xref: /openbmc/linux/fs/nfsd/nfs4xdr.c (revision 56edb6c2)
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_MODIFY_SET) {
474 		u32 set_it;
475 
476 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
477 			return nfserr_bad_xdr;
478 		switch (set_it) {
479 		case NFS4_SET_TO_CLIENT_TIME:
480 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
481 			if (status)
482 				return status;
483 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
484 			break;
485 		case NFS4_SET_TO_SERVER_TIME:
486 			iattr->ia_valid |= ATTR_MTIME;
487 			break;
488 		default:
489 			return nfserr_bad_xdr;
490 		}
491 	}
492 	label->len = 0;
493 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
494 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
495 		status = nfsd4_decode_security_label(argp, label);
496 		if (status)
497 			return status;
498 	}
499 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
500 		u32 mode, mask;
501 
502 		if (!umask)
503 			return nfserr_bad_xdr;
504 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
505 			return nfserr_bad_xdr;
506 		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
507 		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
508 			return nfserr_bad_xdr;
509 		*umask = mask & S_IRWXUGO;
510 		iattr->ia_valid |= ATTR_MODE;
511 	}
512 
513 	/* request sanity: did attrlist4 contain the expected number of words? */
514 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
515 		return nfserr_bad_xdr;
516 
517 	return nfs_ok;
518 }
519 
520 static __be32
521 nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
522 {
523 	__be32 *p;
524 
525 	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
526 	if (!p)
527 		return nfserr_bad_xdr;
528 	sid->si_generation = be32_to_cpup(p++);
529 	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
530 	return nfs_ok;
531 }
532 
533 static __be32
534 nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
535 {
536 	__be32 *p;
537 
538 	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
539 	if (!p)
540 		return nfserr_bad_xdr;
541 	memcpy(clientid, p, sizeof(*clientid));
542 	return nfs_ok;
543 }
544 
545 static __be32
546 nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
547 			  clientid_t *clientid, struct xdr_netobj *owner)
548 {
549 	__be32 status;
550 
551 	status = nfsd4_decode_clientid4(argp, clientid);
552 	if (status)
553 		return status;
554 	return nfsd4_decode_opaque(argp, owner);
555 }
556 
557 #ifdef CONFIG_NFSD_PNFS
558 static __be32
559 nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
560 		       struct nfsd4_deviceid *devid)
561 {
562 	__be32 *p;
563 
564 	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
565 	if (!p)
566 		return nfserr_bad_xdr;
567 	memcpy(devid, p, sizeof(*devid));
568 	return nfs_ok;
569 }
570 
571 static __be32
572 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
573 			   struct nfsd4_layoutcommit *lcp)
574 {
575 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
576 		return nfserr_bad_xdr;
577 	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
578 		return nfserr_bad_xdr;
579 	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
580 		return nfserr_bad_xdr;
581 
582 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
583 		return nfserr_bad_xdr;
584 	if (lcp->lc_up_len > 0) {
585 		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
586 		if (!lcp->lc_up_layout)
587 			return nfserr_bad_xdr;
588 	}
589 
590 	return nfs_ok;
591 }
592 
593 static __be32
594 nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
595 			   struct nfsd4_layoutreturn *lrp)
596 {
597 	__be32 status;
598 
599 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
600 		return nfserr_bad_xdr;
601 	switch (lrp->lr_return_type) {
602 	case RETURN_FILE:
603 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
604 			return nfserr_bad_xdr;
605 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
606 			return nfserr_bad_xdr;
607 		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
608 		if (status)
609 			return status;
610 		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
611 			return nfserr_bad_xdr;
612 		if (lrp->lrf_body_len > 0) {
613 			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
614 			if (!lrp->lrf_body)
615 				return nfserr_bad_xdr;
616 		}
617 		break;
618 	case RETURN_FSID:
619 	case RETURN_ALL:
620 		lrp->lr_seg.offset = 0;
621 		lrp->lr_seg.length = NFS4_MAX_UINT64;
622 		break;
623 	default:
624 		return nfserr_bad_xdr;
625 	}
626 
627 	return nfs_ok;
628 }
629 
630 #endif /* CONFIG_NFSD_PNFS */
631 
632 static __be32
633 nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
634 			struct nfs4_sessionid *sessionid)
635 {
636 	__be32 *p;
637 
638 	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
639 	if (!p)
640 		return nfserr_bad_xdr;
641 	memcpy(sessionid->data, p, sizeof(sessionid->data));
642 	return nfs_ok;
643 }
644 
645 /* Defined in Appendix A of RFC 5531 */
646 static __be32
647 nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
648 			   struct nfsd4_cb_sec *cbs)
649 {
650 	u32 stamp, gidcount, uid, gid;
651 	__be32 *p, status;
652 
653 	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
654 		return nfserr_bad_xdr;
655 	/* machine name */
656 	status = nfsd4_decode_ignored_string(argp, 255);
657 	if (status)
658 		return status;
659 	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
660 		return nfserr_bad_xdr;
661 	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
662 		return nfserr_bad_xdr;
663 	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
664 		return nfserr_bad_xdr;
665 	if (gidcount > 16)
666 		return nfserr_bad_xdr;
667 	p = xdr_inline_decode(argp->xdr, gidcount << 2);
668 	if (!p)
669 		return nfserr_bad_xdr;
670 	if (cbs->flavor == (u32)(-1)) {
671 		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
672 
673 		kuid_t kuid = make_kuid(userns, uid);
674 		kgid_t kgid = make_kgid(userns, gid);
675 		if (uid_valid(kuid) && gid_valid(kgid)) {
676 			cbs->uid = kuid;
677 			cbs->gid = kgid;
678 			cbs->flavor = RPC_AUTH_UNIX;
679 		} else {
680 			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
681 		}
682 	}
683 
684 	return nfs_ok;
685 }
686 
687 static __be32
688 nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
689 			     struct nfsd4_cb_sec *cbs)
690 {
691 	__be32 status;
692 	u32 service;
693 
694 	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
695 
696 	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
697 		return nfserr_bad_xdr;
698 	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
699 		return nfserr_bad_xdr;
700 	/* gcbp_handle_from_server */
701 	status = nfsd4_decode_ignored_string(argp, 0);
702 	if (status)
703 		return status;
704 	/* gcbp_handle_from_client */
705 	status = nfsd4_decode_ignored_string(argp, 0);
706 	if (status)
707 		return status;
708 
709 	return nfs_ok;
710 }
711 
712 /* a counted array of callback_sec_parms4 items */
713 static __be32
714 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
715 {
716 	u32 i, secflavor, nr_secflavs;
717 	__be32 status;
718 
719 	/* callback_sec_params4 */
720 	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
721 		return nfserr_bad_xdr;
722 	if (nr_secflavs)
723 		cbs->flavor = (u32)(-1);
724 	else
725 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
726 		cbs->flavor = 0;
727 
728 	for (i = 0; i < nr_secflavs; ++i) {
729 		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
730 			return nfserr_bad_xdr;
731 		switch (secflavor) {
732 		case RPC_AUTH_NULL:
733 			/* void */
734 			if (cbs->flavor == (u32)(-1))
735 				cbs->flavor = RPC_AUTH_NULL;
736 			break;
737 		case RPC_AUTH_UNIX:
738 			status = nfsd4_decode_authsys_parms(argp, cbs);
739 			if (status)
740 				return status;
741 			break;
742 		case RPC_AUTH_GSS:
743 			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
744 			if (status)
745 				return status;
746 			break;
747 		default:
748 			return nfserr_inval;
749 		}
750 	}
751 
752 	return nfs_ok;
753 }
754 
755 
756 /*
757  * NFSv4 operation argument decoders
758  */
759 
760 static __be32
761 nfsd4_decode_access(struct nfsd4_compoundargs *argp,
762 		    struct nfsd4_access *access)
763 {
764 	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
765 		return nfserr_bad_xdr;
766 	return nfs_ok;
767 }
768 
769 static __be32
770 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
771 {
772 	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
773 		return nfserr_bad_xdr;
774 	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
775 }
776 
777 
778 static __be32
779 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
780 {
781 	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
782 		return nfserr_bad_xdr;
783 	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
784 		return nfserr_bad_xdr;
785 	return nfs_ok;
786 }
787 
788 static __be32
789 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
790 {
791 	__be32 *p, status;
792 
793 	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
794 		return nfserr_bad_xdr;
795 	switch (create->cr_type) {
796 	case NF4LNK:
797 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
798 			return nfserr_bad_xdr;
799 		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
800 		if (!p)
801 			return nfserr_bad_xdr;
802 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
803 		if (!create->cr_data)
804 			return nfserr_jukebox;
805 		break;
806 	case NF4BLK:
807 	case NF4CHR:
808 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
809 			return nfserr_bad_xdr;
810 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
811 			return nfserr_bad_xdr;
812 		break;
813 	case NF4SOCK:
814 	case NF4FIFO:
815 	case NF4DIR:
816 	default:
817 		break;
818 	}
819 	status = nfsd4_decode_component4(argp, &create->cr_name,
820 					 &create->cr_namelen);
821 	if (status)
822 		return status;
823 	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
824 				    ARRAY_SIZE(create->cr_bmval),
825 				    &create->cr_iattr, &create->cr_acl,
826 				    &create->cr_label, &create->cr_umask);
827 	if (status)
828 		return status;
829 
830 	return nfs_ok;
831 }
832 
833 static inline __be32
834 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
835 {
836 	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
837 }
838 
839 static inline __be32
840 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
841 {
842 	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
843 				    ARRAY_SIZE(getattr->ga_bmval));
844 }
845 
846 static __be32
847 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
848 {
849 	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
850 }
851 
852 static __be32
853 nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
854 				 struct nfsd4_lock *lock)
855 {
856 	__be32 status;
857 
858 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
859 		return nfserr_bad_xdr;
860 	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
861 	if (status)
862 		return status;
863 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
864 		return nfserr_bad_xdr;
865 	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
866 					 &lock->lk_new_owner);
867 }
868 
869 static __be32
870 nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
871 			       struct nfsd4_lock *lock)
872 {
873 	__be32 status;
874 
875 	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
876 	if (status)
877 		return status;
878 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
879 		return nfserr_bad_xdr;
880 
881 	return nfs_ok;
882 }
883 
884 static __be32
885 nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
886 {
887 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
888 		return nfserr_bad_xdr;
889 	if (lock->lk_is_new)
890 		return nfsd4_decode_open_to_lock_owner4(argp, lock);
891 	return nfsd4_decode_exist_lock_owner4(argp, lock);
892 }
893 
894 static __be32
895 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
896 {
897 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
898 		return nfserr_bad_xdr;
899 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
900 		return nfserr_bad_xdr;
901 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
902 		return nfserr_bad_xdr;
903 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
904 		return nfserr_bad_xdr;
905 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
906 		return nfserr_bad_xdr;
907 	return nfsd4_decode_locker4(argp, lock);
908 }
909 
910 static __be32
911 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
912 {
913 	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
914 		return nfserr_bad_xdr;
915 	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
916 		return nfserr_bad_xdr;
917 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
918 		return nfserr_bad_xdr;
919 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
920 		return nfserr_bad_xdr;
921 	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
922 					 &lockt->lt_owner);
923 }
924 
925 static __be32
926 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
927 {
928 	__be32 status;
929 
930 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
931 		return nfserr_bad_xdr;
932 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
933 		return nfserr_bad_xdr;
934 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
935 		return nfserr_bad_xdr;
936 	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
937 	if (status)
938 		return status;
939 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
940 		return nfserr_bad_xdr;
941 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
942 		return nfserr_bad_xdr;
943 
944 	return nfs_ok;
945 }
946 
947 static __be32
948 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
949 {
950 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
951 }
952 
953 static __be32
954 nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
955 {
956 	__be32 status;
957 
958 	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
959 		return nfserr_bad_xdr;
960 	switch (open->op_createmode) {
961 	case NFS4_CREATE_UNCHECKED:
962 	case NFS4_CREATE_GUARDED:
963 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
964 					     ARRAY_SIZE(open->op_bmval),
965 					     &open->op_iattr, &open->op_acl,
966 					     &open->op_label, &open->op_umask);
967 		if (status)
968 			return status;
969 		break;
970 	case NFS4_CREATE_EXCLUSIVE:
971 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
972 		if (status)
973 			return status;
974 		break;
975 	case NFS4_CREATE_EXCLUSIVE4_1:
976 		if (argp->minorversion < 1)
977 			return nfserr_bad_xdr;
978 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
979 		if (status)
980 			return status;
981 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
982 					     ARRAY_SIZE(open->op_bmval),
983 					     &open->op_iattr, &open->op_acl,
984 					     &open->op_label, &open->op_umask);
985 		if (status)
986 			return status;
987 		break;
988 	default:
989 		return nfserr_bad_xdr;
990 	}
991 
992 	return nfs_ok;
993 }
994 
995 static __be32
996 nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
997 {
998 	__be32 status;
999 
1000 	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
1001 		return nfserr_bad_xdr;
1002 	switch (open->op_create) {
1003 	case NFS4_OPEN_NOCREATE:
1004 		break;
1005 	case NFS4_OPEN_CREATE:
1006 		status = nfsd4_decode_createhow4(argp, open);
1007 		if (status)
1008 			return status;
1009 		break;
1010 	default:
1011 		return nfserr_bad_xdr;
1012 	}
1013 
1014 	return nfs_ok;
1015 }
1016 
1017 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
1018 {
1019 	u32 w;
1020 
1021 	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
1022 		return nfserr_bad_xdr;
1023 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
1024 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
1025 	if (deleg_when)
1026 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
1027 
1028 	switch (w & NFS4_SHARE_ACCESS_MASK) {
1029 	case NFS4_SHARE_ACCESS_READ:
1030 	case NFS4_SHARE_ACCESS_WRITE:
1031 	case NFS4_SHARE_ACCESS_BOTH:
1032 		break;
1033 	default:
1034 		return nfserr_bad_xdr;
1035 	}
1036 	w &= ~NFS4_SHARE_ACCESS_MASK;
1037 	if (!w)
1038 		return nfs_ok;
1039 	if (!argp->minorversion)
1040 		return nfserr_bad_xdr;
1041 	switch (w & NFS4_SHARE_WANT_MASK) {
1042 	case NFS4_SHARE_WANT_NO_PREFERENCE:
1043 	case NFS4_SHARE_WANT_READ_DELEG:
1044 	case NFS4_SHARE_WANT_WRITE_DELEG:
1045 	case NFS4_SHARE_WANT_ANY_DELEG:
1046 	case NFS4_SHARE_WANT_NO_DELEG:
1047 	case NFS4_SHARE_WANT_CANCEL:
1048 		break;
1049 	default:
1050 		return nfserr_bad_xdr;
1051 	}
1052 	w &= ~NFS4_SHARE_WANT_MASK;
1053 	if (!w)
1054 		return nfs_ok;
1055 
1056 	if (!deleg_when)	/* open_downgrade */
1057 		return nfserr_inval;
1058 	switch (w) {
1059 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
1060 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
1061 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
1062 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
1063 		return nfs_ok;
1064 	}
1065 	return nfserr_bad_xdr;
1066 }
1067 
1068 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
1069 {
1070 	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
1071 		return nfserr_bad_xdr;
1072 	/* Note: unlike access bits, deny bits may be zero. */
1073 	if (*x & ~NFS4_SHARE_DENY_BOTH)
1074 		return nfserr_bad_xdr;
1075 
1076 	return nfs_ok;
1077 }
1078 
1079 static __be32
1080 nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
1081 			 struct nfsd4_open *open)
1082 {
1083 	__be32 status;
1084 
1085 	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
1086 		return nfserr_bad_xdr;
1087 	switch (open->op_claim_type) {
1088 	case NFS4_OPEN_CLAIM_NULL:
1089 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
1090 		status = nfsd4_decode_component4(argp, &open->op_fname,
1091 						 &open->op_fnamelen);
1092 		if (status)
1093 			return status;
1094 		break;
1095 	case NFS4_OPEN_CLAIM_PREVIOUS:
1096 		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
1097 			return nfserr_bad_xdr;
1098 		break;
1099 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
1100 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1101 		if (status)
1102 			return status;
1103 		status = nfsd4_decode_component4(argp, &open->op_fname,
1104 						 &open->op_fnamelen);
1105 		if (status)
1106 			return status;
1107 		break;
1108 	case NFS4_OPEN_CLAIM_FH:
1109 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1110 		if (argp->minorversion < 1)
1111 			return nfserr_bad_xdr;
1112 		/* void */
1113 		break;
1114 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1115 		if (argp->minorversion < 1)
1116 			return nfserr_bad_xdr;
1117 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1118 		if (status)
1119 			return status;
1120 		break;
1121 	default:
1122 		return nfserr_bad_xdr;
1123 	}
1124 
1125 	return nfs_ok;
1126 }
1127 
1128 static __be32
1129 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1130 {
1131 	__be32 status;
1132 	u32 dummy;
1133 
1134 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
1135 	open->op_iattr.ia_valid = 0;
1136 	open->op_openowner = NULL;
1137 
1138 	open->op_xdr_error = 0;
1139 	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
1140 		return nfserr_bad_xdr;
1141 	/* deleg_want is ignored */
1142 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
1143 					   &open->op_deleg_want, &dummy);
1144 	if (status)
1145 		return status;
1146 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
1147 	if (status)
1148 		return status;
1149 	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
1150 					   &open->op_owner);
1151 	if (status)
1152 		return status;
1153 	status = nfsd4_decode_openflag4(argp, open);
1154 	if (status)
1155 		return status;
1156 	return nfsd4_decode_open_claim4(argp, open);
1157 }
1158 
1159 static __be32
1160 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
1161 {
1162 	__be32 status;
1163 
1164 	if (argp->minorversion >= 1)
1165 		return nfserr_notsupp;
1166 
1167 	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
1168 	if (status)
1169 		return status;
1170 	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
1171 		return nfserr_bad_xdr;
1172 
1173 	return nfs_ok;
1174 }
1175 
1176 static __be32
1177 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
1178 {
1179 	__be32 status;
1180 
1181 	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
1182 	if (status)
1183 		return status;
1184 	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
1185 		return nfserr_bad_xdr;
1186 	/* deleg_want is ignored */
1187 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1188 					   &open_down->od_deleg_want, NULL);
1189 	if (status)
1190 		return status;
1191 	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1192 }
1193 
1194 static __be32
1195 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
1196 {
1197 	__be32 *p;
1198 
1199 	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
1200 		return nfserr_bad_xdr;
1201 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1202 		return nfserr_bad_xdr;
1203 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
1204 	if (!p)
1205 		return nfserr_bad_xdr;
1206 	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
1207 	if (!putfh->pf_fhval)
1208 		return nfserr_jukebox;
1209 
1210 	return nfs_ok;
1211 }
1212 
1213 static __be32
1214 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
1215 {
1216 	if (argp->minorversion == 0)
1217 		return nfs_ok;
1218 	return nfserr_notsupp;
1219 }
1220 
1221 static __be32
1222 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
1223 {
1224 	__be32 status;
1225 
1226 	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
1227 	if (status)
1228 		return status;
1229 	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
1230 		return nfserr_bad_xdr;
1231 	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
1232 		return nfserr_bad_xdr;
1233 
1234 	return nfs_ok;
1235 }
1236 
1237 static __be32
1238 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
1239 {
1240 	__be32 status;
1241 
1242 	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
1243 		return nfserr_bad_xdr;
1244 	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
1245 	if (status)
1246 		return status;
1247 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
