32(open->op_delegate_type);
3799 	switch (open->op_delegate_type) {
3800 	case NFS4_OPEN_DELEGATE_NONE:
3801 		break;
3802 	case NFS4_OPEN_DELEGATE_READ:
3803 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3804 		if (nfserr)
3805 			return nfserr;
3806 		p = xdr_reserve_space(xdr, 20);
3807 		if (!p)
3808 			return nfserr_resource;
3809 		*p++ = cpu_to_be32(open->op_recall);
3810 
3811 		/*
3812 		 * TODO: ACE's in delegations
3813 		 */
3814 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3815 		*p++ = cpu_to_be32(0);
3816 		*p++ = cpu_to_be32(0);
3817 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3818 		break;
3819 	case NFS4_OPEN_DELEGATE_WRITE:
3820 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3821 		if (nfserr)
3822 			return nfserr;
3823 		p = xdr_reserve_space(xdr, 32);
3824 		if (!p)
3825 			return nfserr_resource;
3826 		*p++ = cpu_to_be32(0);
3827 
3828 		/*
3829 		 * TODO: space_limit's in delegations
3830 		 */
3831 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3832 		*p++ = cpu_to_be32(~(u32)0);
3833 		*p++ = cpu_to_be32(~(u32)0);
3834 
3835 		/*
3836 		 * TODO: ACE's in delegations
3837 		 */
3838 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3839 		*p++ = cpu_to_be32(0);
3840 		*p++ = cpu_to_be32(0);
3841 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3842 		break;
3843 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
3844 		switch (open->op_why_no_deleg) {
3845 		case WND4_CONTENTION:
3846 		case WND4_RESOURCE:
3847 			p = xdr_reserve_space(xdr, 8);
3848 			if (!p)
3849 				return nfserr_resource;
3850 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3851 			/* deleg signaling not supported yet: */
3852 			*p++ = cpu_to_be32(0);
3853 			break;
3854 		default:
3855 			p = xdr_reserve_space(xdr, 4);
3856 			if (!p)
3857 				return nfserr_resource;
3858 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3859 		}
3860 		break;
3861 	default:
3862 		BUG();
3863 	}
3864 	/* XXX save filehandle here */
3865 	return 0;
3866 }
3867 
3868 static __be32
3869 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
3870 {
3871 	struct xdr_stream *xdr = resp->xdr;
3872 
3873 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
3874 }
3875 
3876 static __be32
3877 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
3878 {
3879 	struct xdr_stream *xdr = resp->xdr;
3880 
3881 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
3882 }
3883 
3884 static __be32 nfsd4_encode_splice_read(
3885 				struct nfsd4_compoundres *resp,
3886 				struct nfsd4_read *read,
3887 				struct file *file, unsigned long maxcount)
3888 {
3889 	struct xdr_stream *xdr = resp->xdr;
3890 	struct xdr_buf *buf = xdr->buf;
3891 	int status, space_left;
3892 	__be32 nfserr;
3893 
3894 	/* Make sure there will be room for padding if needed */
3895 	if (xdr->end - xdr->p < 1)
3896 		return nfserr_resource;
3897 
3898 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
3899 				  file, read->rd_offset, &maxcount,
3900 				  &read->rd_eof);
3901 	read->rd_length = maxcount;
3902 	if (nfserr)
3903 		goto out_err;
3904 	status = svc_encode_result_payload(read->rd_rqstp,
3905 					   buf->head[0].iov_len, maxcount);
3906 	if (status) {
3907 		nfserr = nfserrno(status);
3908 		goto out_err;
3909 	}
3910 
3911 	buf->page_len = maxcount;
3912 	buf->len += maxcount;
3913 	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
3914 							/ PAGE_SIZE;
3915 
3916 	/* Use rest of head for padding and remaining ops: */
3917 	buf->tail[0].iov_base = xdr->p;
3918 	buf->tail[0].iov_len = 0;
3919 	xdr->iov = buf->tail;
3920 	if (maxcount&3) {
3921 		int pad = 4 - (maxcount&3);
3922 
3923 		*(xdr->p++) = 0;
3924 
3925 		buf->tail[0].iov_base += maxcount&3;
3926 		buf->tail[0].iov_len = pad;
3927 		buf->len += pad;
3928 	}
3929 
3930 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
3931 				buf->buflen - buf->len);
3932 	buf->buflen = buf->len + space_left;
3933 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
3934 
3935 	return 0;
3936 
3937 out_err:
3938 	/*
3939 	 * nfsd_splice_actor may have already messed with the
3940 	 * page length; reset it so as not to confuse
3941 	 * xdr_truncate_encode in our caller.
