xref: /openbmc/linux/fs/nfsd/nfs4xdr.c (revision de6da33e)
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 	u32 i, count;
281 	__be32 *p;
282 
283 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
284 		return nfserr_bad_xdr;
285 	/* request sanity */
286 	if (count > 1000)
287 		return nfserr_bad_xdr;
288 	p = xdr_inline_decode(argp->xdr, count << 2);
289 	if (!p)
290 		return nfserr_bad_xdr;
291 	i = 0;
292 	while (i < count)
293 		bmval[i++] = be32_to_cpup(p++);
294 	while (i < bmlen)
295 		bmval[i++] = 0;
296 
297 	return nfs_ok;
298 }
299 
300 static __be32
301 nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
302 {
303 	__be32 *p, status;
304 	u32 length;
305 
306 	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
307 		return nfserr_bad_xdr;
308 	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
309 		return nfserr_bad_xdr;
310 	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
311 		return nfserr_bad_xdr;
312 
313 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
314 		return nfserr_bad_xdr;
315 	p = xdr_inline_decode(argp->xdr, length);
316 	if (!p)
317 		return nfserr_bad_xdr;
318 	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
319 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
320 		status = nfs_ok;
321 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
322 		status = nfsd_map_name_to_gid(argp->rqstp,
323 				(char *)p, length, &ace->who_gid);
324 	else
325 		status = nfsd_map_name_to_uid(argp->rqstp,
326 				(char *)p, length, &ace->who_uid);
327 
328 	return status;
329 }
330 
331 /* A counted array of nfsace4's */
332 static noinline __be32
333 nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
334 {
335 	struct nfs4_ace *ace;
336 	__be32 status;
337 	u32 count;
338 
339 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
340 		return nfserr_bad_xdr;
341 
342 	if (count > xdr_stream_remaining(argp->xdr) / 20)
343 		/*
344 		 * Even with 4-byte names there wouldn't be
345 		 * space for that many aces; something fishy is
346 		 * going on:
347 		 */
348 		return nfserr_fbig;
349 
350 	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
351 	if (*acl == NULL)
352 		return nfserr_jukebox;
353 
354 	(*acl)->naces = count;
355 	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
356 		status = nfsd4_decode_nfsace4(argp, ace);
357 		if (status)
358 			return status;
359 	}
360 
361 	return nfs_ok;
362 }
363 
364 static noinline __be32
365 nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
366 			    struct xdr_netobj *label)
367 {
368 	u32 lfs, pi, length;
369 	__be32 *p;
370 
371 	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
372 		return nfserr_bad_xdr;
373 	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
374 		return nfserr_bad_xdr;
375 
376 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
377 		return nfserr_bad_xdr;
378 	if (length > NFS4_MAXLABELLEN)
379 		return nfserr_badlabel;
380 	p = xdr_inline_decode(argp->xdr, length);
381 	if (!p)
382 		return nfserr_bad_xdr;
383 	label->len = length;
384 	label->data = svcxdr_dupstr(argp, p, length);
385 	if (!label->data)
386 		return nfserr_jukebox;
387 
388 	return nfs_ok;
389 }
390 
391 static __be32
392 nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
393 		    struct iattr *iattr, struct nfs4_acl **acl,
394 		    struct xdr_netobj *label, int *umask)
395 {
396 	unsigned int starting_pos;
397 	u32 attrlist4_count;
398 	__be32 *p, status;
399 
400 	iattr->ia_valid = 0;
401 	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
402 	if (status)
403 		return nfserr_bad_xdr;
404 
405 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
406 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
407 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
408 		if (nfsd_attrs_supported(argp->minorversion, bmval))
409 			return nfserr_inval;
410 		return nfserr_attrnotsupp;
411 	}
412 
413 	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
414 		return nfserr_bad_xdr;
415 	starting_pos = xdr_stream_pos(argp->xdr);
416 
417 	if (bmval[0] & FATTR4_WORD0_SIZE) {
418 		u64 size;
419 
420 		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
421 			return nfserr_bad_xdr;
422 		iattr->ia_size = size;
423 		iattr->ia_valid |= ATTR_SIZE;
424 	}
425 	if (bmval[0] & FATTR4_WORD0_ACL) {
426 		status = nfsd4_decode_acl(argp, acl);
427 		if (status)
428 			return status;
429 	} else
430 		*acl = NULL;
431 	if (bmval[1] & FATTR4_WORD1_MODE) {
432 		u32 mode;
433 
434 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
435 			return nfserr_bad_xdr;
436 		iattr->ia_mode = mode;
437 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
438 		iattr->ia_valid |= ATTR_MODE;
439 	}
440 	if (bmval[1] & FATTR4_WORD1_OWNER) {
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_uid(argp->rqstp, (char *)p, length,
449 					      &iattr->ia_uid);
450 		if (status)
451 			return status;
452 		iattr->ia_valid |= ATTR_UID;
453 	}
454 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
455 		u32 length;
456 
457 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
458 			return nfserr_bad_xdr;
459 		p = xdr_inline_decode(argp->xdr, length);
460 		if (!p)
461 			return nfserr_bad_xdr;
462 		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
463 					      &iattr->ia_gid);
464 		if (status)
465 			return status;
466 		iattr->ia_valid |= ATTR_GID;
467 	}
468 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
469 		u32 set_it;
470 
471 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
472 			return nfserr_bad_xdr;
473 		switch (set_it) {
474 		case NFS4_SET_TO_CLIENT_TIME:
475 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
476 			if (status)
477 				return status;
478 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
479 			break;
480 		case NFS4_SET_TO_SERVER_TIME:
481 			iattr->ia_valid |= ATTR_ATIME;
482 			break;
483 		default:
484 			return nfserr_bad_xdr;
485 		}
486 	}
487 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
488 		u32 set_it;
489 
490 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
491 			return nfserr_bad_xdr;
492 		switch (set_it) {
493 		case NFS4_SET_TO_CLIENT_TIME:
494 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
495 			if (status)
496 				return status;
497 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
498 			break;
499 		case NFS4_SET_TO_SERVER_TIME:
500 			iattr->ia_valid |= ATTR_MTIME;
501 			break;
502 		default:
503 			return nfserr_bad_xdr;
504 		}
505 	}
506 	label->len = 0;
507 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
508 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
509 		status = nfsd4_decode_security_label(argp, label);
510 		if (status)
511 			return status;
512 	}
513 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
514 		u32 mode, mask;
515 
516 		if (!umask)
517 			return nfserr_bad_xdr;
518 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