1248 		return nfserr_bad_xdr;
1249 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
1250 		return nfserr_bad_xdr;
1251 	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
1252 					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
1253 		return nfserr_bad_xdr;
1254 
1255 	return nfs_ok;
1256 }
1257 
1258 static __be32
1259 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
1260 {
1261 	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
1262 }
1263 
1264 static __be32
1265 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
1266 {
1267 	__be32 status;
1268 
1269 	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
1270 	if (status)
1271 		return status;
1272 	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
1273 }
1274 
1275 static __be32
1276 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
1277 {
1278 	return nfsd4_decode_clientid4(argp, clientid);
1279 }
1280 
1281 static __be32
1282 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1283 		     struct nfsd4_secinfo *secinfo)
1284 {
1285 	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
1286 }
1287 
1288 static __be32
1289 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
1290 {
1291 	__be32 status;
1292 
1293 	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
1294 	if (status)
1295 		return status;
1296 	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
1297 				   ARRAY_SIZE(setattr->sa_bmval),
1298 				   &setattr->sa_iattr, &setattr->sa_acl,
1299 				   &setattr->sa_label, NULL);
1300 }
1301 
1302 static __be32
1303 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
1304 {
1305 	__be32 *p, status;
1306 
1307 	if (argp->minorversion >= 1)
1308 		return nfserr_notsupp;
1309 
1310 	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
1311 	if (status)
1312 		return status;
1313 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1314 	if (status)
1315 		return status;
1316 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
1317 		return nfserr_bad_xdr;
1318 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
1319 		return nfserr_bad_xdr;
1320 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
1321 	if (!p)
1322 		return nfserr_bad_xdr;
1323 	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
1324 						setclientid->se_callback_netid_len);
1325 	if (!setclientid->se_callback_netid_val)
1326 		return nfserr_jukebox;
1327 
1328 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
1329 		return nfserr_bad_xdr;
1330 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
1331 	if (!p)
1332 		return nfserr_bad_xdr;
1333 	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
1334 						setclientid->se_callback_addr_len);
1335 	if (!setclientid->se_callback_addr_val)
1336 		return nfserr_jukebox;
1337 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
1338 		return nfserr_bad_xdr;
1339 
1340 	return nfs_ok;
1341 }
1342 
1343 static __be32
1344 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1345 {
1346 	__be32 status;
1347 
1348 	if (argp->minorversion >= 1)
1349 		return nfserr_notsupp;
1350 
1351 	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
1352 	if (status)
1353 		return status;
1354 	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
1355 }
1356 
1357 /* Also used for NVERIFY */
1358 static __be32
1359 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1360 {
1361 	__be32 *p, status;
1362 
1363 	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
1364 				      ARRAY_SIZE(verify->ve_bmval));
1365 	if (status)
1366 		return status;
1367 
1368 	/* For convenience's sake, we compare raw xdr'd attributes in
1369 	 * nfsd4_proc_verify */
1370 
1371 	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
1372 		return nfserr_bad_xdr;
1373 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
1374 	if (!p)
1375 		return nfserr_bad_xdr;
1376 	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
1377 	if (!verify->ve_attrval)
1378 		return nfserr_jukebox;
1379 
1380 	return nfs_ok;
1381 }
1382 
1383 static __be32
1384 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1385 {
1386 	__be32 status;
1387 
1388 	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
1389 	if (status)
1390 		return status;
1391 	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
1392 		return nfserr_bad_xdr;
1393 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
1394 		return nfserr_bad_xdr;
1395 	if (write->wr_stable_how > NFS_FILE_SYNC)
1396 		return nfserr_bad_xdr;
1397 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
1398 		return nfserr_bad_xdr;
1399 	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
1400 		return nfserr_bad_xdr;
1401 
1402 	return nfs_ok;
1403 }
1404 
1405 static __be32
1406 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1407 {
1408 	__be32 status;
1409 
1410 	if (argp->minorversion >= 1)
1411 		return nfserr_notsupp;
1412 
1413 	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
1414 					   &rlockowner->rl_owner);
1415 	if (status)
1416 		return status;
1417 
1418 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1419 		return nfserr_inval;
1420 
1421 	return nfs_ok;
1422 }
1423 
1424 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
1425 {
1426 	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
1427 		return nfserr_bad_xdr;
1428 	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
1429 }
1430 
1431 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
1432 {
1433 	u32 use_conn_in_rdma_mode;
1434 	__be32 status;
1435 
1436 	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
1437 	if (status)
1438 		return status;
1439 	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
1440 		return nfserr_bad_xdr;
1441 	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
1442 		return nfserr_bad_xdr;
1443 
1444 	return nfs_ok;
1445 }
1446 
1447 static __be32
1448 nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
1449 			       struct nfsd4_exchange_id *exid)
1450 {
1451 	__be32 status;
1452 
1453 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
1454 				      ARRAY_SIZE(exid->spo_must_enforce));
1455 	if (status)
1456 		return nfserr_bad_xdr;
1457 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
1458 				      ARRAY_SIZE(exid->spo_must_allow));
1459 	if (status)
1460 		return nfserr_bad_xdr;
1461 
1462 	return nfs_ok;
1463 }
1464 
1465 /*
1466  * This implementation currently does not support SP4_SSV.
1467  * This decoder simply skips over these arguments.
1468  */
1469 static noinline __be32
1470 nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
1471 			  struct nfsd4_exchange_id *exid)
1472 {
1473 	u32 count, window, num_gss_handles;
1474 	__be32 status;
1475 
1476 	/* ssp_ops */
1477 	status = nfsd4_decode_state_protect_ops(argp, exid);
1478 	if (status)
1479 		return status;
1480 
1481 	/* ssp_hash_algs<> */
1482 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1483 		return nfserr_bad_xdr;
1484 	while (count--) {
1485 		status = nfsd4_decode_ignored_string(argp, 0);
1486 		if (status)
1487 			return status;
1488 	}
1489 
1490 	/* ssp_encr_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 	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
1500 		return nfserr_bad_xdr;
1501 	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
1502 		return nfserr_bad_xdr;
1503 
1504 	return nfs_ok;
1505 }
1506 
1507 static __be32
1508 nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
1509 			      struct nfsd4_exchange_id *exid)
1510 {
1511 	__be32 status;
1512 
1513 	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
1514 		return nfserr_bad_xdr;
1515 	switch (exid->spa_how) {
1516 	case SP4_NONE:
1517 		break;
1518 	case SP4_MACH_CRED:
1519 		status = nfsd4_decode_state_protect_ops(argp, exid);
1520 		if (status)
1521 			return status;
1522 		break;
1523 	case SP4_SSV:
1524 		status = nfsd4_decode_ssv_sp_parms(argp, exid);
1525 		if (status)
1526 			return status;
1527 		break;
1528 	default:
1529 		return nfserr_bad_xdr;
1530 	}
1531 
1532 	return nfs_ok;
1533 }
1534 
1535 static __be32
1536 nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
1537 			  struct nfsd4_exchange_id *exid)
1538 {
1539 	__be32 status;
1540 	u32 count;
1541 
1542 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1543 		return nfserr_bad_xdr;
1544 	switch (count) {
1545 	case 0:
1546 		break;
1547 	case 1:
1548 		/* Note that RFC 8881 places no length limit on
1549 		 * nii_domain, but this implementation permits no
1550 		 * more than NFS4_OPAQUE_LIMIT bytes */
1551 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1552 		if (status)
1553 			return status;
1554 		/* Note that RFC 8881 places no length limit on
1555 		 * nii_name, but this implementation permits no
1556 		 * more than NFS4_OPAQUE_LIMIT bytes */
1557 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1558 		if (status)
1559 			return status;
1560 		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
1561 		if (status)
1562 			return status;
1563 		break;
1564 	default:
1565 		return nfserr_bad_xdr;
1566 	}
1567 
1568 	return nfs_ok;
1569 }
1570 
1571 static __be32
1572 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1573 			 struct nfsd4_exchange_id *exid)
1574 {
1575 	__be32 status;
1576 
1577 	status = nfsd4_decode_verifier4(argp, &exid->verifier);
1578 	if (status)
1579 		return status;
1580 	status = nfsd4_decode_opaque(argp, &exid->clname);
1581 	if (status)
1582 		return status;
1583 	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
1584 		return nfserr_bad_xdr;
1585 	status = nfsd4_decode_state_protect4_a(argp, exid);
1586 	if (status)
1587 		return status;
1588 	return nfsd4_decode_nfs_impl_id4(argp, exid);
1589 }
1590 
1591 static __be32
1592 nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
1593 			    struct nfsd4_channel_attrs *ca)
1594 {
1595 	__be32 *p;
1596 
1597 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
1598 	if (!p)
1599 		return nfserr_bad_xdr;
1600 
1601 	/* headerpadsz is ignored */
1602 	p++;
1603 	ca->maxreq_sz = be32_to_cpup(p++);
1604 	ca->maxresp_sz = be32_to_cpup(p++);
1605 	ca->maxresp_cached = be32_to_cpup(p++);
1606 	ca->maxops = be32_to_cpup(p++);
1607 	ca->maxreqs = be32_to_cpup(p++);
1608 	ca->nr_rdma_attrs = be32_to_cpup(p);
1609 	switch (ca->nr_rdma_attrs) {
1610 	case 0:
1611 		break;
1612 	case 1:
1613 		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
1614 			return nfserr_bad_xdr;
1615 		break;
1616 	default:
1617 		return nfserr_bad_xdr;
1618 	}
1619 
1620 	return nfs_ok;
1621 }
1622 
1623 static __be32
1624 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1625 			    struct nfsd4_create_session *sess)
1626 {
1627 	__be32 status;
1628 
1629 	status = nfsd4_decode_clientid4(argp, &sess->clientid);
1630 	if (status)
1631 		return status;
1632 	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
1633 		return nfserr_bad_xdr;
1634 	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
1635 		return nfserr_bad_xdr;
1636 	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
1637 	if (status)
1638 		return status;
1639 	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
1640 	if (status)
1641 		return status;
1642 	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
1643 		return nfserr_bad_xdr;
1644 	status = nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1645 	if (status)
1646 		return status;
1647 
1648 	return nfs_ok;
1649 }
1650 
1651 static __be32
1652 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1653 			     struct nfsd4_destroy_session *destroy_session)
1654 {
1655 	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
1656 }
1657 
1658 static __be32
1659 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1660 			  struct nfsd4_free_stateid *free_stateid)
1661 {
1662 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
1663 }
1664 
1665 #ifdef CONFIG_NFSD_PNFS
1666 static __be32
1667 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1668 		struct nfsd4_getdeviceinfo *gdev)
1669 {
1670 	__be32 status;
1671 
1672 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1673 	if (status)
1674 		return status;
1675 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1676 		return nfserr_bad_xdr;
1677 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1678 		return nfserr_bad_xdr;
1679 	if (xdr_stream_decode_uint32_array(argp->xdr,
1680 					   &gdev->gd_notify_types, 1) < 0)
1681 		return nfserr_bad_xdr;
1682 
1683 	return nfs_ok;
1684 }
1685 
1686 static __be32
1687 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1688 			  struct nfsd4_layoutcommit *lcp)
1689 {
1690 	__be32 *p, status;
1691 
1692 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1693 		return nfserr_bad_xdr;
1694 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1695 		return nfserr_bad_xdr;
1696 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1697 		return nfserr_bad_xdr;
1698 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1699 	if (status)
1700 		return status;
1701 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1702 		return nfserr_bad_xdr;
1703 	if (lcp->lc_newoffset) {
1704 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1705 			return nfserr_bad_xdr;
1706 	} else
1707 		lcp->lc_last_wr = 0;
1708 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1709 	if (!p)
1710 		return nfserr_bad_xdr;
1711 	if (xdr_item_is_present(p)) {
1712 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1713 		if (status)
1714 			return status;
1715 	} else {
1716 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1717 	}
1718 	return nfsd4_decode_layoutupdate4(argp, lcp);
1719 }
1720 
1721 static __be32
1722 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1723 		struct nfsd4_layoutget *lgp)
1724 {
1725 	__be32 status;
1726 
1727 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1728 		return nfserr_bad_xdr;
1729 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1730 		return nfserr_bad_xdr;
1731 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1732 		return nfserr_bad_xdr;
1733 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1734 		return nfserr_bad_xdr;
1735 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1736 		return nfserr_bad_xdr;
1737 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1738 		return nfserr_bad_xdr;
1739 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1740 	if (status)
1741 		return status;
1742 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1743 		return nfserr_bad_xdr;
1744 
1745 	return nfs_ok;
1746 }
1747 
1748 static __be32
1749 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1750 		struct nfsd4_layoutreturn *lrp)
1751 {
1752 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1753 		return nfserr_bad_xdr;
1754 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1755 		return nfserr_bad_xdr;
1756 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1757 		return nfserr_bad_xdr;
1758 	return nfsd4_decode_layoutreturn4(argp, lrp);
1759 }
1760 #endif /* CONFIG_NFSD_PNFS */
1761 
1762 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1763 					   struct nfsd4_secinfo_no_name *sin)
1764 {
1765 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1766 		return nfserr_bad_xdr;
1767 	return nfs_ok;
1768 }
1769 
1770 static __be32
1771 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1772 		      struct nfsd4_sequence *seq)
1773 {
1774 	__be32 *p, status;
1775 
1776 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1777 	if (status)
1778 		return status;
1779 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1780 	if (!p)
1781 		return nfserr_bad_xdr;
1782 	seq->seqid = be32_to_cpup(p++);
1783 	seq->slotid = be32_to_cpup(p++);
1784 	seq->maxslots = be32_to_cpup(p++);
1785 	seq->cachethis = be32_to_cpup(p);
1786 
1787 	return nfs_ok;
1788 }
1789 
1790 static __be32
1791 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1792 {
1793 	struct nfsd4_test_stateid_id *stateid;
1794 	__be32 status;
1795 	u32 i;
1796 
1797 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1798 		return nfserr_bad_xdr;
1799 
1800 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1801 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1802 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1803 		if (!stateid)
1804 			return nfserrno(-ENOMEM);	/* XXX: not jukebox? */
1805 		INIT_LIST_HEAD(&stateid->ts_id_list);
1806 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1807 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1808 		if (status)
1809 			return status;
1810 	}
1811 
1812 	return nfs_ok;
1813 }
1814 
1815 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1816 					    struct nfsd4_destroy_clientid *dc)
1817 {
1818 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1819 }
1820 
1821 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1822 					    struct nfsd4_reclaim_complete *rc)
1823 {
1824 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1825 		return nfserr_bad_xdr;
1826 	return nfs_ok;
1827 }
1828 
1829 static __be32
1830 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1831 		       struct nfsd4_fallocate *fallocate)
1832 {
1833 	__be32 status;
1834 
1835 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1836 	if (status)
1837 		return status;
1838 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1839 		return nfserr_bad_xdr;
1840 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1841 		return nfserr_bad_xdr;
1842 
1843 	return nfs_ok;
1844 }
1845 
1846 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1847 				      struct nl4_server *ns)
1848 {
1849 	struct nfs42_netaddr *naddr;
1850 	__be32 *p;
1851 
1852 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1853 		return nfserr_bad_xdr;
1854 
1855 	/* currently support for 1 inter-server source server */
1856 	switch (ns->nl4_type) {
1857 	case NL4_NETADDR:
1858 		naddr = &ns->u.nl4_addr;
1859 
1860 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1861 			return nfserr_bad_xdr;
1862 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1863 			return nfserr_bad_xdr;
1864 
1865 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1866 		if (!p)
1867 			return nfserr_bad_xdr;
1868 		memcpy(naddr->netid, p, naddr->netid_len);
1869 
1870 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1871 			return nfserr_bad_xdr;
1872 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1873 			return nfserr_bad_xdr;
1874 
1875 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1876 		if (!p)
1877 			return nfserr_bad_xdr;
1878 		memcpy(naddr->addr, p, naddr->addr_len);
1879 		break;
1880 	default:
1881 		return nfserr_bad_xdr;
1882 	}
1883 
1884 	return nfs_ok;
1885 }
1886 
1887 static __be32
1888 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
1889 {
1890 	struct nl4_server *ns_dummy;
1891 	u32 consecutive, i, count;
1892 	__be32 status;
1893 
1894 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
1895 	if (status)
1896 		return status;
1897 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
1898 	if (status)
1899 		return status;
1900 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
1901 		return nfserr_bad_xdr;
1902 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
1903 		return nfserr_bad_xdr;
1904 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
1905 		return nfserr_bad_xdr;
1906 	/* ca_consecutive: we always do consecutive copies */
1907 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
1908 		return nfserr_bad_xdr;
1909 	if (xdr_stream_decode_u32(argp->xdr, &copy->cp_synchronous) < 0)
1910 		return nfserr_bad_xdr;
1911 
1912 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1913 		return nfserr_bad_xdr;
1914 	copy->cp_intra = false;
1915 	if (count == 0) { /* intra-server copy */
1916 		copy->cp_intra = true;
1917 		return nfs_ok;
1918 	}
1919 
1920 	/* decode all the supplied server addresses but use only the first */
1921 	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
1922 	if (status)
1923 		return status;
1924 
1925 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
1926 	if (ns_dummy == NULL)
1927 		return nfserrno(-ENOMEM);	/* XXX: jukebox? */
1928 	for (i = 0; i < count - 1; i++) {
1929 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
1930 		if (status) {
1931 			kfree(ns_dummy);
1932 			return status;
1933 		}
1934 	}
1935 	kfree(ns_dummy);
1936 
1937 	return nfs_ok;
1938 }
1939 
1940 static __be32
1941 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
1942 			 struct nfsd4_copy_notify *cn)
1943 {
1944 	__be32 status;
1945 
1946 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
1947 	if (status)
1948 		return status;
1949 	return nfsd4_decode_nl4_server(argp, &cn->cpn_dst);
1950 }
1951 
1952 static __be32
1953 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
1954 			    struct nfsd4_offload_status *os)
1955 {
1956 	return nfsd4_decode_stateid4(argp, &os->stateid);
1957 }
1958 
1959 static __be32
1960 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
1961 {
1962 	__be32 status;
1963 
1964 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
1965 	if (status)
1966 		return status;
1967 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
1968 		return nfserr_bad_xdr;
1969 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
1970 		return nfserr_bad_xdr;
1971 
1972 	return nfs_ok;
1973 }
1974 
1975 static __be32
1976 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
1977 {
1978 	__be32 status;
1979 
1980 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
1981 	if (status)
1982 		return status;
1983 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
1984 	if (status)
1985 		return status;
1986 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
1987 		return nfserr_bad_xdr;
1988 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
1989 		return nfserr_bad_xdr;
1990 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
1991 		return nfserr_bad_xdr;
1992 
1993 	return nfs_ok;
1994 }
1995 
1996 /*
1997  * XDR data that is more than PAGE_SIZE in size is normally part of a
1998  * read or write. However, the size of extended attributes is limited
1999  * by the maximum request size, and then further limited by the underlying
2000  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2001  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2002  * and we're not dealing with contiguous pages, we need to do some copying.