3942 	 */
3943 	buf->page_len = 0;
3944 	return nfserr;
3945 }
3946 
3947 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
3948 				 struct nfsd4_read *read,
3949 				 struct file *file, unsigned long maxcount)
3950 {
3951 	struct xdr_stream *xdr = resp->xdr;
3952 	unsigned int starting_len = xdr->buf->len;
3953 	__be32 zero = xdr_zero;
3954 	__be32 nfserr;
3955 
3956 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
3957 	if (read->rd_vlen < 0)
3958 		return nfserr_resource;
3959 
3960 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
3961 			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
3962 			    &read->rd_eof);
3963 	read->rd_length = maxcount;
3964 	if (nfserr)
3965 		return nfserr;
3966 	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
3967 		return nfserr_io;
3968 	xdr_truncate_encode(xdr, starting_len + xdr_align_size(maxcount));
3969 
3970 	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
3971 			       xdr_pad_size(maxcount));
3972 	return nfs_ok;
3973 }
3974 
3975 static __be32
3976 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
3977 		  struct nfsd4_read *read)
3978 {
3979 	bool splice_ok = test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags);
3980 	unsigned long maxcount;
3981 	struct xdr_stream *xdr = resp->xdr;
3982 	struct file *file;
3983 	int starting_len = xdr->buf->len;
3984 	__be32 *p;
3985 
3986 	if (nfserr)
3987 		return nfserr;
3988 	file = read->rd_nf->nf_file;
3989 
3990 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
3991 	if (!p) {
3992 		WARN_ON_ONCE(splice_ok);
3993 		return nfserr_resource;
3994 	}
3995 	if (resp->xdr->buf->page_len && splice_ok) {
3996 		WARN_ON_ONCE(1);
3997 		return nfserr_resource;
3998 	}
3999 	xdr_commit_encode(xdr);
4000 
4001 	maxcount = min_t(unsigned long, read->rd_length,
4002 			 (xdr->buf->buflen - xdr->buf->len));
4003 
4004 	if (file->f_op->splice_read && splice_ok)
4005 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4006 	else
4007 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4008 	if (nfserr) {
4009 		xdr_truncate_encode(xdr, starting_len);
4010 		return nfserr;
4011 	}
4012 
4013 	p = xdr_encode_bool(p, read->rd_eof);
4014 	*p = cpu_to_be32(read->rd_length);
4015 	return nfs_ok;
4016 }
4017 
4018 static __be32
4019 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
4020 {
4021 	__be32 *p, *maxcount_p, zero = xdr_zero;
4022 	struct xdr_stream *xdr = resp->xdr;
4023 	int length_offset = xdr->buf->len;
4024 	int maxcount, status;
4025 
4026 	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
4027 	if (!maxcount_p)
4028 		return nfserr_resource;
4029 	maxcount = PAGE_SIZE;
4030 
4031 	p = xdr_reserve_space(xdr, maxcount);
4032 	if (!p)
4033 		return nfserr_resource;
4034 	/*
4035 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4036 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4037 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4038 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4039 	 */
4040 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4041 						(char *)p, &maxcount);
4042 	if (nfserr == nfserr_isdir)
4043 		nfserr = nfserr_inval;
4044 	if (nfserr)
4045 		goto out_err;
4046 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4047 					   maxcount);
4048 	if (status) {
4049 		nfserr = nfserrno(status);
4050 		goto out_err;
4051 	}
4052 	*maxcount_p = cpu_to_be32(maxcount);
4053 	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
4054 	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
4055 			       xdr_pad_size(maxcount));
4056 	return nfs_ok;
4057 
4058 out_err:
4059 	xdr_truncate_encode(xdr, length_offset);
4060 	return nfserr;
4061 }
4062 
4063 static __be32
4064 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
4065 {
4066 	int maxcount;
4067 	int bytes_left;
4068 	loff_t offset;
4069 	__be64 wire_offset;
4070 	struct xdr_stream *xdr = resp->xdr;
4071 	int starting_len = xdr->buf->len;
4072 	__be32 *p;
4073 
4074 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
4075 	if (!p)
4076 		return nfserr_resource;
4077 
4078 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
4079 	*p++ = cpu_to_be32(0);
4080 	*p++ = cpu_to_be32(0);
4081 	xdr->buf->head[0].iov_len = (char *)xdr->p -
4082 				    (char *)xdr->buf->head[0].iov_base;
4083 
4084 	/*
4085 	 * Number of bytes left for directory entries allowing for the
4086 	 * final 8 bytes of the readdir and a following failed op:
4087 	 */
4088 	bytes_left = xdr->buf->buflen - xdr->buf->len
4089 			- COMPOUND_ERR_SLACK_SPACE - 8;
4090 	if (bytes_left < 0) {
4091 		nfserr = nfserr_resource;
4092 		goto err_no_verf;
4093 	}
4094 	maxcount = svc_max_payload(resp->rqstp);
4095 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
4096 	/*
4097 	 * Note the rfc defines rd_maxcount as the size of the
4098 	 * READDIR4resok structure, which includes the verifier above
4099 	 * and the 8 bytes encoded at the end of this function:
4100 	 */
4101 	if (maxcount < 16) {
4102 		nfserr = nfserr_toosmall;
4103 		goto err_no_verf;
4104 	}
4105 	maxcount = min_t(int, maxcount-16, bytes_left);
4106 
4107 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
4108 	if (!readdir->rd_dircount)
4109 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
4110 
4111 	readdir->xdr = xdr;
4112 	readdir->rd_maxcount = maxcount;
4113 	readdir->common.err = 0;
4114 	readdir->cookie_offset = 0;
4115 
4116 	offset = readdir->rd_cookie;
4117 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
4118 			      &offset,
4119 			      &readdir->common, nfsd4_encode_dirent);
4120 	if (nfserr == nfs_ok &&
4121 	    readdir->common.err == nfserr_toosmall &&
4122 	    xdr->buf->len == starting_len + 8) {
4123 		/* nothing encoded; which limit did we hit?: */
4124 		if (maxcount - 16 < bytes_left)
4125 			/* It was the fault of rd_maxcount: */
4126 			nfserr = nfserr_toosmall;
4127 		else
4128 			/* We ran out of buffer space: */
4129 			nfserr = nfserr_resource;
4130 	}
4131 	if (nfserr)
4132 		goto err_no_verf;
4133 
4134 	if (readdir->cookie_offset) {
4135 		wire_offset = cpu_to_be64(offset);
4136 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
4137 							&wire_offset, 8);
4138 	}
4139 
4140 	p = xdr_reserve_space(xdr, 8);
4141 	if (!p) {
4142 		WARN_ON_ONCE(1);
4143 		goto err_no_verf;
4144 	}