519 			return nfserr_bad_xdr;
520 		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
521 		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
522 			return nfserr_bad_xdr;
523 		*umask = mask & S_IRWXUGO;
524 		iattr->ia_valid |= ATTR_MODE;
525 	}
526 
527 	/* request sanity: did attrlist4 contain the expected number of words? */
528 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
529 		return nfserr_bad_xdr;
530 
531 	return nfs_ok;
532 }
533 
534 static __be32
535 nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
536 {
537 	__be32 *p;
538 
539 	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
540 	if (!p)
541 		return nfserr_bad_xdr;
542 	sid->si_generation = be32_to_cpup(p++);
543 	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
544 	return nfs_ok;
545 }
546 
547 static __be32
548 nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
549 {
550 	__be32 *p;
551 
552 	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
553 	if (!p)
554 		return nfserr_bad_xdr;
555 	memcpy(clientid, p, sizeof(*clientid));
556 	return nfs_ok;
557 }
558 
559 static __be32
560 nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
561 			  clientid_t *clientid, struct xdr_netobj *owner)
562 {
563 	__be32 status;
564 
565 	status = nfsd4_decode_clientid4(argp, clientid);
566 	if (status)
567 		return status;
568 	return nfsd4_decode_opaque(argp, owner);
569 }
570 
571 #ifdef CONFIG_NFSD_PNFS
572 static __be32
573 nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
574 		       struct nfsd4_deviceid *devid)
575 {
576 	__be32 *p;
577 
578 	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
579 	if (!p)
580 		return nfserr_bad_xdr;
581 	memcpy(devid, p, sizeof(*devid));
582 	return nfs_ok;
583 }
584 
585 static __be32
586 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
587 			   struct nfsd4_layoutcommit *lcp)
588 {
589 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
590 		return nfserr_bad_xdr;
591 	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
592 		return nfserr_bad_xdr;
593 	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
594 		return nfserr_bad_xdr;
595 
596 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
597 		return nfserr_bad_xdr;
598 	if (lcp->lc_up_len > 0) {
599 		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
600 		if (!lcp->lc_up_layout)
601 			return nfserr_bad_xdr;
602 	}
603 
604 	return nfs_ok;
605 }
606 
607 static __be32
608 nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
609 			   struct nfsd4_layoutreturn *lrp)
610 {
611 	__be32 status;
612 
613 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
614 		return nfserr_bad_xdr;
615 	switch (lrp->lr_return_type) {
616 	case RETURN_FILE:
617 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
618 			return nfserr_bad_xdr;
619 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
620 			return nfserr_bad_xdr;
621 		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
622 		if (status)
623 			return status;
624 		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
625 			return nfserr_bad_xdr;
626 		if (lrp->lrf_body_len > 0) {
627 			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
628 			if (!lrp->lrf_body)
629 				return nfserr_bad_xdr;
630 		}
631 		break;
632 	case RETURN_FSID:
633 	case RETURN_ALL:
634 		lrp->lr_seg.offset = 0;
635 		lrp->lr_seg.length = NFS4_MAX_UINT64;
636 		break;
637 	default:
638 		return nfserr_bad_xdr;
639 	}
640 
641 	return nfs_ok;
642 }
643 
644 #endif /* CONFIG_NFSD_PNFS */
645 
646 static __be32
647 nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
648 			struct nfs4_sessionid *sessionid)
649 {
650 	__be32 *p;
651 
652 	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
653 	if (!p)
654 		return nfserr_bad_xdr;
655 	memcpy(sessionid->data, p, sizeof(sessionid->data));
656 	return nfs_ok;
657 }
658 
659 /* Defined in Appendix A of RFC 5531 */
660 static __be32
661 nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
662 			   struct nfsd4_cb_sec *cbs)
663 {
664 	u32 stamp, gidcount, uid, gid;
665 	__be32 *p, status;
666 
667 	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
668 		return nfserr_bad_xdr;
669 	/* machine name */
670 	status = nfsd4_decode_ignored_string(argp, 255);
671 	if (status)
672 		return status;
673 	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
674 		return nfserr_bad_xdr;
675 	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
676 		return nfserr_bad_xdr;
677 	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
678 		return nfserr_bad_xdr;
679 	if (gidcount > 16)
680 		return nfserr_bad_xdr;
681 	p = xdr_inline_decode(argp->xdr, gidcount << 2);
682 	if (!p)
683 		return nfserr_bad_xdr;
684 	if (cbs->flavor == (u32)(-1)) {
685 		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
686 
687 		kuid_t kuid = make_kuid(userns, uid);
688 		kgid_t kgid = make_kgid(userns, gid);
689 		if (uid_valid(kuid) && gid_valid(kgid)) {
690 			cbs->uid = kuid;
691 			cbs->gid = kgid;
692 			cbs->flavor = RPC_AUTH_UNIX;
693 		} else {
694 			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
695 		}
696 	}
697 
698 	return nfs_ok;
699 }
700 
701 static __be32
702 nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
703 			     struct nfsd4_cb_sec *cbs)
704 {
705 	__be32 status;
706 	u32 service;
707 
708 	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
709 
710 	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
711 		return nfserr_bad_xdr;
712 	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
713 		return nfserr_bad_xdr;
714 	/* gcbp_handle_from_server */
715 	status = nfsd4_decode_ignored_string(argp, 0);
716 	if (status)
717 		return status;
718 	/* gcbp_handle_from_client */
719 	status = nfsd4_decode_ignored_string(argp, 0);
720 	if (status)
721 		return status;
722 
723 	return nfs_ok;
724 }
725 
726 /* a counted array of callback_sec_parms4 items */
727 static __be32
728 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
729 {
730 	u32 i, secflavor, nr_secflavs;
731 	__be32 status;
732 
733 	/* callback_sec_params4 */
734 	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
735 		return nfserr_bad_xdr;
736 	if (nr_secflavs)
737 		cbs->flavor = (u32)(-1);
738 	else
739 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
740 		cbs->flavor = 0;
741 
742 	for (i = 0; i < nr_secflavs; ++i) {
743 		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
744 			return nfserr_bad_xdr;
745 		switch (secflavor) {
746 		case RPC_AUTH_NULL:
747 			/* void */
748 			if (cbs->flavor == (u32)(-1))
749 				cbs->flavor = RPC_AUTH_NULL;
750 			break;
751 		case RPC_AUTH_UNIX:
752 			status = nfsd4_decode_authsys_parms(argp, cbs);
753 			if (status)
754 				return status;
755 			break;
756 		case RPC_AUTH_GSS:
757 			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
758 			if (status)
759 				return status;
760 			break;
761 		default:
762 			return nfserr_inval;
763 		}
764 	}