2003  */
2004 
2005 /*
2006  * Decode data into buffer.
2007  */
2008 static __be32
2009 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2010 		       char **bufp, u32 buflen)
2011 {
2012 	struct page **pages = xdr->pages;
2013 	struct kvec *head = xdr->head;
2014 	char *tmp, *dp;
2015 	u32 len;
2016 
2017 	if (buflen <= head->iov_len) {
2018 		/*
2019 		 * We're in luck, the head has enough space. Just return
2020 		 * the head, no need for copying.
2021 		 */
2022 		*bufp = head->iov_base;
2023 		return 0;
2024 	}
2025 
2026 	tmp = svcxdr_tmpalloc(argp, buflen);
2027 	if (tmp == NULL)
2028 		return nfserr_jukebox;
2029 
2030 	dp = tmp;
2031 	memcpy(dp, head->iov_base, head->iov_len);
2032 	buflen -= head->iov_len;
2033 	dp += head->iov_len;
2034 
2035 	while (buflen > 0) {
2036 		len = min_t(u32, buflen, PAGE_SIZE);
2037 		memcpy(dp, page_address(*pages), len);
2038 
2039 		buflen -= len;
2040 		dp += len;
2041 		pages++;
2042 	}
2043 
2044 	*bufp = tmp;
2045 	return 0;
2046 }
2047 
2048 /*
2049  * Get a user extended attribute name from the XDR buffer.
2050  * It will not have the "user." prefix, so prepend it.
2051  * Lastly, check for nul characters in the name.
2052  */
2053 static __be32
2054 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2055 {
2056 	char *name, *sp, *dp;
2057 	u32 namelen, cnt;
2058 	__be32 *p;
2059 
2060 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2061 		return nfserr_bad_xdr;
2062 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2063 		return nfserr_nametoolong;
2064 	if (namelen == 0)
2065 		return nfserr_bad_xdr;
2066 	p = xdr_inline_decode(argp->xdr, namelen);
2067 	if (!p)
2068 		return nfserr_bad_xdr;
2069 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2070 	if (!name)
2071 		return nfserr_jukebox;
2072 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2073 
2074 	/*
2075 	 * Copy the extended attribute name over while checking for 0
2076 	 * characters.
2077 	 */
2078 	sp = (char *)p;
2079 	dp = name + XATTR_USER_PREFIX_LEN;
2080 	cnt = namelen;
2081 
2082 	while (cnt-- > 0) {
2083 		if (*sp == '\0')
2084 			return nfserr_bad_xdr;
2085 		*dp++ = *sp++;
2086 	}
2087 	*dp = '\0';
2088 
2089 	*namep = name;
2090 
2091 	return nfs_ok;
2092 }
2093 
2094 /*
2095  * A GETXATTR op request comes without a length specifier. We just set the
2096  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2097  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2098  * check it against getxa_len, and allocate + return the value.
2099  */
2100 static __be32
2101 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2102 		      struct nfsd4_getxattr *getxattr)
2103 {
2104 	__be32 status;
2105 	u32 maxcount;
2106 
2107 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2108 	if (status)
2109 		return status;
2110 
2111 	maxcount = svc_max_payload(argp->rqstp);
2112 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2113 
2114 	getxattr->getxa_len = maxcount;
2115 
2116 	return status;
2117 }
2118 
2119 static __be32
2120 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2121 		      struct nfsd4_setxattr *setxattr)
2122 {
2123 	u32 flags, maxcount, size;
2124 	__be32 status;
2125 
2126 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2127 		return nfserr_bad_xdr;
2128 
2129 	if (flags > SETXATTR4_REPLACE)
2130 		return nfserr_inval;
2131 	setxattr->setxa_flags = flags;
2132 
2133 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2134 	if (status)
2135 		return status;
2136 
2137 	maxcount = svc_max_payload(argp->rqstp);
2138 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2139 
2140 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2141 		return nfserr_bad_xdr;
2142 	if (size > maxcount)
2143 		return nfserr_xattr2big;
2144 
2145 	setxattr->setxa_len = size;
2146 	if (size > 0) {
2147 		struct xdr_buf payload;
2148 
2149 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2150 			return nfserr_bad_xdr;
2151 		status = nfsd4_vbuf_from_vector(argp, &payload,
2152 						&setxattr->setxa_buf, size);
2153 	}
2154 
2155 	return nfs_ok;
2156 }
2157 
2158 static __be32
2159 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2160 			struct nfsd4_listxattrs *listxattrs)
2161 {
2162 	u32 maxcount;
2163 
2164 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2165 		return nfserr_bad_xdr;
2166 
2167 	/*
2168 	 * If the cookie  is too large to have even one user.x attribute
2169 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2170 	 */
2171 	if (listxattrs->lsxa_cookie >=
2172 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2173 		return nfserr_badcookie;
2174 
2175 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2176 		return nfserr_bad_xdr;
2177 	if (maxcount < 8)
2178 		/* Always need at least 2 words (length and one character) */
2179 		return nfserr_inval;
2180 
2181 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2182 	listxattrs->lsxa_maxcount = maxcount;
2183 
2184 	return nfs_ok;
2185 }
2186 
2187 static __be32
2188 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2189 			 struct nfsd4_removexattr *removexattr)
2190 {
2191 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2192 }
2193 
2194 static __be32
2195 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
2196 {
2197 	return nfs_ok;
2198 }
2199 
2200 static __be32
2201 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
2202 {
2203 	return nfserr_notsupp;
2204 }
2205 
2206 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
2207 
2208 static const nfsd4_dec nfsd4_dec_ops[] = {
2209 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
2210 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
2211 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
2212 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
2213 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2214 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
2215 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
2216 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
2217 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
2218 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
2219 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
2220 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
2221 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
2222 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
2223 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2224 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
2225 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
2226 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
2227 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
2228 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
2229 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
2230 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
2231 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
2232 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
2233 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
2234 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
2235 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
2236 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
2237 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
2238 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
2239 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
2240 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
2241 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
2242 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
2243 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2244 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
2245 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
2246 
2247 	/* new operations for NFSv4.1 */
2248 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
2249 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
2250 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
2251 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
2252 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
2253 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
2254 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2255 #ifdef CONFIG_NFSD_PNFS
2256 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
2257 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2258 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
2259 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
2260 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
2261 #else
2262 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
2263 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2264 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
2265 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
2266 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
2267 #endif
2268 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
2269 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
2270 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
2271 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
2272 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2273 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
2274 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
2275 
2276 	/* new operations for NFSv4.2 */
2277 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2278 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
2279 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_copy_notify,
2280 	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2281 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2282 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
2283 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
2284 	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
2285 	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
2286 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_read,
2287 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
2288 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
2289 	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
2290 	/* RFC 8276 extended atributes operations */
2291 	[OP_GETXATTR]		= (nfsd4_dec)nfsd4_decode_getxattr,
2292 	[OP_SETXATTR]		= (nfsd4_dec)nfsd4_decode_setxattr,
2293 	[OP_LISTXATTRS]		= (nfsd4_dec)nfsd4_decode_listxattrs,
2294 	[OP_REMOVEXATTR]	= (nfsd4_dec)nfsd4_decode_removexattr,
2295 };
2296 
2297 static inline bool
2298 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2299 {
2300 	if (op->opnum < FIRST_NFS4_OP)
2301 		return false;
2302 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2303 		return false;
2304 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2305 		return false;
2306 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2307 		return false;
2308 	return true;
2309 }
2310 
2311 static bool
2312 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2313 {
2314 	struct nfsd4_op *op;
2315 	bool cachethis = false;
2316 	int auth_slack= argp->rqstp->rq_auth_slack;
2317 	int max_reply = auth_slack + 8; /* opcnt, status */
2318 	int readcount = 0;
2319 	int readbytes = 0;
2320 	__be32 *p;
2321 	int i;
2322 
2323 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2324 		return false;
2325 	max_reply += XDR_UNIT;
2326 	argp->tag = NULL;
2327 	if (unlikely(argp->taglen)) {
2328 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2329 			return false;
2330 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2331 		if (!p)
2332 			return false;
2333 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2334 		if (!argp->tag)
2335 			return false;
2336 		max_reply += xdr_align_size(argp->taglen);
2337 	}
2338 
2339 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2340 		return false;
2341 	if (xdr_stream_decode_u32(argp->xdr, &argp->opcnt) < 0)
2342 		return false;
2343 
2344 	/*
2345 	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
2346 	 * here, so we return success at the xdr level so that
2347 	 * nfsd4_proc can handle this is an NFS-level error.
2348 	 */
2349 	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
2350 		return true;
2351 
2352 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2353 		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
2354 		if (!argp->ops) {
2355 			argp->ops = argp->iops;
2356 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
2357 			return false;
2358 		}
2359 	}
2360 
2361 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2362 		argp->opcnt = 0;
2363 
2364 	for (i = 0; i < argp->opcnt; i++) {
2365 		op = &argp->ops[i];
2366 		op->replay = NULL;
2367 
2368 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2369 			return false;
2370 		if (nfsd4_opnum_in_range(argp, op)) {
2371 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2372 			if (op->status != nfs_ok)
2373 				trace_nfsd_compound_decode_err(argp->rqstp,
2374 							       argp->opcnt, i,
2375 							       op->opnum,
2376 							       op->status);
2377 		} else {
2378 			op->opnum = OP_ILLEGAL;
2379 			op->status = nfserr_op_illegal;
2380 		}
2381 		op->opdesc = OPDESC(op);
2382 		/*
2383 		 * We'll try to cache the result in the DRC if any one
2384 		 * op in the compound wants to be cached:
2385 		 */
2386 		cachethis |= nfsd4_cache_this_op(op);
2387 
2388 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2389 			readcount++;
2390 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2391 		} else
2392 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2393 		/*
2394 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2395 		 * (Special case because it will just skip encoding this
2396 		 * if it runs out of xdr buffer space, and it is the only
2397 		 * operation that behaves this way.)
2398 		 */
2399 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2400 			max_reply += NFS4_OPAQUE_LIMIT;
2401 
2402 		if (op->status) {
2403 			argp->opcnt = i+1;
2404 			break;
2405 		}
2406 	}
2407 	/* Sessions make the DRC unnecessary: */
2408 	if (argp->minorversion)
2409 		cachethis = false;
2410 	svc_reserve(argp->rqstp, max_reply + readbytes);
2411 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2412 
2413 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2414 		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
2415 
2416 	return true;
2417 }
2418 
2419 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
2420 			     struct svc_export *exp)
2421 {
2422 	if (exp->ex_flags & NFSEXP_V4ROOT) {
2423 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
2424 		*p++ = 0;
2425 	} else
2426 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2427 	return p;
2428 }
2429 
2430 /*
2431  * ctime (in NFSv4, time_metadata) is not writeable, and the client
2432  * doesn't really care what resolution could theoretically be stored by
2433  * the filesystem.
2434  *
2435  * The client cares how close together changes can be while still
2436  * guaranteeing ctime changes.  For most filesystems (which have
2437  * timestamps with nanosecond fields) that is limited by the resolution
2438  * of the time returned from current_time() (which I'm assuming to be
2439  * 1/HZ).
2440  */
2441 static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
2442 {
2443 	struct timespec64 ts;
2444 	u32 ns;
2445 
2446 	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
2447 	ts = ns_to_timespec64(ns);
2448 
2449 	p = xdr_encode_hyper(p, ts.tv_sec);
2450 	*p++ = cpu_to_be32(ts.tv_nsec);
2451 
2452 	return p;
2453 }
2454 
2455 static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
2456 {
2457 	*p++ = cpu_to_be32(c->atomic);
2458 	p = xdr_encode_hyper(p, c->before_change);
2459 	p = xdr_encode_hyper(p, c->after_change);
2460 	return p;
2461 }
2462 
2463 /* Encode as an array of strings the string given with components
2464  * separated @sep, escaped with esc_enter and esc_exit.
2465  */
2466 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2467 					  char *components, char esc_enter,
2468 					  char esc_exit)
2469 {
2470 	__be32 *p;
2471 	__be32 pathlen;
2472 	int pathlen_offset;
2473 	int strlen, count=0;
2474 	char *str, *end, *next;
2475 
2476 	dprintk("nfsd4_encode_components(%s)\n", components);
2477 
2478 	pathlen_offset = xdr->buf->len;
2479 	p = xdr_reserve_space(xdr, 4);
2480 	if (!p)
2481 		return nfserr_resource;
2482 	p++; /* We will fill this in with @count later */
2483 
2484 	end = str = components;
2485 	while (*end) {
2486 		bool found_esc = false;
2487 
2488 		/* try to parse as esc_start, ..., esc_end, sep */
2489 		if (*str == esc_enter) {
2490 			for (; *end && (*end != esc_exit); end++)
2491 				/* find esc_exit or end of string */;
2492 			next = end + 1;
2493 			if (*end && (!*next || *next == sep)) {
2494 				str++;
2495 				found_esc = true;
2496 			}
2497 		}
2498 
2499 		if (!found_esc)
2500 			for (; *end && (*end != sep); end++)
2501 				/* find sep or end of string */;
2502 
2503 		strlen = end - str;
2504 		if (strlen) {
2505 			p = xdr_reserve_space(xdr, strlen + 4);
2506 			if (!p)
2507 				return nfserr_resource;
2508 			p = xdr_encode_opaque(p, str, strlen);
2509 			count++;
2510 		}
2511 		else
2512 			end++;
2513 		if (found_esc)
2514 			end = next;
2515 
2516 		str = end;
2517 	}
2518 	pathlen = htonl(count);
2519 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2520 	return 0;
2521 }
2522 
2523 /* Encode as an array of strings the string given with components
2524  * separated @sep.