4145 	*p++ = 0;	/* no more entries */
4146 	*p++ = htonl(readdir->common.err == nfserr_eof);
4147 
4148 	return 0;
4149 err_no_verf:
4150 	xdr_truncate_encode(xdr, starting_len);
4151 	return nfserr;
4152 }
4153 
4154 static __be32
4155 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
4156 {
4157 	struct xdr_stream *xdr = resp->xdr;
4158 	__be32 *p;
4159 
4160 	p = xdr_reserve_space(xdr, 20);
4161 	if (!p)
4162 		return nfserr_resource;
4163 	p = encode_cinfo(p, &remove->rm_cinfo);
4164 	return 0;
4165 }
4166 
4167 static __be32
4168 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
4169 {
4170 	struct xdr_stream *xdr = resp->xdr;
4171 	__be32 *p;
4172 
4173 	p = xdr_reserve_space(xdr, 40);
4174 	if (!p)
4175 		return nfserr_resource;
4176 	p = encode_cinfo(p, &rename->rn_sinfo);
4177 	p = encode_cinfo(p, &rename->rn_tinfo);
4178 	return 0;
4179 }
4180 
4181 static __be32
4182 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4183 {
4184 	u32 i, nflavs, supported;
4185 	struct exp_flavor_info *flavs;
4186 	struct exp_flavor_info def_flavs[2];
4187 	__be32 *p, *flavorsp;
4188 	static bool report = true;
4189 
4190 	if (exp->ex_nflavors) {
4191 		flavs = exp->ex_flavors;
4192 		nflavs = exp->ex_nflavors;
4193 	} else { /* Handling of some defaults in absence of real secinfo: */
4194 		flavs = def_flavs;
4195 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4196 			nflavs = 2;
4197 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4198 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4199 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4200 			nflavs = 1;
4201 			flavs[0].pseudoflavor
4202 					= svcauth_gss_flavor(exp->ex_client);
4203 		} else {
4204 			nflavs = 1;
4205 			flavs[0].pseudoflavor
4206 					= exp->ex_client->flavour->flavour;
4207 		}
4208 	}
4209 
4210 	supported = 0;
4211 	p = xdr_reserve_space(xdr, 4);
4212 	if (!p)
4213 		return nfserr_resource;
4214 	flavorsp = p++;		/* to be backfilled later */
4215 
4216 	for (i = 0; i < nflavs; i++) {
4217 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4218 		struct rpcsec_gss_info info;
4219 
4220 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4221 			supported++;
4222 			p = xdr_reserve_space(xdr, 4 + 4 +
4223 					      XDR_LEN(info.oid.len) + 4 + 4);
4224 			if (!p)
4225 				return nfserr_resource;
4226 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
4227 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
4228 			*p++ = cpu_to_be32(info.qop);
4229 			*p++ = cpu_to_be32(info.service);
4230 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4231 			supported++;
4232 			p = xdr_reserve_space(xdr, 4);
4233 			if (!p)
4234 				return nfserr_resource;
4235 			*p++ = cpu_to_be32(pf);
4236 		} else {
4237 			if (report)
4238 				pr_warn("NFS: SECINFO: security flavor %u "
4239 					"is not supported\n", pf);
4240 		}
4241 	}
4242 
4243 	if (nflavs != supported)
4244 		report = false;
4245 	*flavorsp = htonl(supported);
4246 	return 0;
4247 }
4248 
4249 static __be32
4250 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4251 		     struct nfsd4_secinfo *secinfo)
4252 {
4253 	struct xdr_stream *xdr = resp->xdr;
4254 
4255 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4256 }
4257 
4258 static __be32
4259 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4260 		     struct nfsd4_secinfo_no_name *secinfo)
4261 {
4262 	struct xdr_stream *xdr = resp->xdr;
4263 
4264 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4265 }
4266 
4267 /*
4268  * The SETATTR encode routine is special -- it always encodes a bitmap,
4269  * regardless of the error status.
4270  */
4271 static __be32
4272 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
4273 {
4274 	struct xdr_stream *xdr = resp->xdr;
4275 	__be32 *p;
4276 
4277 	p = xdr_reserve_space(xdr, 16);
4278 	if (!p)
4279 		return nfserr_resource;
4280 	if (nfserr) {
4281 		*p++ = cpu_to_be32(3);
4282 		*p++ = cpu_to_be32(0);
4283 		*p++ = cpu_to_be32(0);
4284 		*p++ = cpu_to_be32(0);
4285 	}
4286 	else {
4287 		*p++ = cpu_to_be32(3);
4288 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
4289 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
4290 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
4291 	}
4292 	return nfserr;
4293 }
4294 
4295 static __be32
4296 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
4297 {
4298 	struct xdr_stream *xdr = resp->xdr;
4299 	__be32 *p;
4300 
4301 	if (!nfserr) {
4302 		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
4303 		if (!p)
4304 			return nfserr_resource;
4305 		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
4306 		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
4307 						NFS4_VERIFIER_SIZE);
4308 	}
4309 	else if (nfserr == nfserr_clid_inuse) {
4310 		p = xdr_reserve_space(xdr, 8);
4311 		if (!p)
4312 			return nfserr_resource;
4313 		*p++ = cpu_to_be32(0);
4314 		*p++ = cpu_to_be32(0);
4315 	}
4316 	return nfserr;
4317 }
4318 
4319 static __be32
4320 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
4321 {
4322 	struct xdr_stream *xdr = resp->xdr;
4323 	__be32 *p;
4324 
4325 	p = xdr_reserve_space(xdr, 16);
4326 	if (!p)
4327 		return nfserr_resource;
4328 	*p++ = cpu_to_be32(write->wr_bytes_written);
4329 	*p++ = cpu_to_be32(write->wr_how_written);
4330 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4331 						NFS4_VERIFIER_SIZE);
4332 	return 0;
4333 }
4334 
4335 static __be32
4336 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4337 			 struct nfsd4_exchange_id *exid)
4338 {
4339 	struct xdr_stream *xdr = resp->xdr;
4340 	__be32 *p;
4341 	char *major_id;
4342 	char *server_scope;
4343 	int major_id_sz;
4344 	int server_scope_sz;
4345 	uint64_t minor_id = 0;
4346 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4347 
4348 	major_id = nn->nfsd_name;
4349 	major_id_sz = strlen(nn->nfsd_name);
4350 	server_scope = nn->nfsd_name;
4351 	server_scope_sz = strlen(nn->nfsd_name);
4352 
4353 	p = xdr_reserve_space(xdr,
4354 		8 /* eir_clientid */ +
4355 		4 /* eir_sequenceid */ +
4356 		4 /* eir_flags */ +
4357 		4 /* spr_how */);
4358 	if (!p)
4359 		return nfserr_resource;
4360 
4361 	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
4362 	*p++ = cpu_to_be32(exid->seqid);
4363 	*p++ = cpu_to_be32(exid->flags);
4364 
4365 	*p++ = cpu_to_be32(exid->spa_how);