765 
766 	return nfs_ok;
767 }
768 
769 
770 /*
771  * NFSv4 operation argument decoders
772  */
773 
774 static __be32
775 nfsd4_decode_access(struct nfsd4_compoundargs *argp,
776 		    struct nfsd4_access *access)
777 {
778 	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
779 		return nfserr_bad_xdr;
780 	return nfs_ok;
781 }
782 
783 static __be32
784 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
785 {
786 	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
787 		return nfserr_bad_xdr;
788 	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
789 }
790 
791 
792 static __be32
793 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
794 {
795 	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
796 		return nfserr_bad_xdr;
797 	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
798 		return nfserr_bad_xdr;
799 	return nfs_ok;
800 }
801 
802 static __be32
803 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
804 {
805 	__be32 *p, status;
806 
807 	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
808 		return nfserr_bad_xdr;
809 	switch (create->cr_type) {
810 	case NF4LNK:
811 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
812 			return nfserr_bad_xdr;
813 		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
814 		if (!p)
815 			return nfserr_bad_xdr;
816 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
817 		if (!create->cr_data)
818 			return nfserr_jukebox;
819 		break;
820 	case NF4BLK:
821 	case NF4CHR:
822 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
823 			return nfserr_bad_xdr;
824 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
825 			return nfserr_bad_xdr;
826 		break;
827 	case NF4SOCK:
828 	case NF4FIFO:
829 	case NF4DIR:
830 	default:
831 		break;
832 	}
833 	status = nfsd4_decode_component4(argp, &create->cr_name,
834 					 &create->cr_namelen);
835 	if (status)
836 		return status;
837 	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
838 				    ARRAY_SIZE(create->cr_bmval),
839 				    &create->cr_iattr, &create->cr_acl,
840 				    &create->cr_label, &create->cr_umask);
841 	if (status)
842 		return status;
843 
844 	return nfs_ok;
845 }
846 
847 static inline __be32
848 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
849 {
850 	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
851 }
852 
853 static inline __be32
854 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
855 {
856 	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
857 				    ARRAY_SIZE(getattr->ga_bmval));
858 }
859 
860 static __be32
861 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
862 {
863 	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
864 }
865 
866 static __be32
867 nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
868 				 struct nfsd4_lock *lock)
869 {
870 	__be32 status;
871 
872 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
873 		return nfserr_bad_xdr;
874 	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
875 	if (status)
876 		return status;
877 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
878 		return nfserr_bad_xdr;
879 	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
880 					 &lock->lk_new_owner);
881 }
882 
883 static __be32
884 nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
885 			       struct nfsd4_lock *lock)
886 {
887 	__be32 status;
888 
889 	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
890 	if (status)
891 		return status;
892 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
893 		return nfserr_bad_xdr;
894 
895 	return nfs_ok;
896 }
897 
898 static __be32
899 nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
900 {
901 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
902 		return nfserr_bad_xdr;
903 	if (lock->lk_is_new)
904 		return nfsd4_decode_open_to_lock_owner4(argp, lock);
905 	return nfsd4_decode_exist_lock_owner4(argp, lock);
906 }
907 
908 static __be32
909 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
910 {
911 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
912 		return nfserr_bad_xdr;
913 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
914 		return nfserr_bad_xdr;
915 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
916 		return nfserr_bad_xdr;
917 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
918 		return nfserr_bad_xdr;
919 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
920 		return nfserr_bad_xdr;
921 	return nfsd4_decode_locker4(argp, lock);
922 }
923 
924 static __be32
925 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
926 {
927 	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
928 		return nfserr_bad_xdr;
929 	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
930 		return nfserr_bad_xdr;
931 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
932 		return nfserr_bad_xdr;
933 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
934 		return nfserr_bad_xdr;
935 	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
936 					 &lockt->lt_owner);
937 }
938 
939 static __be32
940 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
941 {
942 	__be32 status;
943 
944 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
945 		return nfserr_bad_xdr;
946 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
947 		return nfserr_bad_xdr;
948 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
949 		return nfserr_bad_xdr;
950 	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
951 	if (status)
952 		return status;
953 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
954 		return nfserr_bad_xdr;
955 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
956 		return nfserr_bad_xdr;
957 
958 	return nfs_ok;
959 }
960 
961 static __be32
962 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
963 {
964 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
965 }
966 
967 static __be32
968 nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
969 {
970 	__be32 status;
971 
972 	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
973 		return nfserr_bad_xdr;
974 	switch (open->op_createmode) {
975 	case NFS4_CREATE_UNCHECKED:
976 	case NFS4_CREATE_GUARDED:
977 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
978 					     ARRAY_SIZE(open->op_bmval),
979 					     &open->op_iattr, &open->op_acl,
980 					     &open->op_label, &open->op_umask);
981 		if (status)
982 			return status;
983 		break;
984 	case NFS4_CREATE_EXCLUSIVE:
985 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
986 		if (status)
987 			return status;
988 		break;
989 	case NFS4_CREATE_EXCLUSIVE4_1:
990 		if (argp->minorversion < 1)
991 			return nfserr_bad_xdr;
992 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
993 		if (status)
994 			return status;
995 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
996 					     ARRAY_SIZE(open->op_bmval),
997 					     &open->op_iattr, &open->op_acl,
998 					     &open->op_label, &open->op_umask);
999 		if (status)