2525  */
2526 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2527 				      char *components)
2528 {
2529 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2530 }
2531 
2532 /*
2533  * encode a location element of a fs_locations structure
2534  */
2535 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2536 					struct nfsd4_fs_location *location)
2537 {
2538 	__be32 status;
2539 
2540 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2541 						'[', ']');
2542 	if (status)
2543 		return status;
2544 	status = nfsd4_encode_components(xdr, '/', location->path);
2545 	if (status)
2546 		return status;
2547 	return 0;
2548 }
2549 
2550 /*
2551  * Encode a path in RFC3530 'pathname4' format
2552  */
2553 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2554 				const struct path *root,
2555 				const struct path *path)
2556 {
2557 	struct path cur = *path;
2558 	__be32 *p;
2559 	struct dentry **components = NULL;
2560 	unsigned int ncomponents = 0;
2561 	__be32 err = nfserr_jukebox;
2562 
2563 	dprintk("nfsd4_encode_components(");
2564 
2565 	path_get(&cur);
2566 	/* First walk the path up to the nfsd root, and store the
2567 	 * dentries/path components in an array.
2568 	 */
2569 	for (;;) {
2570 		if (path_equal(&cur, root))
2571 			break;
2572 		if (cur.dentry == cur.mnt->mnt_root) {
2573 			if (follow_up(&cur))
2574 				continue;
2575 			goto out_free;
2576 		}
2577 		if ((ncomponents & 15) == 0) {
2578 			struct dentry **new;
2579 			new = krealloc(components,
2580 					sizeof(*new) * (ncomponents + 16),
2581 					GFP_KERNEL);
2582 			if (!new)
2583 				goto out_free;
2584 			components = new;
2585 		}
2586 		components[ncomponents++] = cur.dentry;
2587 		cur.dentry = dget_parent(cur.dentry);
2588 	}
2589 	err = nfserr_resource;
2590 	p = xdr_reserve_space(xdr, 4);
2591 	if (!p)
2592 		goto out_free;
2593 	*p++ = cpu_to_be32(ncomponents);
2594 
2595 	while (ncomponents) {
2596 		struct dentry *dentry = components[ncomponents - 1];
2597 		unsigned int len;
2598 
2599 		spin_lock(&dentry->d_lock);
2600 		len = dentry->d_name.len;
2601 		p = xdr_reserve_space(xdr, len + 4);
2602 		if (!p) {
2603 			spin_unlock(&dentry->d_lock);
2604 			goto out_free;
2605 		}
2606 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2607 		dprintk("/%pd", dentry);
2608 		spin_unlock(&dentry->d_lock);
2609 		dput(dentry);
2610 		ncomponents--;
2611 	}
2612 
2613 	err = 0;
2614 out_free:
2615 	dprintk(")\n");
2616 	while (ncomponents)
2617 		dput(components[--ncomponents]);
2618 	kfree(components);
2619 	path_put(&cur);
2620 	return err;
2621 }
2622 
2623 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2624 			struct svc_rqst *rqstp, const struct path *path)
2625 {
2626 	struct svc_export *exp_ps;
2627 	__be32 res;
2628 
2629 	exp_ps = rqst_find_fsidzero_export(rqstp);
2630 	if (IS_ERR(exp_ps))
2631 		return nfserrno(PTR_ERR(exp_ps));
2632 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2633 	exp_put(exp_ps);
2634 	return res;
2635 }
2636 
2637 /*
2638  *  encode a fs_locations structure
2639  */
2640 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2641 			struct svc_rqst *rqstp, struct svc_export *exp)
2642 {
2643 	__be32 status;
2644 	int i;
2645 	__be32 *p;
2646 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2647 
2648 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2649 	if (status)
2650 		return status;
2651 	p = xdr_reserve_space(xdr, 4);
2652 	if (!p)
2653 		return nfserr_resource;
2654 	*p++ = cpu_to_be32(fslocs->locations_count);
2655 	for (i=0; i<fslocs->locations_count; i++) {
2656 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2657 		if (status)
2658 			return status;
2659 	}
2660 	return 0;
2661 }
2662 
2663 static u32 nfs4_file_type(umode_t mode)
2664 {
2665 	switch (mode & S_IFMT) {
2666 	case S_IFIFO:	return NF4FIFO;
2667 	case S_IFCHR:	return NF4CHR;
2668 	case S_IFDIR:	return NF4DIR;
2669 	case S_IFBLK:	return NF4BLK;
2670 	case S_IFLNK:	return NF4LNK;
2671 	case S_IFREG:	return NF4REG;
2672 	case S_IFSOCK:	return NF4SOCK;
2673 	default:	return NF4BAD;
2674 	}
2675 }
2676 
2677 static inline __be32
2678 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2679 		     struct nfs4_ace *ace)
2680 {
2681 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2682 		return nfs4_acl_write_who(xdr, ace->whotype);
2683 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2684 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2685 	else
2686 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2687 }
2688 
2689 static inline __be32
2690 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2691 {
2692 	__be32		*p;
2693 	unsigned long	i = hweight_long(layout_types);
2694 
2695 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2696 	if (!p)
2697 		return nfserr_resource;
2698 
2699 	*p++ = cpu_to_be32(i);
2700 
2701 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2702 		if (layout_types & (1 << i))
2703 			*p++ = cpu_to_be32(i);
2704 
2705 	return 0;
2706 }
2707 
2708 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2709 			      FATTR4_WORD0_RDATTR_ERROR)
2710 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2711 #define WORD2_ABSENT_FS_ATTRS 0
2712 
2713 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2714 static inline __be32
2715 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2716 			    void *context, int len)
2717 {
2718 	__be32 *p;
2719 
2720 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2721 	if (!p)
2722 		return nfserr_resource;
2723 
2724 	/*
2725 	 * For now we use a 0 here to indicate the null translation; in
2726 	 * the future we may place a call to translation code here.
2727 	 */
2728 	*p++ = cpu_to_be32(0); /* lfs */
2729 	*p++ = cpu_to_be32(0); /* pi */
2730 	p = xdr_encode_opaque(p, context, len);
2731 	return 0;
2732 }
2733 #else
2734 static inline __be32
2735 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2736 			    void *context, int len)
2737 { return 0; }
2738 #endif
2739 
2740 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2741 {
2742 	/* As per referral draft:  */
2743 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2744 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2745 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2746 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2747 			*rdattr_err = NFSERR_MOVED;
2748 		else
2749 			return nfserr_moved;
2750 	}
2751 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2752 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2753 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2754 	return 0;
2755 }
2756 
2757 
2758 static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
2759 {
2760 	struct path path = exp->ex_path;
2761 	int err;
2762 
2763 	path_get(&path);
2764 	while (follow_up(&path)) {
2765 		if (path.dentry != path.mnt->mnt_root)
2766 			break;
2767 	}
2768 	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2769 	path_put(&path);
2770 	return err;
2771 }
2772 
2773 static __be32
2774 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2775 {
2776 	__be32 *p;
2777 
2778 	if (bmval2) {
2779 		p = xdr_reserve_space(xdr, 16);
2780 		if (!p)
2781 			goto out_resource;
2782 		*p++ = cpu_to_be32(3);
2783 		*p++ = cpu_to_be32(bmval0);
2784 		*p++ = cpu_to_be32(bmval1);
2785 		*p++ = cpu_to_be32(bmval2);
2786 	} else if (bmval1) {
2787 		p = xdr_reserve_space(xdr, 12);
2788 		if (!p)
2789 			goto out_resource;
2790 		*p++ = cpu_to_be32(2);
2791 		*p++ = cpu_to_be32(bmval0);
2792 		*p++ = cpu_to_be32(bmval1);
2793 	} else {
2794 		p = xdr_reserve_space(xdr, 8);
2795 		if (!p)
2796 			goto out_resource;
2797 		*p++ = cpu_to_be32(1);
2798 		*p++ = cpu_to_be32(bmval0);
2799 	}
2800 
2801 	return 0;
2802 out_resource:
2803 	return nfserr_resource;
2804 }
2805 
2806 /*
2807  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2808  * ourselves.
2809  */
2810 static __be32
2811 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2812 		struct svc_export *exp,
2813 		struct dentry *dentry, u32 *bmval,
2814 		struct svc_rqst *rqstp, int ignore_crossmnt)
2815 {
2816 	u32 bmval0 = bmval[0];
2817 	u32 bmval1 = bmval[1];
2818 	u32 bmval2 = bmval[2];
2819 	struct kstat stat;
2820 	struct svc_fh *tempfh = NULL;
2821 	struct kstatfs statfs;
2822 	__be32 *p;
2823 	int starting_len = xdr->buf->len;
2824 	int attrlen_offset;
2825 	__be32 attrlen;
2826 	u32 dummy;
2827 	u64 dummy64;
2828 	u32 rdattr_err = 0;
2829 	__be32 status;
2830 	int err;
2831 	struct nfs4_acl *acl = NULL;
2832 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2833 	void *context = NULL;
2834 	int contextlen;
2835 #endif
2836 	bool contextsupport = false;
2837 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2838 	u32 minorversion = resp->cstate.minorversion;
2839 	struct path path = {
2840 		.mnt	= exp->ex_path.mnt,
2841 		.dentry	= dentry,
2842 	};
2843 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2844 
2845 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2846 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2847 
2848 	if (exp->ex_fslocs.migrated) {
2849 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2850 		if (status)
2851 			goto out;
2852 	}
2853 
2854 	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2855 	if (err)
2856 		goto out_nfserr;
2857 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
2858 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
2859 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2860 		       FATTR4_WORD1_SPACE_TOTAL))) {
2861 		err = vfs_statfs(&path, &statfs);
2862 		if (err)
2863 			goto out_nfserr;
2864 	}
2865 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2866 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
2867 		status = nfserr_jukebox;
2868 		if (!tempfh)
2869 			goto out;
2870 		fh_init(tempfh, NFS4_FHSIZE);
2871 		status = fh_compose(tempfh, exp, dentry, NULL);
2872 		if (status)
2873 			goto out;
2874 		fhp = tempfh;
2875 	}
2876 	if (bmval0 & FATTR4_WORD0_ACL) {
2877 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2878 		if (err == -EOPNOTSUPP)
2879 			bmval0 &= ~FATTR4_WORD0_ACL;
2880 		else if (err == -EINVAL) {
2881 			status = nfserr_attrnotsupp;
2882 			goto out;
2883 		} else if (err != 0)
2884 			goto out_nfserr;
2885 	}
2886 
2887 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2888 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
2889 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2890 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
2891 			err = security_inode_getsecctx(d_inode(dentry),
2892 						&context, &contextlen);
2893 		else
2894 			err = -EOPNOTSUPP;
2895 		contextsupport = (err == 0);
2896 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2897 			if (err == -EOPNOTSUPP)
2898 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
2899 			else if (err)
2900 				goto out_nfserr;
2901 		}
2902 	}
2903 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2904 
2905 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
2906 	if (status)
2907 		goto out;
2908 
2909 	attrlen_offset = xdr->buf->len;
2910 	p = xdr_reserve_space(xdr, 4);
2911 	if (!p)
2912 		goto out_resource;
2913 	p++;                /* to be backfilled later */
2914 
2915 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2916 		u32 supp[3];
2917 
2918 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2919 
2920 		if (!IS_POSIXACL(dentry->d_inode))
2921 			supp[0] &= ~FATTR4_WORD0_ACL;
2922 		if (!contextsupport)
2923 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2924 		if (!supp[2]) {
2925 			p = xdr_reserve_space(xdr, 12);
2926 			if (!p)
2927 				goto out_resource;
2928 			*p++ = cpu_to_be32(2);
2929 			*p++ = cpu_to_be32(supp[0]);
2930 			*p++ = cpu_to_be32(supp[1]);
2931 		} else {
2932 			p = xdr_reserve_space(xdr, 16);
2933 			if (!p)
2934 				goto out_resource;
2935 			*p++ = cpu_to_be32(3);
2936 			*p++ = cpu_to_be32(supp[0]);
2937 			*p++ = cpu_to_be32(supp[1]);
2938 			*p++ = cpu_to_be32(supp[2]);
2939 		}
2940 	}
2941 	if (bmval0 & FATTR4_WORD0_TYPE) {
2942 		p = xdr_reserve_space(xdr, 4);
2943 		if (!p)
2944 			goto out_resource;
2945 		dummy = nfs4_file_type(stat.mode);
2946 		if (dummy == NF4BAD) {
2947 			status = nfserr_serverfault;
2948 			goto out;
2949 		}
2950 		*p++ = cpu_to_be32(dummy);
2951 	}
2952 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2953 		p = xdr_reserve_space(xdr, 4);
2954 		if (!p)
2955 			goto out_resource;
2956 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2957 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
2958 		else
2959 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
2960 						NFS4_FH_VOL_RENAME);
2961 	}
2962 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2963 		p = xdr_reserve_space(xdr, 8);
2964 		if (!p)
2965 			goto out_resource;
2966 		p = encode_change(p, &stat, d_inode(dentry), exp);
2967 	}
2968 	if (bmval0 & FATTR4_WORD0_SIZE) {
2969 		p = xdr_reserve_space(xdr, 8);
2970 		if (!p)
2971 			goto out_resource;
2972 		p = xdr_encode_hyper(p, stat.size);
2973 	}
2974 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2975 		p = xdr_reserve_space(xdr, 4);
2976 		if (!p)
2977 			goto out_resource;
2978 		*p++ = cpu_to_be32(1);
2979 	}
2980 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
2981 		p = xdr_reserve_space(xdr, 4);
2982 		if (!p)
2983 			goto out_resource;
2984 		*p++ = cpu_to_be32(1);
2985 	}
2986 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
2987 		p = xdr_reserve_space(xdr, 4);
2988 		if (!p)
2989 			goto out_resource;
2990 		*p++ = cpu_to_be32(0);
2991 	}
2992 	if (bmval0 & FATTR4_WORD0_FSID) {
2993 		p = xdr_reserve_space(xdr, 16);
2994 		if (!p)
2995 			goto out_resource;
2996 		if (exp->ex_fslocs.migrated) {
2997 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
2998 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
2999 		} else switch(fsid_source(fhp)) {
3000 		case FSIDSOURCE_FSID:
3001 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
3002 			p = xdr_encode_hyper(p, (u64)0);
3003 			break;
3004 		case FSIDSOURCE_DEV:
3005 			*p++ = cpu_to_be32(0);
3006 			*p++ = cpu_to_be32(MAJOR(stat.dev));
3007 			*p++ = cpu_to_be32(0);
3008 			*p++ = cpu_to_be32(MINOR(stat.dev));
3009 			break;
3010 		case FSIDSOURCE_UUID:
3011 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
3012 								EX_UUID_LEN);
3013 			break;
3014 		}
3015 	}
3016 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
3017 		p = xdr_reserve_space(xdr, 4);
3018 		if (!p)
3019 			goto out_resource;
3020 		*p++ = cpu_to_be32(0);
3021 	}
3022 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
3023 		p = xdr_reserve_space(xdr, 4);
3024 		if (!p)
3025 			goto out_resource;
3026 		*p++ = cpu_to_be32(nn->nfsd4_lease);
3027 	}
3028 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
3029 		p = xdr_reserve_space(xdr, 4);
3030 		if (!p)
3031 			goto out_resource;
3032 		*p++ = cpu_to_be32(rdattr_err);
3033 	}
3034 	if (bmval0 & FATTR4_WORD0_ACL) {
3035 		struct nfs4_ace *ace;
3036 
3037 		if (acl == NULL) {
3038 			p = xdr_reserve_space(xdr, 4);
3039 			if (!p)
3040 				goto out_resource;
3041 
3042 			*p++ = cpu_to_be32(0);
3043 			goto out_acl;
3044 		}
3045 		p = xdr_reserve_space(xdr, 4);
3046 		if (!p)
3047 			goto out_resource;
3048 		*p++ = cpu_to_be32(acl->naces);
3049 
3050 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3051 			p = xdr_reserve_space(xdr, 4*3);
3052 			if (!p)
3053 				goto out_resource;
3054 			*p++ = cpu_to_be32(ace->type);
3055 			*p++ = cpu_to_be32(ace->flag);
3056 			*p++ = cpu_to_be32(ace->access_mask &
3057 							NFS4_ACE_MASK_ALL);
3058 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
3059 			if (status)
3060 				goto out;
3061 		}
3062 	}
3063 out_acl:
3064 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
3065 		p = xdr_reserve_space(xdr, 4);
3066 		if (!p)
3067 			goto out_resource;
3068 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
3069 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
3070 	}
3071 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
3072 		p = xdr_reserve_space(xdr, 4);
3073 		if (!p)
3074 			goto out_resource;
3075 		*p++ = cpu_to_be32(1);
3076 	}
3077 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
3078 		p = xdr_reserve_space(xdr, 4);
3079 		if (!p)
3080 			goto out_resource;
3081 		*p++ = cpu_to_be32(0);
3082 	}
3083 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
3084 		p = xdr_reserve_space(xdr, 4);
3085 		if (!p)
3086 			goto out_resource;
3087 		*p++ = cpu_to_be32(1);
3088 	}
3089 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
3090 		p = xdr_reserve_space(xdr, 4);
3091 		if (!p)
3092 			goto out_resource;
3093 		*p++ = cpu_to_be32(1);
3094 	}
3095 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
3096 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
3097 		if (!p)
3098 			goto out_resource;
3099 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw,
3100 					fhp->fh_handle.fh_size);
3101 	}
3102 	if (bmval0 & FATTR4_WORD0_FILEID) {
3103 		p = xdr_reserve_space(xdr, 8);
3104 		if (!p)
3105 			goto out_resource;
3106 		p = xdr_encode_hyper(p, stat.ino);
3107 	}
3108 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
3109 		p = xdr_reserve_space(xdr, 8);
3110 		if (!p)
3111 			goto out_resource;
3112 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3113 	}
3114 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
3115 		p = xdr_reserve_space(xdr, 8);
3116 		if (!p)
3117 			goto out_resource;
3118 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3119 	}
3120 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
3121 		p = xdr_reserve_space(xdr, 8);
3122 		if (!p)
3123 			goto out_resource;
3124 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
3125 	}
3126 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
3127 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
3128 		if (status)
3129 			goto out;
3130 	}
3131 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
3132 		p = xdr_reserve_space(xdr, 4);
3133 		if (!p)
3134 			goto out_resource;
3135 		*p++ = cpu_to_be32(1);
3136 	}
3137 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
3138 		p = xdr_reserve_space(xdr, 8);
3139 		if (!p)
3140 			goto out_resource;
3141 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
3142 	}
3143 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
3144 		p = xdr_reserve_space(xdr, 4);
3145 		if (!p)
3146 			goto out_resource;
3147 		*p++ = cpu_to_be32(255);
3148 	}
3149 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
3150 		p = xdr_reserve_space(xdr, 4);
3151 		if (!p)
3152 			goto out_resource;
3153 		*p++ = cpu_to_be32(statfs.f_namelen);
3154 	}
3155 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
3156 		p = xdr_reserve_space(xdr, 8);
3157 		if (!p)
3158 			goto out_resource;
3159 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3160 	}
3161 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
3162 		p = xdr_reserve_space(xdr, 8);
3163 		if (!p)
3164 			goto out_resource;
3165 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3166 	}
3167 	if (bmval1 & FATTR4_WORD1_MODE) {
3168 		p = xdr_reserve_space(xdr, 4);
3169 		if (!p)
3170 			goto out_resource;
3171 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
3172 	}
3173 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
3174 		p = xdr_reserve_space(xdr, 4);
3175 		if (!p)
3176 			goto out_resource;
3177 		*p++ = cpu_to_be32(1);
3178 	}
3179 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
3180 		p = xdr_reserve_space(xdr, 4);
3181 		if (!p)
3182 			goto out_resource;
3183 		*p++ = cpu_to_be32(stat.nlink);
3184 	}
3185 	if (bmval1 & FATTR4_WORD1_OWNER) {
3186 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
3187 		if (status)
3188 			goto out;
3189 	}
3190 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
3191 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
3192 		if (status)
3193 			goto out;
3194 	}
3195 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
3196 		p = xdr_reserve_space(xdr, 8);
3197 		if (!p)
3198 			goto out_resource;
3199 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
3200 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
3201 	}
3202 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
3203 		p = xdr_reserve_space(xdr, 8);
3204 		if (!p)
3205 			goto out_resource;
3206 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
3207 		p = xdr_encode_hyper(p, dummy64);
3208 	}
3209 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
3210 		p = xdr_reserve_space(xdr, 8);
3211 		if (!p)
3212 			goto out_resource;
3213 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
3214 		p = xdr_encode_hyper(p, dummy64);
3215 	}
3216 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
3217 		p = xdr_reserve_space(xdr, 8);
3218 		if (!p)
3219 			goto out_resource;
3220 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
3221 		p = xdr_encode_hyper(p, dummy64);
3222 	}
3223 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
3224 		p = xdr_reserve_space(xdr, 8);
3225 		if (!p)
3226 			goto out_resource;
3227 		dummy64 = (u64)stat.blocks << 9;
3228 		p = xdr_encode_hyper(p, dummy64);
3229 	}
3230 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
3231 		p = xdr_reserve_space(xdr, 12);
3232 		if (!p)
3233 			goto out_resource;
3234 		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
3235 		*p++ = cpu_to_be32(stat.atime.tv_nsec);
3236 	}
3237 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
3238 		p = xdr_reserve_space(xdr, 12);
3239 		if (!p)
3240 			goto out_resource;
3241 		p = encode_time_delta(p, d_inode(dentry));
3242 	}
3243 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
3244 		p = xdr_reserve_space(xdr, 12);
3245 		if (!p)
3246 			goto out_resource;
3247 		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
3248 		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
3249 	}
3250 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
3251 		p = xdr_reserve_space(xdr, 12);
3252 		if (!p)
3253 			goto out_resource;
3254 		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
3255 		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
3256 	}
3257 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
3258 		struct kstat parent_stat;
3259 		u64 ino = stat.ino;
3260 
3261 		p = xdr_reserve_space(xdr, 8);
3262 		if (!p)
3263                 	goto out_resource;
3264 		/*
3265 		 * Get parent's attributes if not ignoring crossmount
3266 		 * and this is the root of a cross-mounted filesystem.