4366 
4367 	switch (exid->spa_how) {
4368 	case SP4_NONE:
4369 		break;
4370 	case SP4_MACH_CRED:
4371 		/* spo_must_enforce bitmap: */
4372 		nfserr = nfsd4_encode_bitmap(xdr,
4373 					exid->spo_must_enforce[0],
4374 					exid->spo_must_enforce[1],
4375 					exid->spo_must_enforce[2]);
4376 		if (nfserr)
4377 			return nfserr;
4378 		/* spo_must_allow bitmap: */
4379 		nfserr = nfsd4_encode_bitmap(xdr,
4380 					exid->spo_must_allow[0],
4381 					exid->spo_must_allow[1],
4382 					exid->spo_must_allow[2]);
4383 		if (nfserr)
4384 			return nfserr;
4385 		break;
4386 	default:
4387 		WARN_ON_ONCE(1);
4388 	}
4389 
4390 	p = xdr_reserve_space(xdr,
4391 		8 /* so_minor_id */ +
4392 		4 /* so_major_id.len */ +
4393 		(XDR_QUADLEN(major_id_sz) * 4) +
4394 		4 /* eir_server_scope.len */ +
4395 		(XDR_QUADLEN(server_scope_sz) * 4) +
4396 		4 /* eir_server_impl_id.count (0) */);
4397 	if (!p)
4398 		return nfserr_resource;
4399 
4400 	/* The server_owner struct */
4401 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
4402 	/* major id */
4403 	p = xdr_encode_opaque(p, major_id, major_id_sz);
4404 
4405 	/* Server scope */
4406 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
4407 
4408 	/* Implementation id */
4409 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
4410 	return 0;
4411 }
4412 
4413 static __be32
4414 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4415 			    struct nfsd4_create_session *sess)
4416 {
4417 	struct xdr_stream *xdr = resp->xdr;
4418 	__be32 *p;
4419 
4420 	p = xdr_reserve_space(xdr, 24);
4421 	if (!p)
4422 		return nfserr_resource;
4423 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
4424 					NFS4_MAX_SESSIONID_LEN);
4425 	*p++ = cpu_to_be32(sess->seqid);
4426 	*p++ = cpu_to_be32(sess->flags);
4427 
4428 	p = xdr_reserve_space(xdr, 28);
4429 	if (!p)
4430 		return nfserr_resource;
4431 	*p++ = cpu_to_be32(0); /* headerpadsz */
4432 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
4433 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
4434 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
4435 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4436 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4437 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4438 
4439 	if (sess->fore_channel.nr_rdma_attrs) {
4440 		p = xdr_reserve_space(xdr, 4);
4441 		if (!p)
4442 			return nfserr_resource;
4443 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4444 	}
4445 
4446 	p = xdr_reserve_space(xdr, 28);
4447 	if (!p)
4448 		return nfserr_resource;
4449 	*p++ = cpu_to_be32(0); /* headerpadsz */
4450 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4451 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4452 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4453 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4454 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4455 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4456 
4457 	if (sess->back_channel.nr_rdma_attrs) {
4458 		p = xdr_reserve_space(xdr, 4);
4459 		if (!p)
4460 			return nfserr_resource;
4461 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4462 	}
4463 	return 0;
4464 }
4465 
4466 static __be32
4467 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4468 		      struct nfsd4_sequence *seq)
4469 {
4470 	struct xdr_stream *xdr = resp->xdr;
4471 	__be32 *p;
4472 
4473 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4474 	if (!p)
4475 		return nfserr_resource;
4476 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4477 					NFS4_MAX_SESSIONID_LEN);
4478 	*p++ = cpu_to_be32(seq->seqid);
4479 	*p++ = cpu_to_be32(seq->slotid);
4480 	/* Note slotid's are numbered from zero: */
4481 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4482 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4483 	*p++ = cpu_to_be32(seq->status_flags);
4484 
4485 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4486 	return 0;
4487 }
4488 
4489 static __be32
4490 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4491 			  struct nfsd4_test_stateid *test_stateid)
4492 {
4493 	struct xdr_stream *xdr = resp->xdr;
4494 	struct nfsd4_test_stateid_id *stateid, *next;
4495 	__be32 *p;
4496 
4497 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4498 	if (!p)
4499 		return nfserr_resource;
4500 	*p++ = htonl(test_stateid->ts_num_ids);
4501 
4502 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4503 		*p++ = stateid->ts_id_status;
4504 	}
4505 
4506 	return 0;
4507 }
4508 
4509 #ifdef CONFIG_NFSD_PNFS
4510 static __be32
4511 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4512 		struct nfsd4_getdeviceinfo *gdev)
4513 {
4514 	struct xdr_stream *xdr = resp->xdr;
4515 	const struct nfsd4_layout_ops *ops;
4516 	u32 starting_len = xdr->buf->len, needed_len;
4517 	__be32 *p;
4518 
4519 	p = xdr_reserve_space(xdr, 4);
4520 	if (!p)
4521 		return nfserr_resource;
4522 
4523 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4524 
4525 	/* If maxcount is 0 then just update notifications */
4526 	if (gdev->gd_maxcount != 0) {
4527 		ops = nfsd4_layout_ops[gdev->gd_layout_type];
4528 		nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4529 		if (nfserr) {
4530 			/*
4531 			 * We don't bother to burden the layout drivers with
4532 			 * enforcing gd_maxcount, just tell the client to
4533 			 * come back with a bigger buffer if it's not enough.
4534 			 */
4535 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
4536 				goto toosmall;
4537 			return nfserr;
4538 		}
4539 	}
4540 
4541 	if (gdev->gd_notify_types) {
4542 		p = xdr_reserve_space(xdr, 4 + 4);
4543 		if (!p)
4544 			return nfserr_resource;
4545 		*p++ = cpu_to_be32(1);			/* bitmap length */
4546 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4547 	} else {
4548 		p = xdr_reserve_space(xdr, 4);
4549 		if (!p)
4550 			return nfserr_resource;
4551 		*p++ = 0;
4552 	}
4553 
4554 	return 0;
4555 toosmall:
4556 	dprintk("%s: maxcount too small\n", __func__);
4557 	needed_len = xdr->buf->len + 4 /* notifications */;
4558 	xdr_truncate_encode(xdr, starting_len);
4559 	p = xdr_reserve_space(xdr, 4);
4560 	if (!p)
4561 		return nfserr_resource;
4562 	*p++ = cpu_to_be32(needed_len);
4563 	return nfserr_toosmall;
4564 }
4565 
4566 static __be32
4567 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4568 		struct nfsd4_layoutget *lgp)