1000 			return status;
1001 		break;
1002 	default:
1003 		return nfserr_bad_xdr;
1004 	}
1005 
1006 	return nfs_ok;
1007 }
1008 
1009 static __be32
1010 nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1011 {
1012 	__be32 status;
1013 
1014 	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
1015 		return nfserr_bad_xdr;
1016 	switch (open->op_create) {
1017 	case NFS4_OPEN_NOCREATE:
1018 		break;
1019 	case NFS4_OPEN_CREATE:
1020 		status = nfsd4_decode_createhow4(argp, open);
1021 		if (status)
1022 			return status;
1023 		break;
1024 	default:
1025 		return nfserr_bad_xdr;
1026 	}
1027 
1028 	return nfs_ok;
1029 }
1030 
1031 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
1032 {
1033 	u32 w;
1034 
1035 	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
1036 		return nfserr_bad_xdr;
1037 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
1038 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
1039 	if (deleg_when)
1040 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
1041 
1042 	switch (w & NFS4_SHARE_ACCESS_MASK) {
1043 	case NFS4_SHARE_ACCESS_READ:
1044 	case NFS4_SHARE_ACCESS_WRITE:
1045 	case NFS4_SHARE_ACCESS_BOTH:
1046 		break;
1047 	default:
1048 		return nfserr_bad_xdr;
1049 	}
1050 	w &= ~NFS4_SHARE_ACCESS_MASK;
1051 	if (!w)
1052 		return nfs_ok;
1053 	if (!argp->minorversion)
1054 		return nfserr_bad_xdr;
1055 	switch (w & NFS4_SHARE_WANT_MASK) {
1056 	case NFS4_SHARE_WANT_NO_PREFERENCE:
1057 	case NFS4_SHARE_WANT_READ_DELEG:
1058 	case NFS4_SHARE_WANT_WRITE_DELEG:
1059 	case NFS4_SHARE_WANT_ANY_DELEG:
1060 	case NFS4_SHARE_WANT_NO_DELEG:
1061 	case NFS4_SHARE_WANT_CANCEL:
1062 		break;
1063 	default:
1064 		return nfserr_bad_xdr;
1065 	}
1066 	w &= ~NFS4_SHARE_WANT_MASK;
1067 	if (!w)
1068 		return nfs_ok;
1069 
1070 	if (!deleg_when)	/* open_downgrade */
1071 		return nfserr_inval;
1072 	switch (w) {
1073 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
1074 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
1075 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
1076 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
1077 		return nfs_ok;
1078 	}
1079 	return nfserr_bad_xdr;
1080 }
1081 
1082 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
1083 {
1084 	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
1085 		return nfserr_bad_xdr;
1086 	/* Note: unlike access bits, deny bits may be zero. */
1087 	if (*x & ~NFS4_SHARE_DENY_BOTH)
1088 		return nfserr_bad_xdr;
1089 
1090 	return nfs_ok;
1091 }
1092 
1093 static __be32
1094 nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
1095 			 struct nfsd4_open *open)
1096 {
1097 	__be32 status;
1098 
1099 	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
1100 		return nfserr_bad_xdr;
1101 	switch (open->op_claim_type) {
1102 	case NFS4_OPEN_CLAIM_NULL:
1103 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
1104 		status = nfsd4_decode_component4(argp, &open->op_fname,
1105 						 &open->op_fnamelen);
1106 		if (status)
1107 			return status;
1108 		break;
1109 	case NFS4_OPEN_CLAIM_PREVIOUS:
1110 		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
1111 			return nfserr_bad_xdr;
1112 		break;
1113 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
1114 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1115 		if (status)
1116 			return status;
1117 		status = nfsd4_decode_component4(argp, &open->op_fname,
1118 						 &open->op_fnamelen);
1119 		if (status)
1120 			return status;
1121 		break;
1122 	case NFS4_OPEN_CLAIM_FH:
1123 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1124 		if (argp->minorversion < 1)
1125 			return nfserr_bad_xdr;
1126 		/* void */
1127 		break;
1128 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1129 		if (argp->minorversion < 1)
1130 			return nfserr_bad_xdr;
1131 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1132 		if (status)
1133 			return status;
1134 		break;
1135 	default:
1136 		return nfserr_bad_xdr;
1137 	}
1138 
1139 	return nfs_ok;
1140 }
1141 
1142 static __be32
1143 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1144 {
1145 	__be32 status;
1146 	u32 dummy;
1147 
1148 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
1149 	open->op_iattr.ia_valid = 0;
1150 	open->op_openowner = NULL;
1151 
1152 	open->op_xdr_error = 0;
1153 	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
1154 		return nfserr_bad_xdr;
1155 	/* deleg_want is ignored */
1156 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
1157 					   &open->op_deleg_want, &dummy);
1158 	if (status)
1159 		return status;
1160 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
1161 	if (status)
1162 		return status;
1163 	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
1164 					   &open->op_owner);
1165 	if (status)
1166 		return status;
1167 	status = nfsd4_decode_openflag4(argp, open);
1168 	if (status)
1169 		return status;
1170 	return nfsd4_decode_open_claim4(argp, open);
1171 }
1172 
1173 static __be32
1174 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
1175 {
1176 	__be32 status;
1177 
1178 	if (argp->minorversion >= 1)
1179 		return nfserr_notsupp;
1180 
1181 	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
1182 	if (status)
1183 		return status;
1184 	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
1185 		return nfserr_bad_xdr;
1186 
1187 	return nfs_ok;
1188 }
1189 
1190 static __be32
1191 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
1192 {
1193 	__be32 status;
1194 
1195 	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
1196 	if (status)
1197 		return status;
1198 	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
1199 		return nfserr_bad_xdr;
1200 	/* deleg_want is ignored */
1201 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1202 					   &open_down->od_deleg_want, NULL);
1203 	if (status)
1204 		return status;
1205 	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1206 }
1207 
1208 static __be32
1209 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
1210 {
1211 	__be32 *p;
1212 
1213 	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
1214 		return nfserr_bad_xdr;
1215 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1216 		return nfserr_bad_xdr;
1217 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
1218 	if (!p)
1219 		return nfserr_bad_xdr;
1220 	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
1221 	if (!putfh->pf_fhval)
1222 		return nfserr_jukebox;
1223 
1224 	return nfs_ok;
1225 }
1226 
1227 static __be32
1228 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
1229 {
1230 	if (argp->minorversion == 0)
1231 		return nfs_ok;
1232 	return nfserr_notsupp;
1233 }
1234 
1235 static __be32
1236 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
1237 {
1238 	__be32 status;
1239 
1240 	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
1241 	if (status)
1242 		return status;
1243 	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