3267 		 */
3268 		if (ignore_crossmnt == 0 &&
3269 		    dentry == exp->ex_path.mnt->mnt_root) {
3270 			err = get_parent_attributes(exp, &parent_stat);
3271 			if (err)
3272 				goto out_nfserr;
3273 			ino = parent_stat.ino;
3274 		}
3275 		p = xdr_encode_hyper(p, ino);
3276 	}
3277 #ifdef CONFIG_NFSD_PNFS
3278 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
3279 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3280 		if (status)
3281 			goto out;
3282 	}
3283 
3284 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
3285 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3286 		if (status)
3287 			goto out;
3288 	}
3289 
3290 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
3291 		p = xdr_reserve_space(xdr, 4);
3292 		if (!p)
3293 			goto out_resource;
3294 		*p++ = cpu_to_be32(stat.blksize);
3295 	}
3296 #endif /* CONFIG_NFSD_PNFS */
3297 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
3298 		u32 supp[3];
3299 
3300 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
3301 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3302 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3303 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3304 
3305 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
3306 		if (status)
3307 			goto out;
3308 	}
3309 
3310 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3311 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
3312 		status = nfsd4_encode_security_label(xdr, rqstp, context,
3313 								contextlen);
3314 		if (status)
3315 			goto out;
3316 	}
3317 #endif
3318 
3319 	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
3320 		p = xdr_reserve_space(xdr, 4);
3321 		if (!p)
3322 			goto out_resource;
3323 		err = xattr_supported_namespace(d_inode(dentry),
3324 						XATTR_USER_PREFIX);
3325 		*p++ = cpu_to_be32(err == 0);
3326 	}
3327 
3328 	attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
3329 	write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
3330 	status = nfs_ok;
3331 
3332 out:
3333 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3334 	if (context)
3335 		security_release_secctx(context, contextlen);
3336 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3337 	kfree(acl);
3338 	if (tempfh) {
3339 		fh_put(tempfh);
3340 		kfree(tempfh);
3341 	}
3342 	if (status)
3343 		xdr_truncate_encode(xdr, starting_len);
3344 	return status;
3345 out_nfserr:
3346 	status = nfserrno(err);
3347 	goto out;
3348 out_resource:
3349 	status = nfserr_resource;
3350 	goto out;
3351 }
3352 
3353 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3354 				struct xdr_buf *buf, __be32 *p, int bytes)
3355 {
3356 	xdr->scratch.iov_len = 0;
3357 	memset(buf, 0, sizeof(struct xdr_buf));
3358 	buf->head[0].iov_base = p;
3359 	buf->head[0].iov_len = 0;
3360 	buf->len = 0;
3361 	xdr->buf = buf;
3362 	xdr->iov = buf->head;
3363 	xdr->p = p;
3364 	xdr->end = (void *)p + bytes;
3365 	buf->buflen = bytes;
3366 }
3367 
3368 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3369 			struct svc_fh *fhp, struct svc_export *exp,
3370 			struct dentry *dentry, u32 *bmval,
3371 			struct svc_rqst *rqstp, int ignore_crossmnt)
3372 {
3373 	struct xdr_buf dummy;
3374 	struct xdr_stream xdr;
3375 	__be32 ret;
3376 
3377 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3378 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
3379 							ignore_crossmnt);
3380 	*p = xdr.p;
3381 	return ret;
3382 }
3383 
3384 static inline int attributes_need_mount(u32 *bmval)
3385 {
3386 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3387 		return 1;
3388 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3389 		return 1;
3390 	return 0;
3391 }
3392 
3393 static __be32
3394 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
3395 			const char *name, int namlen)
3396 {
3397 	struct svc_export *exp = cd->rd_fhp->fh_export;
3398 	struct dentry *dentry;
3399 	__be32 nfserr;
3400 	int ignore_crossmnt = 0;
3401 
3402 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3403 	if (IS_ERR(dentry))
3404 		return nfserrno(PTR_ERR(dentry));
3405 
3406 	exp_get(exp);
3407 	/*
3408 	 * In the case of a mountpoint, the client may be asking for
3409 	 * attributes that are only properties of the underlying filesystem
3410 	 * as opposed to the cross-mounted file system. In such a case,
3411 	 * we will not follow the cross mount and will fill the attribtutes
3412 	 * directly from the mountpoint dentry.
3413 	 */
3414 	if (nfsd_mountpoint(dentry, exp)) {
3415 		int err;
3416 
3417 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3418 				&& !attributes_need_mount(cd->rd_bmval)) {
3419 			ignore_crossmnt = 1;
3420 			goto out_encode;
3421 		}
3422 		/*
3423 		 * Why the heck aren't we just using nfsd_lookup??
3424 		 * Different "."/".." handling?  Something else?
3425 		 * At least, add a comment here to explain....
3426 		 */
3427 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3428 		if (err) {
3429 			nfserr = nfserrno(err);
3430 			goto out_put;
3431 		}
3432 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3433 		if (nfserr)
3434 			goto out_put;
3435 
3436 	}
3437 out_encode:
3438 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
3439 					cd->rd_rqstp, ignore_crossmnt);
3440 out_put:
3441 	dput(dentry);
3442 	exp_put(exp);
3443 	return nfserr;
3444 }
3445 
3446 static __be32 *
3447 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3448 {
3449 	__be32 *p;
3450 
3451 	p = xdr_reserve_space(xdr, 20);
3452 	if (!p)
3453 		return NULL;
3454 	*p++ = htonl(2);
3455 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3456 	*p++ = htonl(0);			 /* bmval1 */
3457 
3458 	*p++ = htonl(4);     /* attribute length */
3459 	*p++ = nfserr;       /* no htonl */
3460 	return p;
3461 }
3462 
3463 static int
3464 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3465 		    loff_t offset, u64 ino, unsigned int d_type)
3466 {
3467 	struct readdir_cd *ccd = ccdv;
3468 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3469 	struct xdr_stream *xdr = cd->xdr;
3470 	int start_offset = xdr->buf->len;
3471 	int cookie_offset;
3472 	u32 name_and_cookie;
3473 	int entry_bytes;
3474 	__be32 nfserr = nfserr_toosmall;
3475 	__be64 wire_offset;
3476 	__be32 *p;
3477 
3478 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3479 	if (name && isdotent(name, namlen)) {
3480 		cd->common.err = nfs_ok;
3481 		return 0;
3482 	}
3483 
3484 	if (cd->cookie_offset) {
3485 		wire_offset = cpu_to_be64(offset);
3486 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3487 							&wire_offset, 8);
3488 	}
3489 
3490 	p = xdr_reserve_space(xdr, 4);
3491 	if (!p)
3492 		goto fail;
3493 	*p++ = xdr_one;                             /* mark entry present */
3494 	cookie_offset = xdr->buf->len;
3495 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3496 	if (!p)
3497 		goto fail;
3498 	p = xdr_encode_hyper(p, OFFSET_MAX);        /* offset of next entry */
3499 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3500 
3501 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3502 	switch (nfserr) {
3503 	case nfs_ok:
3504 		break;
3505 	case nfserr_resource:
3506 		nfserr = nfserr_toosmall;
3507 		goto fail;
3508 	case nfserr_noent:
3509 		xdr_truncate_encode(xdr, start_offset);
3510 		goto skip_entry;
3511 	default:
3512 		/*
3513 		 * If the client requested the RDATTR_ERROR attribute,
3514 		 * we stuff the error code into this attribute
3515 		 * and continue.  If this attribute was not requested,
3516 		 * then in accordance with the spec, we fail the
3517 		 * entire READDIR operation(!)
3518 		 */
3519 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3520 			goto fail;
3521 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3522 		if (p == NULL) {
3523 			nfserr = nfserr_toosmall;
3524 			goto fail;
3525 		}
3526 	}
3527 	nfserr = nfserr_toosmall;
3528 	entry_bytes = xdr->buf->len - start_offset;
3529 	if (entry_bytes > cd->rd_maxcount)
3530 		goto fail;
3531 	cd->rd_maxcount -= entry_bytes;
3532 	/*
3533 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3534 	 * notes that it could be zero. If it is zero, then the server
3535 	 * should enforce only the rd_maxcount value.