4569 {
4570 	struct xdr_stream *xdr = resp->xdr;
4571 	const struct nfsd4_layout_ops *ops;
4572 	__be32 *p;
4573 
4574 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4575 	if (!p)
4576 		return nfserr_resource;
4577 
4578 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4579 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4580 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4581 				    sizeof(stateid_opaque_t));
4582 
4583 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4584 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4585 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4586 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4587 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4588 
4589 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4590 	return ops->encode_layoutget(xdr, lgp);
4591 }
4592 
4593 static __be32
4594 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4595 			  struct nfsd4_layoutcommit *lcp)
4596 {
4597 	struct xdr_stream *xdr = resp->xdr;
4598 	__be32 *p;
4599 
4600 	p = xdr_reserve_space(xdr, 4);
4601 	if (!p)
4602 		return nfserr_resource;
4603 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4604 	if (lcp->lc_size_chg) {
4605 		p = xdr_reserve_space(xdr, 8);
4606 		if (!p)
4607 			return nfserr_resource;
4608 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4609 	}
4610 
4611 	return 0;
4612 }
4613 
4614 static __be32
4615 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4616 		struct nfsd4_layoutreturn *lrp)
4617 {
4618 	struct xdr_stream *xdr = resp->xdr;
4619 	__be32 *p;
4620 
4621 	p = xdr_reserve_space(xdr, 4);
4622 	if (!p)
4623 		return nfserr_resource;
4624 	*p++ = cpu_to_be32(lrp->lrs_present);
4625 	if (lrp->lrs_present)
4626 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4627 	return 0;
4628 }
4629 #endif /* CONFIG_NFSD_PNFS */
4630 
4631 static __be32
4632 nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
4633 		struct nfsd42_write_res *write, bool sync)
4634 {
4635 	__be32 *p;
4636 	p = xdr_reserve_space(resp->xdr, 4);
4637 	if (!p)
4638 		return nfserr_resource;
4639 
4640 	if (sync)
4641 		*p++ = cpu_to_be32(0);
4642 	else {
4643 		__be32 nfserr;
4644 		*p++ = cpu_to_be32(1);
4645 		nfserr = nfsd4_encode_stateid(resp->xdr, &write->cb_stateid);
4646 		if (nfserr)
4647 			return nfserr;
4648 	}
4649 	p = xdr_reserve_space(resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
4650 	if (!p)
4651 		return nfserr_resource;
4652 
4653 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4654 	*p++ = cpu_to_be32(write->wr_stable_how);
4655 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4656 				    NFS4_VERIFIER_SIZE);
4657 	return nfs_ok;
4658 }
4659 
4660 static __be32
4661 nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
4662 {
4663 	struct xdr_stream *xdr = resp->xdr;
4664 	struct nfs42_netaddr *addr;
4665 	__be32 *p;
4666 
4667 	p = xdr_reserve_space(xdr, 4);
4668 	*p++ = cpu_to_be32(ns->nl4_type);
4669 
4670 	switch (ns->nl4_type) {
4671 	case NL4_NETADDR:
4672 		addr = &ns->u.nl4_addr;
4673 
4674 		/* netid_len, netid, uaddr_len, uaddr (port included
4675 		 * in RPCBIND_MAXUADDRLEN)
4676 		 */
4677 		p = xdr_reserve_space(xdr,
4678 			4 /* netid len */ +
4679 			(XDR_QUADLEN(addr->netid_len) * 4) +
4680 			4 /* uaddr len */ +
4681 			(XDR_QUADLEN(addr->addr_len) * 4));
4682 		if (!p)
4683 			return nfserr_resource;
4684 
4685 		*p++ = cpu_to_be32(addr->netid_len);
4686 		p = xdr_encode_opaque_fixed(p, addr->netid,
4687 					    addr->netid_len);
4688 		*p++ = cpu_to_be32(addr->addr_len);
4689 		p = xdr_encode_opaque_fixed(p, addr->addr,
4690 					addr->addr_len);
4691 		break;
4692 	default:
4693 		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
4694 		return nfserr_inval;
4695 	}
4696 
4697 	return 0;
4698 }
4699 
4700 static __be32
4701 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4702 		  struct nfsd4_copy *copy)
4703 {
4704 	__be32 *p;
4705 
4706 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
4707 					 nfsd4_copy_is_sync(copy));
4708 	if (nfserr)
4709 		return nfserr;
4710 
4711 	p = xdr_reserve_space(resp->xdr, 4 + 4);
4712 	*p++ = xdr_one; /* cr_consecutive */
4713 	*p = nfsd4_copy_is_sync(copy) ? xdr_one : xdr_zero;
4714 	return 0;
4715 }
4716 
4717 static __be32
4718 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
4719 			    struct nfsd4_offload_status *os)
4720 {
4721 	struct xdr_stream *xdr = resp->xdr;
4722 	__be32 *p;
4723 
4724 	p = xdr_reserve_space(xdr, 8 + 4);
4725 	if (!p)
4726 		return nfserr_resource;
4727 	p = xdr_encode_hyper(p, os->count);
4728 	*p++ = cpu_to_be32(0);
4729 	return nfserr;
4730 }
4731 
4732 static __be32
4733 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
4734 			    struct nfsd4_read *read,
4735 			    unsigned long *maxcount, u32 *eof,
4736 			    loff_t *pos)
4737 {
4738 	struct xdr_stream *xdr = resp->xdr;
4739 	struct file *file = read->rd_nf->nf_file;
4740 	int starting_len = xdr->buf->len;
4741 	loff_t hole_pos;
4742 	__be32 nfserr;
4743 	__be32 *p, tmp;
4744 	__be64 tmp64;
4745 
4746 	hole_pos = pos ? *pos : vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4747 	if (hole_pos > read->rd_offset)
4748 		*maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
4749 	*maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
4750 
4751 	/* Content type, offset, byte count */
4752 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
4753 	if (!p)
4754 		return nfserr_resource;
4755 
4756 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
4757 	if (read->rd_vlen < 0)
4758 		return nfserr_resource;
4759 
4760 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
4761 			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
4762 	if (nfserr)
4763 		return nfserr;
4764 	xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
4765 
4766 	tmp = htonl(NFS4_CONTENT_DATA);
4767 	write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
4768 	tmp64 = cpu_to_be64(read->rd_offset);
4769 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
4770 	tmp = htonl(*maxcount);
4771 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
4772 
4773 	tmp = xdr_zero;
4774 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
4775 			       xdr_pad_size(*maxcount));
4776 	return nfs_ok;