1244 		return nfserr_bad_xdr;
1245 	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
1246 		return nfserr_bad_xdr;
1247 
1248 	return nfs_ok;
1249 }
1250 
1251 static __be32
1252 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
1253 {
1254 	__be32 status;
1255 
1256 	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
1257 		return nfserr_bad_xdr;
1258 	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
1259 	if (status)
1260 		return status;
1261 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
1262 		return nfserr_bad_xdr;
1263 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
1264 		return nfserr_bad_xdr;
1265 	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
1266 					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
1267 		return nfserr_bad_xdr;
1268 
1269 	return nfs_ok;
1270 }
1271 
1272 static __be32
1273 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
1274 {
1275 	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
1276 }
1277 
1278 static __be32
1279 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
1280 {
1281 	__be32 status;
1282 
1283 	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
1284 	if (status)
1285 		return status;
1286 	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
1287 }
1288 
1289 static __be32
1290 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
1291 {
1292 	return nfsd4_decode_clientid4(argp, clientid);
1293 }
1294 
1295 static __be32
1296 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1297 		     struct nfsd4_secinfo *secinfo)
1298 {
1299 	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
1300 }
1301 
1302 static __be32
1303 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
1304 {
1305 	__be32 status;
1306 
1307 	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
1308 	if (status)
1309 		return status;
1310 	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
1311 				   ARRAY_SIZE(setattr->sa_bmval),
1312 				   &setattr->sa_iattr, &setattr->sa_acl,
1313 				   &setattr->sa_label, NULL);
1314 }
1315 
1316 static __be32
1317 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
1318 {
1319 	__be32 *p, status;
1320 
1321 	if (argp->minorversion >= 1)
1322 		return nfserr_notsupp;
1323 
1324 	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
1325 	if (status)
1326 		return status;
1327 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1328 	if (status)
1329 		return status;
1330 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
1331 		return nfserr_bad_xdr;
1332 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
1333 		return nfserr_bad_xdr;
1334 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
1335 	if (!p)
1336 		return nfserr_bad_xdr;
1337 	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
1338 						setclientid->se_callback_netid_len);
1339 	if (!setclientid->se_callback_netid_val)
1340 		return nfserr_jukebox;
1341 
1342 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
1343 		return nfserr_bad_xdr;
1344 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
1345 	if (!p)
1346 		return nfserr_bad_xdr;
1347 	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
1348 						setclientid->se_callback_addr_len);
1349 	if (!setclientid->se_callback_addr_val)
1350 		return nfserr_jukebox;
1351 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
1352 		return nfserr_bad_xdr;
1353 
1354 	return nfs_ok;
1355 }
1356 
1357 static __be32
1358 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1359 {
1360 	__be32 status;
1361 
1362 	if (argp->minorversion >= 1)
1363 		return nfserr_notsupp;
1364 
1365 	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
1366 	if (status)
1367 		return status;
1368 	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
1369 }
1370 
1371 /* Also used for NVERIFY */
1372 static __be32
1373 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1374 {
1375 	__be32 *p, status;
1376 
1377 	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
1378 				      ARRAY_SIZE(verify->ve_bmval));
1379 	if (status)
1380 		return status;
1381 
1382 	/* For convenience's sake, we compare raw xdr'd attributes in
1383 	 * nfsd4_proc_verify */
1384 
1385 	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
1386 		return nfserr_bad_xdr;
1387 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
1388 	if (!p)
1389 		return nfserr_bad_xdr;
1390 	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
1391 	if (!verify->ve_attrval)
1392 		return nfserr_jukebox;
1393 
1394 	return nfs_ok;
1395 }
1396 
1397 static __be32
1398 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1399 {
1400 	__be32 status;
1401 
1402 	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
1403 	if (status)
1404 		return status;
1405 	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
1406 		return nfserr_bad_xdr;
1407 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
1408 		return nfserr_bad_xdr;
1409 	if (write->wr_stable_how > NFS_FILE_SYNC)
1410 		return nfserr_bad_xdr;
1411 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
1412 		return nfserr_bad_xdr;
1413 	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
1414 		return nfserr_bad_xdr;
1415 
1416 	return nfs_ok;
1417 }
1418 
1419 static __be32
1420 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1421 {
1422 	__be32 status;
1423 
1424 	if (argp->minorversion >= 1)
1425 		return nfserr_notsupp;
1426 
1427 	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
1428 					   &rlockowner->rl_owner);
1429 	if (status)
1430 		return status;
1431 
1432 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1433 		return nfserr_inval;
1434 
1435 	return nfs_ok;
1436 }
1437 
1438 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
1439 {
1440 	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
1441 		return nfserr_bad_xdr;
1442 	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
1443 }
1444 
1445 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
1446 {
1447 	u32 use_conn_in_rdma_mode;
1448 	__be32 status;
1449 
1450 	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
1451 	if (status)
1452 		return status;
1453 	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
1454 		return nfserr_bad_xdr;
1455 	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
1456 		return nfserr_bad_xdr;
1457 
1458 	return nfs_ok;
1459 }
1460 
1461 static __be32
1462 nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
1463 			       struct nfsd4_exchange_id *exid)
1464 {
1465 	__be32 status;
1466 
1467 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
1468 				      ARRAY_SIZE(exid->spo_must_enforce));
1469 	if (status)
1470 		return nfserr_bad_xdr;
1471 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
1472 				      ARRAY_SIZE(exid->spo_must_allow));
1473 	if (status)
1474 		return nfserr_bad_xdr;
1475 
1476 	return nfs_ok;
1477 }
1478 
1479 /*
1480  * This implementation currently does not support SP4_SSV.