3536 	 */
3537 	if (cd->rd_dircount) {
3538 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3539 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3540 			goto fail;
3541 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3542 		if (!cd->rd_dircount)
3543 			cd->rd_maxcount = 0;
3544 	}
3545 
3546 	cd->cookie_offset = cookie_offset;
3547 skip_entry:
3548 	cd->common.err = nfs_ok;
3549 	return 0;
3550 fail:
3551 	xdr_truncate_encode(xdr, start_offset);
3552 	cd->common.err = nfserr;
3553 	return -EINVAL;
3554 }
3555 
3556 static __be32
3557 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3558 {
3559 	__be32 *p;
3560 
3561 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3562 	if (!p)
3563 		return nfserr_resource;
3564 	*p++ = cpu_to_be32(sid->si_generation);
3565 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3566 					sizeof(stateid_opaque_t));
3567 	return 0;
3568 }
3569 
3570 static __be32
3571 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
3572 {
3573 	struct xdr_stream *xdr = resp->xdr;
3574 	__be32 *p;
3575 
3576 	p = xdr_reserve_space(xdr, 8);
3577 	if (!p)
3578 		return nfserr_resource;
3579 	*p++ = cpu_to_be32(access->ac_supported);
3580 	*p++ = cpu_to_be32(access->ac_resp_access);
3581 	return 0;
3582 }
3583 
3584 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
3585 {
3586 	struct xdr_stream *xdr = resp->xdr;
3587 	__be32 *p;
3588 
3589 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3590 	if (!p)
3591 		return nfserr_resource;
3592 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3593 					NFS4_MAX_SESSIONID_LEN);
3594 	*p++ = cpu_to_be32(bcts->dir);
3595 	/* Upshifting from TCP to RDMA is not supported */
3596 	*p++ = cpu_to_be32(0);
3597 	return 0;
3598 }
3599 
3600 static __be32
3601 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
3602 {
3603 	struct xdr_stream *xdr = resp->xdr;
3604 
3605 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3606 }
3607 
3608 
3609 static __be32
3610 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
3611 {
3612 	struct xdr_stream *xdr = resp->xdr;
3613 	__be32 *p;
3614 
3615 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3616 	if (!p)
3617 		return nfserr_resource;
3618 	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
3619 						NFS4_VERIFIER_SIZE);
3620 	return 0;
3621 }
3622 
3623 static __be32
3624 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
3625 {
3626 	struct xdr_stream *xdr = resp->xdr;
3627 	__be32 *p;
3628 
3629 	p = xdr_reserve_space(xdr, 20);
3630 	if (!p)
3631 		return nfserr_resource;
3632 	encode_cinfo(p, &create->cr_cinfo);
3633 	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3634 			create->cr_bmval[1], create->cr_bmval[2]);
3635 }
3636 
3637 static __be32
3638 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
3639 {
3640 	struct svc_fh *fhp = getattr->ga_fhp;
3641 	struct xdr_stream *xdr = resp->xdr;
3642 
3643 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3644 				    getattr->ga_bmval, resp->rqstp, 0);
3645 }
3646 
3647 static __be32
3648 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
3649 {
3650 	struct xdr_stream *xdr = resp->xdr;
3651 	struct svc_fh *fhp = *fhpp;
3652 	unsigned int len;
3653 	__be32 *p;
3654 
3655 	len = fhp->fh_handle.fh_size;
3656 	p = xdr_reserve_space(xdr, len + 4);
3657 	if (!p)
3658 		return nfserr_resource;
3659 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw, len);
3660 	return 0;
3661 }
3662 
3663 /*
3664 * Including all fields other than the name, a LOCK4denied structure requires
3665 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3666 */
3667 static __be32
3668 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3669 {
3670 	struct xdr_netobj *conf = &ld->ld_owner;
3671 	__be32 *p;
3672 
3673 again:
3674 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3675 	if (!p) {
3676 		/*
3677 		 * Don't fail to return the result just because we can't
3678 		 * return the conflicting open:
3679 		 */
3680 		if (conf->len) {
3681 			kfree(conf->data);
3682 			conf->len = 0;
3683 			conf->data = NULL;
3684 			goto again;
3685 		}
3686 		return nfserr_resource;
3687 	}
3688 	p = xdr_encode_hyper(p, ld->ld_start);
3689 	p = xdr_encode_hyper(p, ld->ld_length);
3690 	*p++ = cpu_to_be32(ld->ld_type);
3691 	if (conf->len) {
3692 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3693 		p = xdr_encode_opaque(p, conf->data, conf->len);
3694 		kfree(conf->data);
3695 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3696 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3697 		*p++ = cpu_to_be32(0); /* length of owner name */
3698 	}
3699 	return nfserr_denied;
3700 }
3701 
3702 static __be32
3703 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
3704 {
3705 	struct xdr_stream *xdr = resp->xdr;
3706 
3707 	if (!nfserr)
3708 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3709 	else if (nfserr == nfserr_denied)
3710 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3711 
3712 	return nfserr;
3713 }
3714 
3715 static __be32
3716 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
3717 {
3718 	struct xdr_stream *xdr = resp->xdr;
3719 
3720 	if (nfserr == nfserr_denied)
3721 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3722 	return nfserr;
3723 }
3724 
3725 static __be32
3726 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
3727 {
3728 	struct xdr_stream *xdr = resp->xdr;
3729 
3730 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3731 }
3732 
3733 
3734 static __be32
3735 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
3736 {
3737 	struct xdr_stream *xdr = resp->xdr;
3738 	__be32 *p;
3739 
3740 	p = xdr_reserve_space(xdr, 20);
3741 	if (!p)
3742 		return nfserr_resource;
3743 	p = encode_cinfo(p, &link->li_cinfo);
3744 	return 0;
3745 }
3746 
3747 
3748 static __be32
3749 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
3750 {
3751 	struct xdr_stream *xdr = resp->xdr;
3752 	__be32 *p;
3753 
3754 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3755 	if (nfserr)
3756 		return nfserr;
3757 	p = xdr_reserve_space(xdr, 24);
3758 	if (!p)
3759 		return nfserr_resource;
3760 	p = encode_cinfo(p, &open->op_cinfo);
3761 	*p++ = cpu_to_be32(open->op_rflags);
3762 
3763 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3764 					open->op_bmval[2]);
3765 	if (nfserr)
3766 		return nfserr;
3767 
3768 	p = xdr_reserve_space(xdr, 4);
3769 	if (!p)
3770 		return nfserr_resource;
3771 
3772 	*p++ = cpu_to_be32(open->op_delegate_type);
3773 	switch (open->op_delegate_type) {
3774 	case NFS4_OPEN_DELEGATE_NONE:
3775 		break;
3776 	case NFS4_OPEN_DELEGATE_READ:
3777 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3778 		if (nfserr)
3779 			return nfserr;
3780 		p = xdr_reserve_space(xdr, 20);
3781 		if (!p)
3782 			return nfserr_resource;
3783 		*p++ = cpu_to_be32(open->op_recall);
3784 
3785 		/*
3786 		 * TODO: ACE's in delegations
3787 		 */
3788 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3789 		*p++ = cpu_to_be32(0);
3790 		*p++ = cpu_to_be32(0);
3791 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3792 		break;
3793 	case NFS4_OPEN_DELEGATE_WRITE:
3794 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3795 		if (nfserr)
3796 			return nfserr;
3797 		p = xdr_reserve_space(xdr, 32);
3798 		if (!p)
3799 			return nfserr_resource;
3800 		*p++ = cpu_to_be32(0);
3801 
3802 		/*
3803 		 * TODO: space_limit's in delegations
3804 		 */
3805 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3806 		*p++ = cpu_to_be32(~(u32)0);
3807 		*p++ = cpu_to_be32(~(u32)0);
3808 
3809 		/*
3810 		 * TODO: ACE's in delegations
3811 		 */
3812 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3813 		*p++ = cpu_to_be32(0);
3814 		*p++ = cpu_to_be32(0);
3815 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3816 		break;
3817 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
3818 		switch (open->op_why_no_deleg) {
3819 		case WND4_CONTENTION:
3820 		case WND4_RESOURCE:
3821 			p = xdr_reserve_space(xdr, 8);
3822 			if (!p)
3823 				return nfserr_resource;
3824 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3825 			/* deleg signaling not supported yet: */
3826 			*p++ = cpu_to_be32(0);
3827 			break;
3828 		default:
3829 			p = xdr_reserve_space(xdr, 4);
3830 			if (!p)
3831 				return nfserr_resource;
3832 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3833 		}
3834 		break;
3835 	default:
3836 		BUG();
3837 	}
3838 	/* XXX save filehandle here */
3839 	return 0;
3840 }
3841 
3842 static __be32
3843 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
3844 {
3845 	struct xdr_stream *xdr = resp->xdr;
3846 
3847 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
3848 }
3849 
3850 static __be32
3851 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
3852 {
3853 	struct xdr_stream *xdr = resp->xdr;
3854 
3855 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
3856 }
3857 
3858 static __be32 nfsd4_encode_splice_read(
3859 				struct nfsd4_compoundres *resp,
3860 				struct nfsd4_read *read,
3861 				struct file *file, unsigned long maxcount)
3862 {
3863 	struct xdr_stream *xdr = resp->xdr;
3864 	struct xdr_buf *buf = xdr->buf;
3865 	int status, space_left;
3866 	u32 eof;
3867 	__be32 nfserr;
3868 	__be32 *p = xdr->p - 2;
3869 
3870 	/* Make sure there will be room for padding if needed */
3871 	if (xdr->end - xdr->p < 1)
3872 		return nfserr_resource;
3873 
3874 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
3875 				  file, read->rd_offset, &maxcount, &eof);
3876 	read->rd_length = maxcount;
3877 	if (nfserr)
3878 		goto out_err;
3879 	status = svc_encode_result_payload(read->rd_rqstp,
3880 					   buf->head[0].iov_len, maxcount);
3881 	if (status) {
3882 		nfserr = nfserrno(status);
3883 		goto out_err;
3884 	}
3885 
3886 	*(p++) = htonl(eof);
3887 	*(p++) = htonl(maxcount);
3888 
3889 	buf->page_len = maxcount;
3890 	buf->len += maxcount;
3891 	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
3892 							/ PAGE_SIZE;
3893 
3894 	/* Use rest of head for padding and remaining ops: */
3895 	buf->tail[0].iov_base = xdr->p;
3896 	buf->tail[0].iov_len = 0;
3897 	xdr->iov = buf->tail;
3898 	if (maxcount&3) {
3899 		int pad = 4 - (maxcount&3);
3900 
3901 		*(xdr->p++) = 0;
3902 
3903 		buf->tail[0].iov_base += maxcount&3;
3904 		buf->tail[0].iov_len = pad;
3905 		buf->len += pad;
3906 	}
3907 
3908 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
3909 				buf->buflen - buf->len);
3910 	buf->buflen = buf->len + space_left;
3911 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
3912 
3913 	return 0;
3914 
3915 out_err:
3916 	/*
3917 	 * nfsd_splice_actor may have already messed with the
3918 	 * page length; reset it so as not to confuse
3919 	 * xdr_truncate_encode in our caller.
3920 	 */
3921 	buf->page_len = 0;
3922 	return nfserr;
3923 }
3924 
3925 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
3926 				 struct nfsd4_read *read,
3927 				 struct file *file, unsigned long maxcount)
3928 {
3929 	struct xdr_stream *xdr = resp->xdr;
3930 	u32 eof;
3931 	int starting_len = xdr->buf->len - 8;
3932 	__be32 nfserr;
3933 	__be32 tmp;
3934 	int pad;
3935 
3936 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
3937 	if (read->rd_vlen < 0)
3938 		return nfserr_resource;
3939 
3940 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
3941 			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
3942 			    &eof);
3943 	read->rd_length = maxcount;
3944 	if (nfserr)
3945 		return nfserr;
3946 	if (svc_encode_result_payload(resp->rqstp, starting_len + 8, maxcount))
3947 		return nfserr_io;
3948 	xdr_truncate_encode(xdr, starting_len + 8 + xdr_align_size(maxcount));
3949 
3950 	tmp = htonl(eof);
3951 	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
3952 	tmp = htonl(maxcount);
3953 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
3954 
3955 	tmp = xdr_zero;
3956 	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
3957 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
3958 								&tmp, pad);
3959 	return 0;
3960 
3961 }
3962 
3963 static __be32
3964 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
3965 		  struct nfsd4_read *read)
3966 {
3967 	unsigned long maxcount;
3968 	struct xdr_stream *xdr = resp->xdr;
3969 	struct file *file;
3970 	int starting_len = xdr->buf->len;
3971 	__be32 *p;
3972 
3973 	if (nfserr)
3974 		return nfserr;
3975 	file = read->rd_nf->nf_file;
3976 
3977 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
3978 	if (!p) {
3979 		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
3980 		return nfserr_resource;
3981 	}
3982 	if (resp->xdr->buf->page_len &&
3983 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
3984 		WARN_ON_ONCE(1);
3985 		return nfserr_resource;
3986 	}
3987 	xdr_commit_encode(xdr);
3988 
3989 	maxcount = min_t(unsigned long, read->rd_length,
3990 			 (xdr->buf->buflen - xdr->buf->len));
3991 
3992 	if (file->f_op->splice_read &&
3993 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
3994 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
3995 	else
3996 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
3997 
3998 	if (nfserr)
3999 		xdr_truncate_encode(xdr, starting_len);
4000 
4001 	return nfserr;
4002 }
4003 
4004 static __be32
4005 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
4006 {
4007 	int maxcount;
4008 	__be32 wire_count;
4009 	int zero = 0;
4010 	struct xdr_stream *xdr = resp->xdr;
4011 	int length_offset = xdr->buf->len;
4012 	int status;
4013 	__be32 *p;
4014 
4015 	p = xdr_reserve_space(xdr, 4);
4016 	if (!p)
4017 		return nfserr_resource;
4018 	maxcount = PAGE_SIZE;
4019 
4020 	p = xdr_reserve_space(xdr, maxcount);
4021 	if (!p)
4022 		return nfserr_resource;
4023 	/*
4024 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4025 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4026 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4027 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4028 	 */
4029 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4030 						(char *)p, &maxcount);
4031 	if (nfserr == nfserr_isdir)
4032 		nfserr = nfserr_inval;
4033 	if (nfserr)
4034 		goto out_err;
4035 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4036 					   maxcount);
4037 	if (status) {
4038 		nfserr = nfserrno(status);
4039 		goto out_err;
4040 	}
4041 
4042 	wire_count = htonl(maxcount);
4043 	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
4044 	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
4045 	if (maxcount & 3)
4046 		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
4047 						&zero, 4 - (maxcount&3));
4048 	return 0;
4049 
4050 out_err:
4051 	xdr_truncate_encode(xdr, length_offset);
4052 	return nfserr;
4053 }
4054 
4055 static __be32
4056 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
4057 {
4058 	int maxcount;
4059 	int bytes_left;
4060 	loff_t offset;
4061 	__be64 wire_offset;
4062 	struct xdr_stream *xdr = resp->xdr;
4063 	int starting_len = xdr->buf->len;
4064 	__be32 *p;
4065 
4066 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
4067 	if (!p)
4068 		return nfserr_resource;
4069 
4070 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
4071 	*p++ = cpu_to_be32(0);
4072 	*p++ = cpu_to_be32(0);
4073 	xdr->buf->head[0].iov_len = (char *)xdr->p -
4074 				    (char *)xdr->buf->head[0].iov_base;
4075 
4076 	/*
4077 	 * Number of bytes left for directory entries allowing for the
4078 	 * final 8 bytes of the readdir and a following failed op:
4079 	 */
4080 	bytes_left = xdr->buf->buflen - xdr->buf->len
4081 			- COMPOUND_ERR_SLACK_SPACE - 8;
4082 	if (bytes_left < 0) {
4083 		nfserr = nfserr_resource;
4084 		goto err_no_verf;
4085 	}
4086 	maxcount = svc_max_payload(resp->rqstp);
4087 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
4088 	/*
4089 	 * Note the rfc defines rd_maxcount as the size of the
4090 	 * READDIR4resok structure, which includes the verifier above
4091 	 * and the 8 bytes encoded at the end of this function:
4092 	 */
4093 	if (maxcount < 16) {
4094 		nfserr = nfserr_toosmall;
4095 		goto err_no_verf;
4096 	}
4097 	maxcount = min_t(int, maxcount-16, bytes_left);
4098 
4099 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
4100 	if (!readdir->rd_dircount)
4101 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
4102 
4103 	readdir->xdr = xdr;
4104 	readdir->rd_maxcount = maxcount;
4105 	readdir->common.err = 0;
4106 	readdir->cookie_offset = 0;
4107 
4108 	offset = readdir->rd_cookie;
4109 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
4110 			      &offset,
4111 			      &readdir->common, nfsd4_encode_dirent);
4112 	if (nfserr == nfs_ok &&
4113 	    readdir->common.err == nfserr_toosmall &&
4114 	    xdr->buf->len == starting_len + 8) {
4115 		/* nothing encoded; which limit did we hit?: */
4116 		if (maxcount - 16 < bytes_left)
4117 			/* It was the fault of rd_maxcount: */
4118 			nfserr = nfserr_toosmall;
4119 		else
4120 			/* We ran out of buffer space: */
4121 			nfserr = nfserr_resource;
4122 	}
4123 	if (nfserr)
4124 		goto err_no_verf;
4125 
4126 	if (readdir->cookie_offset) {
4127 		wire_offset = cpu_to_be64(offset);
4128 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
4129 							&wire_offset, 8);
4130 	}
4131 
4132 	p = xdr_reserve_space(xdr, 8);
4133 	if (!p) {
4134 		WARN_ON_ONCE(1);
4135 		goto err_no_verf;
4136 	}
4137 	*p++ = 0;	/* no more entries */
4138 	*p++ = htonl(readdir->common.err == nfserr_eof);
4139 
4140 	return 0;
4141 err_no_verf:
4142 	xdr_truncate_encode(xdr, starting_len);
4143 	return nfserr;
4144 }
4145 
4146 static __be32
4147 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
4148 {
4149 	struct xdr_stream *xdr = resp->xdr;
4150 	__be32 *p;
4151 
4152 	p = xdr_reserve_space(xdr, 20);
4153 	if (!p)
4154 		return nfserr_resource;
4155 	p = encode_cinfo(p, &remove->rm_cinfo);
4156 	return 0;
4157 }
4158 
4159 static __be32
4160 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
4161 {
4162 	struct xdr_stream *xdr = resp->xdr;
4163 	__be32 *p;
4164 
4165 	p = xdr_reserve_space(xdr, 40);
4166 	if (!p)
4167 		return nfserr_resource;
4168 	p = encode_cinfo(p, &rename->rn_sinfo);
4169 	p = encode_cinfo(p, &rename->rn_tinfo);
4170 	return 0;
4171 }
4172 
4173 static __be32
4174 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4175 {
4176 	u32 i, nflavs, supported;
4177 	struct exp_flavor_info *flavs;
4178 	struct exp_flavor_info def_flavs[2];
4179 	__be32 *p, *flavorsp;
4180 	static bool report = true;
4181 
4182 	if (exp->ex_nflavors) {
4183 		flavs = exp->ex_flavors;
4184 		nflavs = exp->ex_nflavors;
4185 	} else { /* Handling of some defaults in absence of real secinfo: */
4186 		flavs = def_flavs;
4187 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4188 			nflavs = 2;
4189 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4190 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4191 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4192 			nflavs = 1;
4193 			flavs[0].pseudoflavor
4194 					= svcauth_gss_flavor(exp->ex_client);
4195 		} else {
4196 			nflavs = 1;
4197 			flavs[0].pseudoflavor
4198 					= exp->ex_client->flavour->flavour;
4199 		}
4200 	}
4201 
4202 	supported = 0;
4203 	p = xdr_reserve_space(xdr, 4);
4204 	if (!p)
4205 		return nfserr_resource;
4206 	flavorsp = p++;		/* to be backfilled later */
4207 
4208 	for (i = 0; i < nflavs; i++) {
4209 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4210 		struct rpcsec_gss_info info;
4211 
4212 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4213 			supported++;
4214 			p = xdr_reserve_space(xdr, 4 + 4 +
4215 					      XDR_LEN(info.oid.len) + 4 + 4);
4216 			if (!p)
4217 				return nfserr_resource;
4218 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
4219 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
4220 			*p++ = cpu_to_be32(info.qop);
4221 			*p++ = cpu_to_be32(info.service);
4222 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4223 			supported++;
4224 			p = xdr_reserve_space(xdr, 4);
4225 			if (!p)
4226 				return nfserr_resource;
4227 			*p++ = cpu_to_be32(pf);
4228 		} else {
4229 			if (report)
4230 				pr_warn("NFS: SECINFO: security flavor %u "
4231 					"is not supported\n", pf);
4232 		}
4233 	}
4234 
4235 	if (nflavs != supported)
4236 		report = false;
4237 	*flavorsp = htonl(supported);
4238 	return 0;
4239 }
4240 
4241 static __be32
4242 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4243 		     struct nfsd4_secinfo *secinfo)
4244 {
4245 	struct xdr_stream *xdr = resp->xdr;
4246 
4247 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4248 }
4249 
4250 static __be32
4251 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4252 		     struct nfsd4_secinfo_no_name *secinfo)
4253 {
4254 	struct xdr_stream *xdr = resp->xdr;
4255 
4256 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4257 }
4258 
4259 /*
4260  * The SETATTR encode routine is special -- it always encodes a bitmap,
4261  * regardless of the error status.