4777 }
4778 
4779 static __be32
4780 nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
4781 			    struct nfsd4_read *read,
4782 			    unsigned long *maxcount, u32 *eof)
4783 {
4784 	struct file *file = read->rd_nf->nf_file;
4785 	loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
4786 	loff_t f_size = i_size_read(file_inode(file));
4787 	unsigned long count;
4788 	__be32 *p;
4789 
4790 	if (data_pos == -ENXIO)
4791 		data_pos = f_size;
4792 	else if (data_pos <= read->rd_offset || (data_pos < f_size && data_pos % PAGE_SIZE))
4793 		return nfsd4_encode_read_plus_data(resp, read, maxcount, eof, &f_size);
4794 	count = data_pos - read->rd_offset;
4795 
4796 	/* Content type, offset, byte count */
4797 	p = xdr_reserve_space(resp->xdr, 4 + 8 + 8);
4798 	if (!p)
4799 		return nfserr_resource;
4800 
4801 	*p++ = htonl(NFS4_CONTENT_HOLE);
4802 	p = xdr_encode_hyper(p, read->rd_offset);
4803 	p = xdr_encode_hyper(p, count);
4804 
4805 	*eof = (read->rd_offset + count) >= f_size;
4806 	*maxcount = min_t(unsigned long, count, *maxcount);
4807 	return nfs_ok;
4808 }
4809 
4810 static __be32
4811 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
4812 		       struct nfsd4_read *read)
4813 {
4814 	unsigned long maxcount, count;
4815 	struct xdr_stream *xdr = resp->xdr;
4816 	struct file *file;
4817 	int starting_len = xdr->buf->len;
4818 	int last_segment = xdr->buf->len;
4819 	int segments = 0;
4820 	__be32 *p, tmp;
4821 	bool is_data;
4822 	loff_t pos;
4823 	u32 eof;
4824 
4825 	if (nfserr)
4826 		return nfserr;
4827 	file = read->rd_nf->nf_file;
4828 
4829 	/* eof flag, segment count */
4830 	p = xdr_reserve_space(xdr, 4 + 4);
4831 	if (!p)
4832 		return nfserr_resource;
4833 	xdr_commit_encode(xdr);
4834 
4835 	maxcount = min_t(unsigned long, read->rd_length,
4836 			 (xdr->buf->buflen - xdr->buf->len));
4837 	count    = maxcount;
4838 
4839 	eof = read->rd_offset >= i_size_read(file_inode(file));
4840 	if (eof)
4841 		goto out;
4842 
4843 	pos = vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4844 	is_data = pos > read->rd_offset;
4845 
4846 	while (count > 0 && !eof) {
4847 		maxcount = count;
4848 		if (is_data)
4849 			nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof,
4850 						segments == 0 ? &pos : NULL);
4851 		else
4852 			nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
4853 		if (nfserr)
4854 			goto out;
4855 		count -= maxcount;
4856 		read->rd_offset += maxcount;
4857 		is_data = !is_data;
4858 		last_segment = xdr->buf->len;
4859 		segments++;
4860 	}
4861 
4862 out:
4863 	if (nfserr && segments == 0)
4864 		xdr_truncate_encode(xdr, starting_len);
4865 	else {
4866 		if (nfserr) {
4867 			xdr_truncate_encode(xdr, last_segment);
4868 			nfserr = nfs_ok;
4869 			eof = 0;
4870 		}
4871 		tmp = htonl(eof);
4872 		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
4873 		tmp = htonl(segments);
4874 		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
4875 	}
4876 
4877 	return nfserr;
4878 }
4879 
4880 static __be32
4881 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
4882 			 struct nfsd4_copy_notify *cn)
4883 {
4884 	struct xdr_stream *xdr = resp->xdr;
4885 	__be32 *p;
4886 
4887 	if (nfserr)
4888 		return nfserr;
4889 
4890 	/* 8 sec, 4 nsec */
4891 	p = xdr_reserve_space(xdr, 12);
4892 	if (!p)
4893 		return nfserr_resource;
4894 
4895 	/* cnr_lease_time */
4896 	p = xdr_encode_hyper(p, cn->cpn_sec);
4897 	*p++ = cpu_to_be32(cn->cpn_nsec);
4898 
4899 	/* cnr_stateid */
4900 	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
4901 	if (nfserr)
4902 		return nfserr;
4903 
4904 	/* cnr_src.nl_nsvr */
4905 	p = xdr_reserve_space(xdr, 4);
4906 	if (!p)
4907 		return nfserr_resource;
4908 
4909 	*p++ = cpu_to_be32(1);
4910 
4911 	nfserr = nfsd42_encode_nl4_server(resp, cn->cpn_src);
4912 	return nfserr;
4913 }
4914 
4915 static __be32
4916 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
4917 		  struct nfsd4_seek *seek)
4918 {
4919 	__be32 *p;
4920 
4921 	p = xdr_reserve_space(resp->xdr, 4 + 8);
4922 	*p++ = cpu_to_be32(seek->seek_eof);
4923 	p = xdr_encode_hyper(p, seek->seek_pos);
4924 
4925 	return 0;
4926 }
4927 
4928 static __be32
4929 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
4930 {
4931 	return nfserr;
4932 }
4933 
4934 /*
4935  * Encode kmalloc-ed buffer in to XDR stream.
4936  */
4937 static __be32
4938 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
4939 {
4940 	u32 cplen;
4941 	__be32 *p;
4942 
4943 	cplen = min_t(unsigned long, buflen,
4944 		      ((void *)xdr->end - (void *)xdr->p));
4945 	p = xdr_reserve_space(xdr, cplen);
4946 	if (!p)
4947 		return nfserr_resource;
4948 
4949 	memcpy(p, buf, cplen);
4950 	buf += cplen;
4951 	buflen -= cplen;
4952 
4953 	while (buflen) {
4954 		cplen = min_t(u32, buflen, PAGE_SIZE);
4955 		p = xdr_reserve_space(xdr, cplen);
4956 		if (!p)
4957 			return nfserr_resource;
4958 
4959 		memcpy(p, buf, cplen);
4960 
4961 		if (cplen < PAGE_SIZE) {
4962 			/*
4963 			 * We're done, with a length that wasn't page
4964 			 * aligned, so possibly not word aligned. Pad
4965 			 * any trailing bytes with 0.
4966 			 */
4967 			xdr_encode_opaque_fixed(p, NULL, cplen);
4968 			break;
4969 		}
4970 
4971 		buflen -= PAGE_SIZE;
4972 		buf += PAGE_SIZE;
4973 	}
4974 
4975 	return 0;
4976 }
4977 
4978 static __be32
4979 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4980 		      struct nfsd4_getxattr *getxattr)
4981 {
4982 	struct xdr_stream *xdr = resp->xdr;
4983 	__be32 *p, err;
4984 
4985 	p = xdr_reserve_space(xdr, 4);
4986 	if (!p)
4987 		return nfserr_resource;
4988 
4989 	*p = cpu_to_be32(getxattr->getxa_len);
4990 
4991 	if (getxattr->getxa_len == 0)
4992 		return 0;
4993 
4994 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
4995 				    getxattr->getxa_len);
4996 
4997 	kvfree(getxattr->getxa_buf);
4998 
4999 	return err;
5000 }
5001 
5002 static __be32
5003 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5004 		      struct nfsd4_setxattr *setxattr)
5005 {
5006 	struct xdr_stream *xdr = resp->xdr;
5007 	__be32 *p;
5008 
5009 	p = xdr_reserve_space(xdr, 20);
5010 	if (!p)
5011 		return nfserr_resource;
5012 
5013 	encode_cinfo(p, &setxattr->setxa_cinfo);
5014 
5015 	return 0;
5016 }
5017 
5018 /*
5019  * See if there are cookie values that can be rejected outright.