1481  * This decoder simply skips over these arguments.
1482  */
1483 static noinline __be32
1484 nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
1485 			  struct nfsd4_exchange_id *exid)
1486 {
1487 	u32 count, window, num_gss_handles;
1488 	__be32 status;
1489 
1490 	/* ssp_ops */
1491 	status = nfsd4_decode_state_protect_ops(argp, exid);
1492 	if (status)
1493 		return status;
1494 
1495 	/* ssp_hash_algs<> */
1496 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1497 		return nfserr_bad_xdr;
1498 	while (count--) {
1499 		status = nfsd4_decode_ignored_string(argp, 0);
1500 		if (status)
1501 			return status;
1502 	}
1503 
1504 	/* ssp_encr_algs<> */
1505 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1506 		return nfserr_bad_xdr;
1507 	while (count--) {
1508 		status = nfsd4_decode_ignored_string(argp, 0);
1509 		if (status)
1510 			return status;
1511 	}
1512 
1513 	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
1514 		return nfserr_bad_xdr;
1515 	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
1516 		return nfserr_bad_xdr;
1517 
1518 	return nfs_ok;
1519 }
1520 
1521 static __be32
1522 nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
1523 			      struct nfsd4_exchange_id *exid)
1524 {
1525 	__be32 status;
1526 
1527 	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
1528 		return nfserr_bad_xdr;
1529 	switch (exid->spa_how) {
1530 	case SP4_NONE:
1531 		break;
1532 	case SP4_MACH_CRED:
1533 		status = nfsd4_decode_state_protect_ops(argp, exid);
1534 		if (status)
1535 			return status;
1536 		break;
1537 	case SP4_SSV:
1538 		status = nfsd4_decode_ssv_sp_parms(argp, exid);
1539 		if (status)
1540 			return status;
1541 		break;
1542 	default:
1543 		return nfserr_bad_xdr;
1544 	}
1545 
1546 	return nfs_ok;
1547 }
1548 
1549 static __be32
1550 nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
1551 			  struct nfsd4_exchange_id *exid)
1552 {
1553 	__be32 status;
1554 	u32 count;
1555 
1556 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1557 		return nfserr_bad_xdr;
1558 	switch (count) {
1559 	case 0:
1560 		break;
1561 	case 1:
1562 		/* Note that RFC 8881 places no length limit on
1563 		 * nii_domain, but this implementation permits no
1564 		 * more than NFS4_OPAQUE_LIMIT bytes */
1565 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1566 		if (status)
1567 			return status;
1568 		/* Note that RFC 8881 places no length limit on
1569 		 * nii_name, but this implementation permits no
1570 		 * more than NFS4_OPAQUE_LIMIT bytes */
1571 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1572 		if (status)
1573 			return status;
1574 		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
1575 		if (status)
1576 			return status;
1577 		break;
1578 	default:
1579 		return nfserr_bad_xdr;
1580 	}
1581 
1582 	return nfs_ok;
1583 }
1584 
1585 static __be32
1586 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1587 			 struct nfsd4_exchange_id *exid)
1588 {
1589 	__be32 status;
1590 
1591 	status = nfsd4_decode_verifier4(argp, &exid->verifier);
1592 	if (status)
1593 		return status;
1594 	status = nfsd4_decode_opaque(argp, &exid->clname);
1595 	if (status)
1596 		return status;
1597 	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
1598 		return nfserr_bad_xdr;
1599 	status = nfsd4_decode_state_protect4_a(argp, exid);
1600 	if (status)
1601 		return status;
1602 	return nfsd4_decode_nfs_impl_id4(argp, exid);
1603 }
1604 
1605 static __be32
1606 nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
1607 			    struct nfsd4_channel_attrs *ca)
1608 {
1609 	__be32 *p;
1610 
1611 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
1612 	if (!p)
1613 		return nfserr_bad_xdr;
1614 
1615 	/* headerpadsz is ignored */
1616 	p++;
1617 	ca->maxreq_sz = be32_to_cpup(p++);
1618 	ca->maxresp_sz = be32_to_cpup(p++);
1619 	ca->maxresp_cached = be32_to_cpup(p++);
1620 	ca->maxops = be32_to_cpup(p++);
1621 	ca->maxreqs = be32_to_cpup(p++);
1622 	ca->nr_rdma_attrs = be32_to_cpup(p);
1623 	switch (ca->nr_rdma_attrs) {
1624 	case 0:
1625 		break;
1626 	case 1:
1627 		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
1628 			return nfserr_bad_xdr;
1629 		break;
1630 	default:
1631 		return nfserr_bad_xdr;
1632 	}
1633 
1634 	return nfs_ok;
1635 }
1636 
1637 static __be32
1638 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1639 			    struct nfsd4_create_session *sess)
1640 {
1641 	__be32 status;
1642 
1643 	status = nfsd4_decode_clientid4(argp, &sess->clientid);
1644 	if (status)
1645 		return status;
1646 	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
1647 		return nfserr_bad_xdr;
1648 	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
1649 		return nfserr_bad_xdr;
1650 	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
1651 	if (status)
1652 		return status;
1653 	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
1654 	if (status)
1655 		return status;
1656 	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
1657 		return nfserr_bad_xdr;
1658 	status = nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1659 	if (status)
1660 		return status;
1661 
1662 	return nfs_ok;
1663 }
1664 
1665 static __be32
1666 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1667 			     struct nfsd4_destroy_session *destroy_session)
1668 {
1669 	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
1670 }
1671 
1672 static __be32
1673 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1674 			  struct nfsd4_free_stateid *free_stateid)
1675 {
1676 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
1677 }
1678 
1679 #ifdef CONFIG_NFSD_PNFS
1680 static __be32
1681 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1682 		struct nfsd4_getdeviceinfo *gdev)
1683 {
1684 	__be32 status;
1685 
1686 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1687 	if (status)
1688 		return status;
1689 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1690 		return nfserr_bad_xdr;
1691 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1692 		return nfserr_bad_xdr;
1693 	if (xdr_stream_decode_uint32_array(argp->xdr,
1694 					   &gdev->gd_notify_types, 1) < 0)
1695 		return nfserr_bad_xdr;
1696 
1697 	return nfs_ok;
1698 }
1699 
1700 static __be32
1701 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1702 			  struct nfsd4_layoutcommit *lcp)
1703 {
1704 	__be32 *p, status;
1705 
1706 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1707 		return nfserr_bad_xdr;