4262  */
4263 static __be32
4264 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
4265 {
4266 	struct xdr_stream *xdr = resp->xdr;
4267 	__be32 *p;
4268 
4269 	p = xdr_reserve_space(xdr, 16);
4270 	if (!p)
4271 		return nfserr_resource;
4272 	if (nfserr) {
4273 		*p++ = cpu_to_be32(3);
4274 		*p++ = cpu_to_be32(0);
4275 		*p++ = cpu_to_be32(0);
4276 		*p++ = cpu_to_be32(0);
4277 	}
4278 	else {
4279 		*p++ = cpu_to_be32(3);
4280 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
4281 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
4282 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
4283 	}
4284 	return nfserr;
4285 }
4286 
4287 static __be32
4288 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
4289 {
4290 	struct xdr_stream *xdr = resp->xdr;
4291 	__be32 *p;
4292 
4293 	if (!nfserr) {
4294 		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
4295 		if (!p)
4296 			return nfserr_resource;
4297 		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
4298 		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
4299 						NFS4_VERIFIER_SIZE);
4300 	}
4301 	else if (nfserr == nfserr_clid_inuse) {
4302 		p = xdr_reserve_space(xdr, 8);
4303 		if (!p)
4304 			return nfserr_resource;
4305 		*p++ = cpu_to_be32(0);
4306 		*p++ = cpu_to_be32(0);
4307 	}
4308 	return nfserr;
4309 }
4310 
4311 static __be32
4312 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
4313 {
4314 	struct xdr_stream *xdr = resp->xdr;
4315 	__be32 *p;
4316 
4317 	p = xdr_reserve_space(xdr, 16);
4318 	if (!p)
4319 		return nfserr_resource;
4320 	*p++ = cpu_to_be32(write->wr_bytes_written);
4321 	*p++ = cpu_to_be32(write->wr_how_written);
4322 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4323 						NFS4_VERIFIER_SIZE);
4324 	return 0;
4325 }
4326 
4327 static __be32
4328 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4329 			 struct nfsd4_exchange_id *exid)
4330 {
4331 	struct xdr_stream *xdr = resp->xdr;
4332 	__be32 *p;
4333 	char *major_id;
4334 	char *server_scope;
4335 	int major_id_sz;
4336 	int server_scope_sz;
4337 	uint64_t minor_id = 0;
4338 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4339 
4340 	major_id = nn->nfsd_name;
4341 	major_id_sz = strlen(nn->nfsd_name);
4342 	server_scope = nn->nfsd_name;
4343 	server_scope_sz = strlen(nn->nfsd_name);
4344 
4345 	p = xdr_reserve_space(xdr,
4346 		8 /* eir_clientid */ +
4347 		4 /* eir_sequenceid */ +
4348 		4 /* eir_flags */ +
4349 		4 /* spr_how */);
4350 	if (!p)
4351 		return nfserr_resource;
4352 
4353 	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
4354 	*p++ = cpu_to_be32(exid->seqid);
4355 	*p++ = cpu_to_be32(exid->flags);
4356 
4357 	*p++ = cpu_to_be32(exid->spa_how);
4358 
4359 	switch (exid->spa_how) {
4360 	case SP4_NONE:
4361 		break;
4362 	case SP4_MACH_CRED:
4363 		/* spo_must_enforce bitmap: */
4364 		nfserr = nfsd4_encode_bitmap(xdr,
4365 					exid->spo_must_enforce[0],
4366 					exid->spo_must_enforce[1],
4367 					exid->spo_must_enforce[2]);
4368 		if (nfserr)
4369 			return nfserr;
4370 		/* spo_must_allow bitmap: */
4371 		nfserr = nfsd4_encode_bitmap(xdr,
4372 					exid->spo_must_allow[0],
4373 					exid->spo_must_allow[1],
4374 					exid->spo_must_allow[2]);
4375 		if (nfserr)
4376 			return nfserr;
4377 		break;
4378 	default:
4379 		WARN_ON_ONCE(1);
4380 	}
4381 
4382 	p = xdr_reserve_space(xdr,
4383 		8 /* so_minor_id */ +
4384 		4 /* so_major_id.len */ +
4385 		(XDR_QUADLEN(major_id_sz) * 4) +
4386 		4 /* eir_server_scope.len */ +
4387 		(XDR_QUADLEN(server_scope_sz) * 4) +
4388 		4 /* eir_server_impl_id.count (0) */);
4389 	if (!p)
4390 		return nfserr_resource;
4391 
4392 	/* The server_owner struct */
4393 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
4394 	/* major id */
4395 	p = xdr_encode_opaque(p, major_id, major_id_sz);
4396 
4397 	/* Server scope */
4398 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
4399 
4400 	/* Implementation id */
4401 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
4402 	return 0;
4403 }
4404 
4405 static __be32
4406 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4407 			    struct nfsd4_create_session *sess)
4408 {
4409 	struct xdr_stream *xdr = resp->xdr;
4410 	__be32 *p;
4411 
4412 	p = xdr_reserve_space(xdr, 24);
4413 	if (!p)
4414 		return nfserr_resource;
4415 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
4416 					NFS4_MAX_SESSIONID_LEN);
4417 	*p++ = cpu_to_be32(sess->seqid);
4418 	*p++ = cpu_to_be32(sess->flags);
4419 
4420 	p = xdr_reserve_space(xdr, 28);
4421 	if (!p)
4422 		return nfserr_resource;
4423 	*p++ = cpu_to_be32(0); /* headerpadsz */
4424 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
4425 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
4426 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
4427 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4428 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4429 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4430 
4431 	if (sess->fore_channel.nr_rdma_attrs) {
4432 		p = xdr_reserve_space(xdr, 4);
4433 		if (!p)
4434 			return nfserr_resource;
4435 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4436 	}
4437 
4438 	p = xdr_reserve_space(xdr, 28);
4439 	if (!p)
4440 		return nfserr_resource;
4441 	*p++ = cpu_to_be32(0); /* headerpadsz */
4442 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4443 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4444 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4445 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4446 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4447 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4448 
4449 	if (sess->back_channel.nr_rdma_attrs) {
4450 		p = xdr_reserve_space(xdr, 4);
4451 		if (!p)
4452 			return nfserr_resource;
4453 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4454 	}
4455 	return 0;
4456 }
4457 
4458 static __be32
4459 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4460 		      struct nfsd4_sequence *seq)
4461 {
4462 	struct xdr_stream *xdr = resp->xdr;
4463 	__be32 *p;
4464 
4465 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4466 	if (!p)
4467 		return nfserr_resource;
4468 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4469 					NFS4_MAX_SESSIONID_LEN);
4470 	*p++ = cpu_to_be32(seq->seqid);
4471 	*p++ = cpu_to_be32(seq->slotid);
4472 	/* Note slotid's are numbered from zero: */
4473 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4474 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4475 	*p++ = cpu_to_be32(seq->status_flags);
4476 
4477 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4478 	return 0;
4479 }
4480 
4481 static __be32
4482 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4483 			  struct nfsd4_test_stateid *test_stateid)
4484 {
4485 	struct xdr_stream *xdr = resp->xdr;
4486 	struct nfsd4_test_stateid_id *stateid, *next;
4487 	__be32 *p;
4488 
4489 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4490 	if (!p)
4491 		return nfserr_resource;
4492 	*p++ = htonl(test_stateid->ts_num_ids);
4493 
4494 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4495 		*p++ = stateid->ts_id_status;
4496 	}
4497 
4498 	return 0;
4499 }
4500 
4501 #ifdef CONFIG_NFSD_PNFS
4502 static __be32
4503 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4504 		struct nfsd4_getdeviceinfo *gdev)
4505 {
4506 	struct xdr_stream *xdr = resp->xdr;
4507 	const struct nfsd4_layout_ops *ops;
4508 	u32 starting_len = xdr->buf->len, needed_len;
4509 	__be32 *p;
4510 
4511 	p = xdr_reserve_space(xdr, 4);
4512 	if (!p)
4513 		return nfserr_resource;
4514 
4515 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4516 
4517 	/* If maxcount is 0 then just update notifications */
4518 	if (gdev->gd_maxcount != 0) {
4519 		ops = nfsd4_layout_ops[gdev->gd_layout_type];
4520 		nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4521 		if (nfserr) {
4522 			/*
4523 			 * We don't bother to burden the layout drivers with
4524 			 * enforcing gd_maxcount, just tell the client to
4525 			 * come back with a bigger buffer if it's not enough.
4526 			 */
4527 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
4528 				goto toosmall;
4529 			return nfserr;
4530 		}
4531 	}
4532 
4533 	if (gdev->gd_notify_types) {
4534 		p = xdr_reserve_space(xdr, 4 + 4);
4535 		if (!p)
4536 			return nfserr_resource;
4537 		*p++ = cpu_to_be32(1);			/* bitmap length */
4538 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4539 	} else {
4540 		p = xdr_reserve_space(xdr, 4);
4541 		if (!p)
4542 			return nfserr_resource;
4543 		*p++ = 0;
4544 	}
4545 
4546 	return 0;
4547 toosmall:
4548 	dprintk("%s: maxcount too small\n", __func__);
4549 	needed_len = xdr->buf->len + 4 /* notifications */;
4550 	xdr_truncate_encode(xdr, starting_len);
4551 	p = xdr_reserve_space(xdr, 4);
4552 	if (!p)
4553 		return nfserr_resource;
4554 	*p++ = cpu_to_be32(needed_len);
4555 	return nfserr_toosmall;
4556 }
4557 
4558 static __be32
4559 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4560 		struct nfsd4_layoutget *lgp)
4561 {
4562 	struct xdr_stream *xdr = resp->xdr;
4563 	const struct nfsd4_layout_ops *ops;
4564 	__be32 *p;
4565 
4566 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4567 	if (!p)
4568 		return nfserr_resource;
4569 
4570 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4571 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4572 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4573 				    sizeof(stateid_opaque_t));
4574 
4575 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4576 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4577 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4578 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4579 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4580 
4581 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4582 	return ops->encode_layoutget(xdr, lgp);
4583 }
4584 
4585 static __be32
4586 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4587 			  struct nfsd4_layoutcommit *lcp)
4588 {
4589 	struct xdr_stream *xdr = resp->xdr;
4590 	__be32 *p;
4591 
4592 	p = xdr_reserve_space(xdr, 4);
4593 	if (!p)
4594 		return nfserr_resource;
4595 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4596 	if (lcp->lc_size_chg) {
4597 		p = xdr_reserve_space(xdr, 8);
4598 		if (!p)
4599 			return nfserr_resource;
4600 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4601 	}
4602 
4603 	return 0;
4604 }
4605 
4606 static __be32
4607 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4608 		struct nfsd4_layoutreturn *lrp)
4609 {
4610 	struct xdr_stream *xdr = resp->xdr;
4611 	__be32 *p;
4612 
4613 	p = xdr_reserve_space(xdr, 4);
4614 	if (!p)
4615 		return nfserr_resource;
4616 	*p++ = cpu_to_be32(lrp->lrs_present);
4617 	if (lrp->lrs_present)
4618 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4619 	return 0;
4620 }
4621 #endif /* CONFIG_NFSD_PNFS */
4622 
4623 static __be32
4624 nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
4625 		struct nfsd42_write_res *write, bool sync)
4626 {
4627 	__be32 *p;
4628 	p = xdr_reserve_space(resp->xdr, 4);
4629 	if (!p)
4630 		return nfserr_resource;
4631 
4632 	if (sync)
4633 		*p++ = cpu_to_be32(0);
4634 	else {
4635 		__be32 nfserr;
4636 		*p++ = cpu_to_be32(1);
4637 		nfserr = nfsd4_encode_stateid(resp->xdr, &write->cb_stateid);
4638 		if (nfserr)
4639 			return nfserr;
4640 	}
4641 	p = xdr_reserve_space(resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
4642 	if (!p)
4643 		return nfserr_resource;
4644 
4645 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4646 	*p++ = cpu_to_be32(write->wr_stable_how);
4647 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4648 				    NFS4_VERIFIER_SIZE);
4649 	return nfs_ok;
4650 }
4651 
4652 static __be32
4653 nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
4654 {
4655 	struct xdr_stream *xdr = resp->xdr;
4656 	struct nfs42_netaddr *addr;
4657 	__be32 *p;
4658 
4659 	p = xdr_reserve_space(xdr, 4);
4660 	*p++ = cpu_to_be32(ns->nl4_type);
4661 
4662 	switch (ns->nl4_type) {
4663 	case NL4_NETADDR:
4664 		addr = &ns->u.nl4_addr;
4665 
4666 		/* netid_len, netid, uaddr_len, uaddr (port included
4667 		 * in RPCBIND_MAXUADDRLEN)
4668 		 */
4669 		p = xdr_reserve_space(xdr,
4670 			4 /* netid len */ +
4671 			(XDR_QUADLEN(addr->netid_len) * 4) +
4672 			4 /* uaddr len */ +
4673 			(XDR_QUADLEN(addr->addr_len) * 4));
4674 		if (!p)
4675 			return nfserr_resource;
4676 
4677 		*p++ = cpu_to_be32(addr->netid_len);
4678 		p = xdr_encode_opaque_fixed(p, addr->netid,
4679 					    addr->netid_len);
4680 		*p++ = cpu_to_be32(addr->addr_len);
4681 		p = xdr_encode_opaque_fixed(p, addr->addr,
4682 					addr->addr_len);
4683 		break;
4684 	default:
4685 		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
4686 		return nfserr_inval;
4687 	}
4688 
4689 	return 0;
4690 }
4691 
4692 static __be32
4693 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4694 		  struct nfsd4_copy *copy)
4695 {
4696 	__be32 *p;
4697 
4698 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
4699 					 !!copy->cp_synchronous);
4700 	if (nfserr)
4701 		return nfserr;
4702 
4703 	p = xdr_reserve_space(resp->xdr, 4 + 4);
4704 	*p++ = xdr_one; /* cr_consecutive */
4705 	*p++ = cpu_to_be32(copy->cp_synchronous);
4706 	return 0;
4707 }
4708 
4709 static __be32
4710 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
4711 			    struct nfsd4_offload_status *os)
4712 {
4713 	struct xdr_stream *xdr = resp->xdr;
4714 	__be32 *p;
4715 
4716 	p = xdr_reserve_space(xdr, 8 + 4);
4717 	if (!p)
4718 		return nfserr_resource;
4719 	p = xdr_encode_hyper(p, os->count);
4720 	*p++ = cpu_to_be32(0);
4721 	return nfserr;
4722 }
4723 
4724 static __be32
4725 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
4726 			    struct nfsd4_read *read,
4727 			    unsigned long *maxcount, u32 *eof,
4728 			    loff_t *pos)
4729 {
4730 	struct xdr_stream *xdr = resp->xdr;
4731 	struct file *file = read->rd_nf->nf_file;
4732 	int starting_len = xdr->buf->len;
4733 	loff_t hole_pos;
4734 	__be32 nfserr;
4735 	__be32 *p, tmp;
4736 	__be64 tmp64;
4737 
4738 	hole_pos = pos ? *pos : vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4739 	if (hole_pos > read->rd_offset)
4740 		*maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
4741 	*maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
4742 
4743 	/* Content type, offset, byte count */
4744 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
4745 	if (!p)
4746 		return nfserr_resource;
4747 
4748 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
4749 	if (read->rd_vlen < 0)
4750 		return nfserr_resource;
4751 
4752 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
4753 			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
4754 	if (nfserr)
4755 		return nfserr;
4756 	xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
4757 
4758 	tmp = htonl(NFS4_CONTENT_DATA);
4759 	write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
4760 	tmp64 = cpu_to_be64(read->rd_offset);
4761 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
4762 	tmp = htonl(*maxcount);
4763 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
4764 
4765 	tmp = xdr_zero;
4766 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
4767 			       xdr_pad_size(*maxcount));
4768 	return nfs_ok;
4769 }
4770 
4771 static __be32
4772 nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
4773 			    struct nfsd4_read *read,
4774 			    unsigned long *maxcount, u32 *eof)
4775 {
4776 	struct file *file = read->rd_nf->nf_file;
4777 	loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
4778 	loff_t f_size = i_size_read(file_inode(file));
4779 	unsigned long count;
4780 	__be32 *p;
4781 
4782 	if (data_pos == -ENXIO)
4783 		data_pos = f_size;
4784 	else if (data_pos <= read->rd_offset || (data_pos < f_size && data_pos % PAGE_SIZE))
4785 		return nfsd4_encode_read_plus_data(resp, read, maxcount, eof, &f_size);
4786 	count = data_pos - read->rd_offset;
4787 
4788 	/* Content type, offset, byte count */
4789 	p = xdr_reserve_space(resp->xdr, 4 + 8 + 8);
4790 	if (!p)
4791 		return nfserr_resource;
4792 
4793 	*p++ = htonl(NFS4_CONTENT_HOLE);
4794 	p = xdr_encode_hyper(p, read->rd_offset);
4795 	p = xdr_encode_hyper(p, count);
4796 
4797 	*eof = (read->rd_offset + count) >= f_size;
4798 	*maxcount = min_t(unsigned long, count, *maxcount);
4799 	return nfs_ok;
4800 }
4801 
4802 static __be32
4803 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
4804 		       struct nfsd4_read *read)
4805 {
4806 	unsigned long maxcount, count;
4807 	struct xdr_stream *xdr = resp->xdr;
4808 	struct file *file;
4809 	int starting_len = xdr->buf->len;
4810 	int last_segment = xdr->buf->len;
4811 	int segments = 0;
4812 	__be32 *p, tmp;
4813 	bool is_data;
4814 	loff_t pos;
4815 	u32 eof;
4816 
4817 	if (nfserr)
4818 		return nfserr;
4819 	file = read->rd_nf->nf_file;
4820 
4821 	/* eof flag, segment count */
4822 	p = xdr_reserve_space(xdr, 4 + 4);
4823 	if (!p)
4824 		return nfserr_resource;
4825 	xdr_commit_encode(xdr);
4826 
4827 	maxcount = min_t(unsigned long, read->rd_length,
4828 			 (xdr->buf->buflen - xdr->buf->len));
4829 	count    = maxcount;
4830 
4831 	eof = read->rd_offset >= i_size_read(file_inode(file));
4832 	if (eof)
4833 		goto out;
4834 
4835 	pos = vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4836 	is_data = pos > read->rd_offset;
4837 
4838 	while (count > 0 && !eof) {
4839 		maxcount = count;
4840 		if (is_data)
4841 			nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof,
4842 						segments == 0 ? &pos : NULL);
4843 		else
4844 			nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
4845 		if (nfserr)
4846 			goto out;
4847 		count -= maxcount;
4848 		read->rd_offset += maxcount;
4849 		is_data = !is_data;
4850 		last_segment = xdr->buf->len;
4851 		segments++;
4852 	}
4853 
4854 out:
4855 	if (nfserr && segments == 0)
4856 		xdr_truncate_encode(xdr, starting_len);
4857 	else {
4858 		if (nfserr) {
4859 			xdr_truncate_encode(xdr, last_segment);
4860 			nfserr = nfs_ok;
4861 			eof = 0;
4862 		}
4863 		tmp = htonl(eof);
4864 		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
4865 		tmp = htonl(segments);
4866 		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
4867 	}
4868 
4869 	return nfserr;
4870 }
4871 
4872 static __be32
4873 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
4874 			 struct nfsd4_copy_notify *cn)
4875 {
4876 	struct xdr_stream *xdr = resp->xdr;
4877 	__be32 *p;
4878 
4879 	if (nfserr)
4880 		return nfserr;
4881 
4882 	/* 8 sec, 4 nsec */
4883 	p = xdr_reserve_space(xdr, 12);
4884 	if (!p)
4885 		return nfserr_resource;
4886 
4887 	/* cnr_lease_time */
4888 	p = xdr_encode_hyper(p, cn->cpn_sec);
4889 	*p++ = cpu_to_be32(cn->cpn_nsec);
4890 
4891 	/* cnr_stateid */
4892 	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
4893 	if (nfserr)
4894 		return nfserr;
4895 
4896 	/* cnr_src.nl_nsvr */
4897 	p = xdr_reserve_space(xdr, 4);
4898 	if (!p)
4899 		return nfserr_resource;
4900 
4901 	*p++ = cpu_to_be32(1);
4902 
4903 	return nfsd42_encode_nl4_server(resp, &cn->cpn_src);
4904 }
4905 
4906 static __be32
4907 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
4908 		  struct nfsd4_seek *seek)
4909 {
4910 	__be32 *p;
4911 
4912 	p = xdr_reserve_space(resp->xdr, 4 + 8);
4913 	*p++ = cpu_to_be32(seek->seek_eof);
4914 	p = xdr_encode_hyper(p, seek->seek_pos);
4915 
4916 	return 0;
4917 }
4918 
4919 static __be32
4920 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
4921 {
4922 	return nfserr;
4923 }
4924 
4925 /*
4926  * Encode kmalloc-ed buffer in to XDR stream.