5020  */
5021 static __be32
5022 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5023 				u32 *offsetp)
5024 {
5025 	u64 cookie = listxattrs->lsxa_cookie;
5026 
5027 	/*
5028 	 * If the cookie is larger than the maximum number we can fit
5029 	 * in either the buffer we just got back from vfs_listxattr, or,
5030 	 * XDR-encoded, in the return buffer, it's invalid.
5031 	 */
5032 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5033 		return nfserr_badcookie;
5034 
5035 	if (cookie > (listxattrs->lsxa_maxcount /
5036 		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
5037 		return nfserr_badcookie;
5038 
5039 	*offsetp = (u32)cookie;
5040 	return 0;
5041 }
5042 
5043 static __be32
5044 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5045 			struct nfsd4_listxattrs *listxattrs)
5046 {
5047 	struct xdr_stream *xdr = resp->xdr;
5048 	u32 cookie_offset, count_offset, eof;
5049 	u32 left, xdrleft, slen, count;
5050 	u32 xdrlen, offset;
5051 	u64 cookie;
5052 	char *sp;
5053 	__be32 status, tmp;
5054 	__be32 *p;
5055 	u32 nuser;
5056 
5057 	eof = 1;
5058 
5059 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5060 	if (status)
5061 		goto out;
5062 
5063 	/*
5064 	 * Reserve space for the cookie and the name array count. Record
5065 	 * the offsets to save them later.
5066 	 */
5067 	cookie_offset = xdr->buf->len;
5068 	count_offset = cookie_offset + 8;
5069 	p = xdr_reserve_space(xdr, 12);
5070 	if (!p) {
5071 		status = nfserr_resource;
5072 		goto out;
5073 	}
5074 
5075 	count = 0;
5076 	left = listxattrs->lsxa_len;
5077 	sp = listxattrs->lsxa_buf;
5078 	nuser = 0;
5079 
5080 	xdrleft = listxattrs->lsxa_maxcount;
5081 
5082 	while (left > 0 && xdrleft > 0) {
5083 		slen = strlen(sp);
5084 
5085 		/*
5086 		 * Check if this is a "user." attribute, skip it if not.
5087 		 */
5088 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5089 			goto contloop;
5090 
5091 		slen -= XATTR_USER_PREFIX_LEN;
5092 		xdrlen = 4 + ((slen + 3) & ~3);
5093 		if (xdrlen > xdrleft) {
5094 			if (count == 0) {
5095 				/*
5096 				 * Can't even fit the first attribute name.
5097 				 */
5098 				status = nfserr_toosmall;
5099 				goto out;
5100 			}
5101 			eof = 0;
5102 			goto wreof;
5103 		}
5104 
5105 		left -= XATTR_USER_PREFIX_LEN;
5106 		sp += XATTR_USER_PREFIX_LEN;
5107 		if (nuser++ < offset)
5108 			goto contloop;
5109 
5110 
5111 		p = xdr_reserve_space(xdr, xdrlen);
5112 		if (!p) {
5113 			status = nfserr_resource;
5114 			goto out;
5115 		}
5116 
5117 		xdr_encode_opaque(p, sp, slen);
5118 
5119 		xdrleft -= xdrlen;
5120 		count++;
5121 contloop:
5122 		sp += slen + 1;
5123 		left -= slen + 1;
5124 	}
5125 
5126 	/*
5127 	 * If there were user attributes to copy, but we didn't copy
5128 	 * any, the offset was too large (e.g. the cookie was invalid).
5129 	 */
5130 	if (nuser > 0 && count == 0) {
5131 		status = nfserr_badcookie;
5132 		goto out;
5133 	}
5134 
5135 wreof:
5136 	p = xdr_reserve_space(xdr, 4);
5137 	if (!p) {
5138 		status = nfserr_resource;
5139 		goto out;
5140 	}
5141 	*p = cpu_to_be32(eof);
5142 
5143 	cookie = offset + count;
5144 
5145 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
5146 	tmp = cpu_to_be32(count);
5147 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5148 out:
5149 	if (listxattrs->lsxa_len)
5150 		kvfree(listxattrs->lsxa_buf);
5151 	return status;
5152 }
5153 
5154 static __be32
5155 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5156 			 struct nfsd4_removexattr *removexattr)
5157 {
5158 	struct xdr_stream *xdr = resp->xdr;
5159 	__be32 *p;
5160 
5161 	p = xdr_reserve_space(xdr, 20);
5162 	if (!p)
5163 		return nfserr_resource;
5164 
5165 	p = encode_cinfo(p, &removexattr->rmxa_cinfo);
5166 	return 0;
5167 }
5168 
5169 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
5170 
5171 /*
5172  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5173  * since we don't need to filter out obsolete ops as this is
5174  * done in the decoding phase.
5175  */
5176 static const nfsd4_enc nfsd4_enc_ops[] = {
5177 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
5178 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
5179 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
5180 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
5181 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
5182 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5183 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
5184 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
5185 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
5186 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
5187 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
5188 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
5189 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
5190 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
5191 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5192 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
5193 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
5194 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
5195 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
5196 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5197 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
5198 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5199 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
5200 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
5201 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
5202 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
5203 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
5204 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
5205 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
5206 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
5207 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
5208 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
5209 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
5210 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
5211 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5212 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
5213 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
5214 
5215 	/* NFSv4.1 operations */
5216 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
5217 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
5218 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
5219 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
5220 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
5221 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
5222 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5223 #ifdef CONFIG_NFSD_PNFS
5224 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
5225 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5226 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
5227 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
5228 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
5229 #else
5230 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
5231 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5232 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
5233 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
5234 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5235 #endif
5236 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
5237 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
5238 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
5239 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
5240 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5241 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
5242 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
5243 
5244 	/* NFSv4.2 operations */
5245 	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5246 	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
5247 	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_copy_notify,
5248 	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5249 	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
5250 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
5251 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
5252 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
5253 	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
5254 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_read_plus,
5255 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
5256 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
5257 	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
5258 
5259 	/* RFC 8276 extended atributes operations */
5260 	[OP_GETXATTR]		= (nfsd4_enc)nfsd4_encode_getxattr,
5261 	[OP_SETXATTR]		= (nfsd4_enc)nfsd4_encode_setxattr,
5262 	[OP_LISTXATTRS]		= (nfsd4_enc)nfsd4_encode_listxattrs,
5263 	[OP_REMOVEXATTR]	= (nfsd4_enc)nfsd4_encode_removexattr,
5264 };
5265 
5266 /*
5267  * Calculate whether we still have space to encode repsize bytes.