1708 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1709 		return nfserr_bad_xdr;
1710 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1711 		return nfserr_bad_xdr;
1712 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1713 	if (status)
1714 		return status;
1715 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1716 		return nfserr_bad_xdr;
1717 	if (lcp->lc_newoffset) {
1718 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1719 			return nfserr_bad_xdr;
1720 	} else
1721 		lcp->lc_last_wr = 0;
1722 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1723 	if (!p)
1724 		return nfserr_bad_xdr;
1725 	if (xdr_item_is_present(p)) {
1726 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1727 		if (status)
1728 			return status;
1729 	} else {
1730 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1731 	}
1732 	return nfsd4_decode_layoutupdate4(argp, lcp);
1733 }
1734 
1735 static __be32
1736 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1737 		struct nfsd4_layoutget *lgp)
1738 {
1739 	__be32 status;
1740 
1741 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1742 		return nfserr_bad_xdr;
1743 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1744 		return nfserr_bad_xdr;
1745 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1746 		return nfserr_bad_xdr;
1747 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1748 		return nfserr_bad_xdr;
1749 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1750 		return nfserr_bad_xdr;
1751 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1752 		return nfserr_bad_xdr;
1753 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1754 	if (status)
1755 		return status;
1756 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1757 		return nfserr_bad_xdr;
1758 
1759 	return nfs_ok;
1760 }
1761 
1762 static __be32
1763 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1764 		struct nfsd4_layoutreturn *lrp)
1765 {
1766 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1767 		return nfserr_bad_xdr;
1768 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1769 		return nfserr_bad_xdr;
1770 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1771 		return nfserr_bad_xdr;
1772 	return nfsd4_decode_layoutreturn4(argp, lrp);
1773 }
1774 #endif /* CONFIG_NFSD_PNFS */
1775 
1776 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1777 					   struct nfsd4_secinfo_no_name *sin)
1778 {
1779 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1780 		return nfserr_bad_xdr;
1781 	return nfs_ok;
1782 }
1783 
1784 static __be32
1785 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1786 		      struct nfsd4_sequence *seq)
1787 {
1788 	__be32 *p, status;
1789 
1790 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1791 	if (status)
1792 		return status;
1793 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1794 	if (!p)
1795 		return nfserr_bad_xdr;
1796 	seq->seqid = be32_to_cpup(p++);
1797 	seq->slotid = be32_to_cpup(p++);
1798 	seq->maxslots = be32_to_cpup(p++);
1799 	seq->cachethis = be32_to_cpup(p);
1800 
1801 	return nfs_ok;
1802 }
1803 
1804 static __be32
1805 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1806 {
1807 	struct nfsd4_test_stateid_id *stateid;
1808 	__be32 status;
1809 	u32 i;
1810 
1811 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1812 		return nfserr_bad_xdr;
1813 
1814 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1815 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1816 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1817 		if (!stateid)
1818 			return nfserrno(-ENOMEM);	/* XXX: not jukebox? */
1819 		INIT_LIST_HEAD(&stateid->ts_id_list);
1820 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1821 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1822 		if (status)
1823 			return status;
1824 	}
1825 
1826 	return nfs_ok;
1827 }
1828 
1829 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1830 					    struct nfsd4_destroy_clientid *dc)
1831 {
1832 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1833 }
1834 
1835 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1836 					    struct nfsd4_reclaim_complete *rc)
1837 {
1838 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1839 		return nfserr_bad_xdr;
1840 	return nfs_ok;
1841 }
1842 
1843 static __be32
1844 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1845 		       struct nfsd4_fallocate *fallocate)
1846 {
1847 	__be32 status;
1848 
1849 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1850 	if (status)
1851 		return status;
1852 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1853 		return nfserr_bad_xdr;
1854 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1855 		return nfserr_bad_xdr;
1856 
1857 	return nfs_ok;
1858 }
1859 
1860 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1861 				      struct nl4_server *ns)
1862 {
1863 	struct nfs42_netaddr *naddr;
1864 	__be32 *p;
1865 
1866 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1867 		return nfserr_bad_xdr;
1868 
1869 	/* currently support for 1 inter-server source server */
1870 	switch (ns->nl4_type) {
1871 	case NL4_NETADDR:
1872 		naddr = &ns->u.nl4_addr;
1873 
1874 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1875 			return nfserr_bad_xdr;
1876 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1877 			return nfserr_bad_xdr;
1878 
1879 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1880 		if (!p)
1881 			return nfserr_bad_xdr;
1882 		memcpy(naddr->netid, p, naddr->netid_len);
1883 
1884 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1885 			return nfserr_bad_xdr;
1886 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1887 			return nfserr_bad_xdr;
1888 
1889 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1890 		if (!p)
1891 			return nfserr_bad_xdr;
1892 		memcpy(naddr->addr, p, naddr->addr_len);
1893 		break;
1894 	default:
1895 		return nfserr_bad_xdr;
1896 	}
1897 
1898 	return nfs_ok;
1899 }
1900 
1901 static __be32
1902 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
1903 {
1904 	struct nl4_server *ns_dummy;
1905 	u32 consecutive, i, count;
1906 	__be32 status;
1907 
1908 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
1909 	if (status)
1910 		return status;
1911 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
1912 	if (status)
1913 		return status;
1914 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
1915 		return nfserr_bad_xdr;
1916 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
1917 		return nfserr_bad_xdr;