4927  */
4928 static __be32
4929 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
4930 {
4931 	u32 cplen;
4932 	__be32 *p;
4933 
4934 	cplen = min_t(unsigned long, buflen,
4935 		      ((void *)xdr->end - (void *)xdr->p));
4936 	p = xdr_reserve_space(xdr, cplen);
4937 	if (!p)
4938 		return nfserr_resource;
4939 
4940 	memcpy(p, buf, cplen);
4941 	buf += cplen;
4942 	buflen -= cplen;
4943 
4944 	while (buflen) {
4945 		cplen = min_t(u32, buflen, PAGE_SIZE);
4946 		p = xdr_reserve_space(xdr, cplen);
4947 		if (!p)
4948 			return nfserr_resource;
4949 
4950 		memcpy(p, buf, cplen);
4951 
4952 		if (cplen < PAGE_SIZE) {
4953 			/*
4954 			 * We're done, with a length that wasn't page
4955 			 * aligned, so possibly not word aligned. Pad
4956 			 * any trailing bytes with 0.
4957 			 */
4958 			xdr_encode_opaque_fixed(p, NULL, cplen);
4959 			break;
4960 		}
4961 
4962 		buflen -= PAGE_SIZE;
4963 		buf += PAGE_SIZE;
4964 	}
4965 
4966 	return 0;
4967 }
4968 
4969 static __be32
4970 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4971 		      struct nfsd4_getxattr *getxattr)
4972 {
4973 	struct xdr_stream *xdr = resp->xdr;
4974 	__be32 *p, err;
4975 
4976 	p = xdr_reserve_space(xdr, 4);
4977 	if (!p)
4978 		return nfserr_resource;
4979 
4980 	*p = cpu_to_be32(getxattr->getxa_len);
4981 
4982 	if (getxattr->getxa_len == 0)
4983 		return 0;
4984 
4985 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
4986 				    getxattr->getxa_len);
4987 
4988 	kvfree(getxattr->getxa_buf);
4989 
4990 	return err;
4991 }
4992 
4993 static __be32
4994 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4995 		      struct nfsd4_setxattr *setxattr)
4996 {
4997 	struct xdr_stream *xdr = resp->xdr;
4998 	__be32 *p;
4999 
5000 	p = xdr_reserve_space(xdr, 20);
5001 	if (!p)
5002 		return nfserr_resource;
5003 
5004 	encode_cinfo(p, &setxattr->setxa_cinfo);
5005 
5006 	return 0;
5007 }
5008 
5009 /*
5010  * See if there are cookie values that can be rejected outright.
5011  */
5012 static __be32
5013 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5014 				u32 *offsetp)
5015 {
5016 	u64 cookie = listxattrs->lsxa_cookie;
5017 
5018 	/*
5019 	 * If the cookie is larger than the maximum number we can fit
5020 	 * in either the buffer we just got back from vfs_listxattr, or,
5021 	 * XDR-encoded, in the return buffer, it's invalid.
5022 	 */
5023 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5024 		return nfserr_badcookie;
5025 
5026 	if (cookie > (listxattrs->lsxa_maxcount /
5027 		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
5028 		return nfserr_badcookie;
5029 
5030 	*offsetp = (u32)cookie;
5031 	return 0;
5032 }
5033 
5034 static __be32
5035 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5036 			struct nfsd4_listxattrs *listxattrs)
5037 {
5038 	struct xdr_stream *xdr = resp->xdr;
5039 	u32 cookie_offset, count_offset, eof;
5040 	u32 left, xdrleft, slen, count;
5041 	u32 xdrlen, offset;
5042 	u64 cookie;
5043 	char *sp;
5044 	__be32 status, tmp;
5045 	__be32 *p;
5046 	u32 nuser;
5047 
5048 	eof = 1;
5049 
5050 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5051 	if (status)
5052 		goto out;
5053 
5054 	/*
5055 	 * Reserve space for the cookie and the name array count. Record
5056 	 * the offsets to save them later.
5057 	 */
5058 	cookie_offset = xdr->buf->len;
5059 	count_offset = cookie_offset + 8;
5060 	p = xdr_reserve_space(xdr, 12);
5061 	if (!p) {
5062 		status = nfserr_resource;
5063 		goto out;
5064 	}
5065 
5066 	count = 0;
5067 	left = listxattrs->lsxa_len;
5068 	sp = listxattrs->lsxa_buf;
5069 	nuser = 0;
5070 
5071 	xdrleft = listxattrs->lsxa_maxcount;
5072 
5073 	while (left > 0 && xdrleft > 0) {
5074 		slen = strlen(sp);
5075 
5076 		/*
5077 		 * Check if this is a "user." attribute, skip it if not.
5078 		 */
5079 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5080 			goto contloop;
5081 
5082 		slen -= XATTR_USER_PREFIX_LEN;
5083 		xdrlen = 4 + ((slen + 3) & ~3);
5084 		if (xdrlen > xdrleft) {
5085 			if (count == 0) {
5086 				/*
5087 				 * Can't even fit the first attribute name.
5088 				 */
5089 				status = nfserr_toosmall;
5090 				goto out;
5091 			}
5092 			eof = 0;
5093 			goto wreof;
5094 		}
5095 
5096 		left -= XATTR_USER_PREFIX_LEN;
5097 		sp += XATTR_USER_PREFIX_LEN;
5098 		if (nuser++ < offset)
5099 			goto contloop;
5100 
5101 
5102 		p = xdr_reserve_space(xdr, xdrlen);
5103 		if (!p) {
5104 			status = nfserr_resource;
5105 			goto out;
5106 		}
5107 
5108 		xdr_encode_opaque(p, sp, slen);
5109 
5110 		xdrleft -= xdrlen;
5111 		count++;
5112 contloop:
5113 		sp += slen + 1;
5114 		left -= slen + 1;
5115 	}
5116 
5117 	/*
5118 	 * If there were user attributes to copy, but we didn't copy
5119 	 * any, the offset was too large (e.g. the cookie was invalid).
5120 	 */
5121 	if (nuser > 0 && count == 0) {
5122 		status = nfserr_badcookie;
5123 		goto out;
5124 	}
5125 
5126 wreof:
5127 	p = xdr_reserve_space(xdr, 4);
5128 	if (!p) {
5129 		status = nfserr_resource;
5130 		goto out;
5131 	}
5132 	*p = cpu_to_be32(eof);
5133 
5134 	cookie = offset + count;
5135 
5136 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
5137 	tmp = cpu_to_be32(count);
5138 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5139 out:
5140 	if (listxattrs->lsxa_len)
5141 		kvfree(listxattrs->lsxa_buf);
5142 	return status;
5143 }
5144 
5145 static __be32
5146 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5147 			 struct nfsd4_removexattr *removexattr)
5148 {
5149 	struct xdr_stream *xdr = resp->xdr;
5150 	__be32 *p;
5151 
5152 	p = xdr_reserve_space(xdr, 20);
5153 	if (!p)
5154 		return nfserr_resource;
5155 
5156 	p = encode_cinfo(p, &removexattr->rmxa_cinfo);
5157 	return 0;
5158 }
5159 
5160 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
5161 
5162 /*
5163  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5164  * since we don't need to filter out obsolete ops as this is
5165  * done in the decoding phase.
5166  */
5167 static const nfsd4_enc nfsd4_enc_ops[] = {
5168 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
5169 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
5170 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
5171 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
5172 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
5173 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5174 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
5175 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
5176 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
5177 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
5178 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
5179 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
5180 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
5181 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
5182 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5183 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
5184 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
5185 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
5186 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
5187 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5188 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
5189 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5190 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
5191 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
5192 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
5193 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
5194 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
5195 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
5196 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
5197 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
5198 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
5199 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
5200 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
5201 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
5202 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5203 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
5204 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
5205 
5206 	/* NFSv4.1 operations */
5207 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
5208 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
5209 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
5210 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
5211 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
5212 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
5213 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5214 #ifdef CONFIG_NFSD_PNFS
5215 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
5216 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5217 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
5218 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
5219 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
5220 #else
5221 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
5222 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5223 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
5224 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
5225 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5226 #endif
5227 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
5228 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
5229 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
5230 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
5231 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5232 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
5233 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
5234 
5235 	/* NFSv4.2 operations */
5236 	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5237 	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
5238 	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_copy_notify,
5239 	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5240 	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
5241 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
5242 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
5243 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
5244 	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
5245 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_read_plus,
5246 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
5247 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
5248 	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
5249 
5250 	/* RFC 8276 extended atributes operations */
5251 	[OP_GETXATTR]		= (nfsd4_enc)nfsd4_encode_getxattr,
5252 	[OP_SETXATTR]		= (nfsd4_enc)nfsd4_encode_setxattr,
5253 	[OP_LISTXATTRS]		= (nfsd4_enc)nfsd4_encode_listxattrs,
5254 	[OP_REMOVEXATTR]	= (nfsd4_enc)nfsd4_encode_removexattr,
5255 };
5256 
5257 /*
5258  * Calculate whether we still have space to encode repsize bytes.
5259  * There are two considerations:
5260  *     - For NFS versions >=4.1, the size of the reply must stay within
5261  *       session limits
5262  *     - For all NFS versions, we must stay within limited preallocated
5263  *       buffer space.
5264  *
5265  * This is called before the operation is processed, so can only provide
5266  * an upper estimate.  For some nonidempotent operations (such as
5267  * getattr), it's not necessarily a problem if that estimate is wrong,
5268  * as we can fail it after processing without significant side effects.
5269  */
5270 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5271 {
5272 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5273 	struct nfsd4_slot *slot = resp->cstate.slot;
5274 
5275 	if (buf->len + respsize <= buf->buflen)
5276 		return nfs_ok;
5277 	if (!nfsd4_has_session(&resp->cstate))
5278 		return nfserr_resource;
5279 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5280 		WARN_ON_ONCE(1);
5281 		return nfserr_rep_too_big_to_cache;
5282 	}
5283 	return nfserr_rep_too_big;
5284 }
5285 
5286 void
5287 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5288 {
5289 	struct xdr_stream *xdr = resp->xdr;
5290 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5291 	struct svc_rqst *rqstp = resp->rqstp;
5292 	const struct nfsd4_operation *opdesc = op->opdesc;
5293 	int post_err_offset;
5294 	nfsd4_enc encoder;
5295 	__be32 *p;
5296 
5297 	p = xdr_reserve_space(xdr, 8);
5298 	if (!p) {
5299 		WARN_ON_ONCE(1);
5300 		return;
5301 	}
5302 	*p++ = cpu_to_be32(op->opnum);
5303 	post_err_offset = xdr->buf->len;
5304 
5305 	if (op->opnum == OP_ILLEGAL)
5306 		goto status;
5307 	if (op->status && opdesc &&
5308 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5309 		goto status;
5310 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5311 	       !nfsd4_enc_ops[op->opnum]);
5312 	encoder = nfsd4_enc_ops[op->opnum];
5313 	op->status = encoder(resp, op->status, &op->u);
5314 	if (op->status)
5315 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5316 	if (opdesc && opdesc->op_release)
5317 		opdesc->op_release(&op->u);
5318 	xdr_commit_encode(xdr);
5319 
5320 	/* nfsd4_check_resp_size guarantees enough room for error status */
5321 	if (!op->status) {
5322 		int space_needed = 0;
5323 		if (!nfsd4_last_compound_op(rqstp))
5324 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5325 		op->status = nfsd4_check_resp_size(resp, space_needed);
5326 	}
5327 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5328 		struct nfsd4_slot *slot = resp->cstate.slot;
5329 
5330 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5331 			op->status = nfserr_rep_too_big_to_cache;
5332 		else
5333 			op->status = nfserr_rep_too_big;
5334 	}
5335 	if (op->status == nfserr_resource ||
5336 	    op->status == nfserr_rep_too_big ||
5337 	    op->status == nfserr_rep_too_big_to_cache) {
5338 		/*
5339 		 * The operation may have already been encoded or
5340 		 * partially encoded.  No op returns anything additional
5341 		 * in the case of one of these three errors, so we can
5342 		 * just truncate back to after the status.  But it's a
5343 		 * bug if we had to do this on a non-idempotent op:
5344 		 */
5345 		warn_on_nonidempotent_op(op);
5346 		xdr_truncate_encode(xdr, post_err_offset);
5347 	}
5348 	if (so) {
5349 		int len = xdr->buf->len - post_err_offset;
5350 
5351 		so->so_replay.rp_status = op->status;
5352 		so->so_replay.rp_buflen = len;
5353 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5354 						so->so_replay.rp_buf, len);
5355 	}
5356 status:
5357 	/* Note that op->status is already in network byte order: */
5358 	write_bytes_to_xdr_buf(xdr->buf, post_err_offset - 4, &op->status, 4);
5359 }
5360 
5361 /*
5362  * Encode the reply stored in the stateowner reply cache
5363  *
5364  * XDR note: do not encode rp->rp_buflen: the buffer contains the
5365  * previously sent already encoded operation.
5366  */
5367 void
5368 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5369 {
5370 	__be32 *p;
5371 	struct nfs4_replay *rp = op->replay;
5372 
5373 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
5374 	if (!p) {
5375 		WARN_ON_ONCE(1);
5376 		return;
5377 	}
5378 	*p++ = cpu_to_be32(op->opnum);
5379 	*p++ = rp->rp_status;  /* already xdr'ed */
5380 
5381 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
5382 }
5383 
5384 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5385 {
5386 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5387 
5388 	if (args->ops != args->iops) {
5389 		kfree(args->ops);
5390 		args->ops = args->iops;
5391 	}
5392 	while (args->to_free) {
5393 		struct svcxdr_tmpbuf *tb = args->to_free;
5394 		args->to_free = tb->next;
5395 		kfree(tb);
5396 	}
5397 }
5398 
5399 bool
5400 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5401 {
5402 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5403 
5404 	/* svcxdr_tmp_alloc */
5405 	args->to_free = NULL;
5406 
5407 	args->xdr = xdr;
5408 	args->ops = args->iops;
5409 	args->rqstp = rqstp;
5410 
5411 	return nfsd4_decode_compound(args);
5412 }
5413 
5414 bool
5415 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5416 {
5417 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5418 	struct xdr_buf *buf = xdr->buf;
5419 	__be32 *p;
5420 
5421 	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
5422 				 buf->tail[0].iov_len);
5423 
5424 	/*
5425 	 * Send buffer space for the following items is reserved
5426 	 * at the top of nfsd4_proc_compound().
5427 	 */
5428 	p = resp->statusp;
5429 
5430 	*p++ = resp->cstate.status;
5431 
5432 	rqstp->rq_next_page = xdr->page_ptr + 1;
5433 
5434 	*p++ = htonl(resp->taglen);
5435 	memcpy(p, resp->tag, resp->taglen);
5436 	p += XDR_QUADLEN(resp->taglen);
5437 	*p++ = htonl(resp->opcnt);
5438 
5439 	nfsd4_sequence_done(resp);
5440 	return true;
5441 }
5442