5268  * There are two considerations:
5269  *     - For NFS versions >=4.1, the size of the reply must stay within
5270  *       session limits
5271  *     - For all NFS versions, we must stay within limited preallocated
5272  *       buffer space.
5273  *
5274  * This is called before the operation is processed, so can only provide
5275  * an upper estimate.  For some nonidempotent operations (such as
5276  * getattr), it's not necessarily a problem if that estimate is wrong,
5277  * as we can fail it after processing without significant side effects.
5278  */
5279 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5280 {
5281 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5282 	struct nfsd4_slot *slot = resp->cstate.slot;
5283 
5284 	if (buf->len + respsize <= buf->buflen)
5285 		return nfs_ok;
5286 	if (!nfsd4_has_session(&resp->cstate))
5287 		return nfserr_resource;
5288 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5289 		WARN_ON_ONCE(1);
5290 		return nfserr_rep_too_big_to_cache;
5291 	}
5292 	return nfserr_rep_too_big;
5293 }
5294 
5295 void
5296 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5297 {
5298 	struct xdr_stream *xdr = resp->xdr;
5299 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5300 	struct svc_rqst *rqstp = resp->rqstp;
5301 	const struct nfsd4_operation *opdesc = op->opdesc;
5302 	int post_err_offset;
5303 	nfsd4_enc encoder;
5304 	__be32 *p;
5305 
5306 	p = xdr_reserve_space(xdr, 8);
5307 	if (!p) {
5308 		WARN_ON_ONCE(1);
5309 		return;
5310 	}
5311 	*p++ = cpu_to_be32(op->opnum);
5312 	post_err_offset = xdr->buf->len;
5313 
5314 	if (op->opnum == OP_ILLEGAL)
5315 		goto status;
5316 	if (op->status && opdesc &&
5317 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5318 		goto status;
5319 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5320 	       !nfsd4_enc_ops[op->opnum]);
5321 	encoder = nfsd4_enc_ops[op->opnum];
5322 	op->status = encoder(resp, op->status, &op->u);
5323 	if (op->status)
5324 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5325 	if (opdesc && opdesc->op_release)
5326 		opdesc->op_release(&op->u);
5327 	xdr_commit_encode(xdr);
5328 
5329 	/* nfsd4_check_resp_size guarantees enough room for error status */
5330 	if (!op->status) {
5331 		int space_needed = 0;
5332 		if (!nfsd4_last_compound_op(rqstp))
5333 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5334 		op->status = nfsd4_check_resp_size(resp, space_needed);
5335 	}
5336 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5337 		struct nfsd4_slot *slot = resp->cstate.slot;
5338 
5339 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5340 			op->status = nfserr_rep_too_big_to_cache;
5341 		else
5342 			op->status = nfserr_rep_too_big;
5343 	}
5344 	if (op->status == nfserr_resource ||
5345 	    op->status == nfserr_rep_too_big ||
5346 	    op->status == nfserr_rep_too_big_to_cache) {
5347 		/*
5348 		 * The operation may have already been encoded or
5349 		 * partially encoded.  No op returns anything additional
5350 		 * in the case of one of these three errors, so we can
5351 		 * just truncate back to after the status.  But it's a
5352 		 * bug if we had to do this on a non-idempotent op:
5353 		 */
5354 		warn_on_nonidempotent_op(op);
5355 		xdr_truncate_encode(xdr, post_err_offset);
5356 	}
5357 	if (so) {
5358 		int len = xdr->buf->len - post_err_offset;
5359 
5360 		so->so_replay.rp_status = op->status;
5361 		so->so_replay.rp_buflen = len;
5362 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5363 						so->so_replay.rp_buf, len);
5364 	}
5365 status:
5366 	*p = op->status;
5367 }
5368 
5369 /*
5370  * Encode the reply stored in the stateowner reply cache
5371  *
5372  * XDR note: do not encode rp->rp_buflen: the buffer contains the
5373  * previously sent already encoded operation.
5374  */
5375 void
5376 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5377 {
5378 	__be32 *p;
5379 	struct nfs4_replay *rp = op->replay;
5380 
5381 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
5382 	if (!p) {
5383 		WARN_ON_ONCE(1);
5384 		return;
5385 	}
5386 	*p++ = cpu_to_be32(op->opnum);
5387 	*p++ = rp->rp_status;  /* already xdr'ed */
5388 
5389 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
5390 }
5391 
5392 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5393 {
5394 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5395 
5396 	if (args->ops != args->iops) {
5397 		kfree(args->ops);
5398 		args->ops = args->iops;
5399 	}
5400 	while (args->to_free) {
5401 		struct svcxdr_tmpbuf *tb = args->to_free;
5402 		args->to_free = tb->next;
5403 		kfree(tb);
5404 	}
5405 }
5406 
5407 bool
5408 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5409 {
5410 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5411 
5412 	/* svcxdr_tmp_alloc */
5413 	args->to_free = NULL;
5414 
5415 	args->xdr = xdr;
5416 	args->ops = args->iops;
5417 	args->rqstp = rqstp;
5418 
5419 	return nfsd4_decode_compound(args);
5420 }
5421 
5422 bool
5423 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5424 {
5425 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5426 	struct xdr_buf *buf = xdr->buf;
5427 	__be32 *p;
5428 
5429 	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
5430 				 buf->tail[0].iov_len);
5431 
5432 	/*
5433 	 * Send buffer space for the following items is reserved
5434 	 * at the top of nfsd4_proc_compound().
5435 	 */
5436 	p = resp->statusp;
5437 
5438 	*p++ = resp->cstate.status;
5439 
5440 	rqstp->rq_next_page = xdr->page_ptr + 1;
5441 
5442 	*p++ = htonl(resp->taglen);
5443 	memcpy(p, resp->tag, resp->taglen);
5444 	p += XDR_QUADLEN(resp->taglen);
5445 	*p++ = htonl(resp->opcnt);
5446 
5447 	nfsd4_sequence_done(resp);
5448 	return true;
5449 }
5450