1918 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
1919 		return nfserr_bad_xdr;
1920 	/* ca_consecutive: we always do consecutive copies */
1921 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
1922 		return nfserr_bad_xdr;
1923 	if (xdr_stream_decode_u32(argp->xdr, &copy->cp_synchronous) < 0)
1924 		return nfserr_bad_xdr;
1925 
1926 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1927 		return nfserr_bad_xdr;
1928 	copy->cp_intra = false;
1929 	if (count == 0) { /* intra-server copy */
1930 		copy->cp_intra = true;
1931 		return nfs_ok;
1932 	}
1933 
1934 	/* decode all the supplied server addresses but use only the first */
1935 	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
1936 	if (status)
1937 		return status;
1938 
1939 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
1940 	if (ns_dummy == NULL)
1941 		return nfserrno(-ENOMEM);	/* XXX: jukebox? */
1942 	for (i = 0; i < count - 1; i++) {
1943 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
1944 		if (status) {
1945 			kfree(ns_dummy);
1946 			return status;
1947 		}
1948 	}
1949 	kfree(ns_dummy);
1950 
1951 	return nfs_ok;
1952 }
1953 
1954 static __be32
1955 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
1956 			 struct nfsd4_copy_notify *cn)
1957 {
1958 	__be32 status;
1959 
1960 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
1961 	if (status)
1962 		return status;
1963 	return nfsd4_decode_nl4_server(argp, &cn->cpn_dst);
1964 }
1965 
1966 static __be32
1967 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
1968 			    struct nfsd4_offload_status *os)
1969 {
1970 	return nfsd4_decode_stateid4(argp, &os->stateid);
1971 }
1972 
1973 static __be32
1974 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
1975 {
1976 	__be32 status;
1977 
1978 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
1979 	if (status)
1980 		return status;
1981 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
1982 		return nfserr_bad_xdr;
1983 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
1984 		return nfserr_bad_xdr;
1985 
1986 	return nfs_ok;
1987 }
1988 
1989 static __be32
1990 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
1991 {
1992 	__be32 status;
1993 
1994 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
1995 	if (status)
1996 		return status;
1997 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
1998 	if (status)
1999 		return status;
2000 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
2001 		return nfserr_bad_xdr;
2002 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
2003 		return nfserr_bad_xdr;
2004 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
2005 		return nfserr_bad_xdr;
2006 
2007 	return nfs_ok;
2008 }
2009 
2010 /*
2011  * XDR data that is more than PAGE_SIZE in size is normally part of a
2012  * read or write. However, the size of extended attributes is limited
2013  * by the maximum request size, and then further limited by the underlying
2014  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2015  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2016  * and we're not dealing with contiguous pages, we need to do some copying.
2017  */
2018 
2019 /*
2020  * Decode data into buffer.
2021  */
2022 static __be32
2023 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2024 		       char **bufp, u32 buflen)
2025 {
2026 	struct page **pages = xdr->pages;
2027 	struct kvec *head = xdr->head;
2028 	char *tmp, *dp;
2029 	u32 len;
2030 
2031 	if (buflen <= head->iov_len) {
2032 		/*
2033 		 * We're in luck, the head has enough space. Just return
2034 		 * the head, no need for copying.
2035 		 */
2036 		*bufp = head->iov_base;
2037 		return 0;
2038 	}
2039 
2040 	tmp = svcxdr_tmpalloc(argp, buflen);
2041 	if (tmp == NULL)
2042 		return nfserr_jukebox;
2043 
2044 	dp = tmp;
2045 	memcpy(dp, head->iov_base, head->iov_len);
2046 	buflen -= head->iov_len;
2047 	dp += head->iov_len;
2048 
2049 	while (buflen > 0) {
2050 		len = min_t(u32, buflen, PAGE_SIZE);
2051 		memcpy(dp, page_address(*pages), len);
2052 
2053 		buflen -= len;
2054 		dp += len;
2055 		pages++;
2056 	}
2057 
2058 	*bufp = tmp;
2059 	return 0;
2060 }
2061 
2062 /*
2063  * Get a user extended attribute name from the XDR buffer.
2064  * It will not have the "user." prefix, so prepend it.
2065  * Lastly, check for nul characters in the name.
2066  */
2067 static __be32
2068 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2069 {
2070 	char *name, *sp, *dp;
2071 	u32 namelen, cnt;
2072 	__be32 *p;
2073 
2074 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2075 		return nfserr_bad_xdr;
2076 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2077 		return nfserr_nametoolong;
2078 	if (namelen == 0)
2079 		return nfserr_bad_xdr;
2080 	p = xdr_inline_decode(argp->xdr, namelen);
2081 	if (!p)
2082 		return nfserr_bad_xdr;
2083 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2084 	if (!name)
2085 		return nfserr_jukebox;
2086 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2087 
2088 	/*
2089 	 * Copy the extended attribute name over while checking for 0
2090 	 * characters.
2091 	 */
2092 	sp = (char *)p;
2093 	dp = name + XATTR_USER_PREFIX_LEN;
2094 	cnt = namelen;
2095 
2096 	while (cnt-- > 0) {
2097 		if (*sp == '\0')
2098 			return nfserr_bad_xdr;
2099 		*dp++ = *sp++;
2100 	}
2101 	*dp = '\0';
2102 
2103 	*namep = name;
2104 
2105 	return nfs_ok;
2106 }
2107 
2108 /*
2109  * A GETXATTR op request comes without a length specifier. We just set the
2110  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2111  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2112  * check it against getxa_len, and allocate + return the value.
2113  */
2114 static __be32
2115 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2116 		      struct nfsd4_getxattr *getxattr)
2117 {
2118 	__be32 status;
2119 	u32 maxcount;
2120 
2121 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2122 	if (status)
2123 		return status;
2124 
2125 	maxcount = svc_max_payload(argp->rqstp);
2126 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2127 
2128 	getxattr->getxa_len = maxcount;
2129 
2130 	return status;
2131 }
2132 
2133 static __be32
2134 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2135 		      struct nfsd4_setxattr *setxattr)
2136 {
2137 	u32 flags, maxcount, size;
2138 	__be32 status;
2139 
2140 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2141 		return nfserr_bad_xdr;
2142 
2143 	if (flags > SETXATTR4_REPLACE)
2144 		return nfserr_inval;
2145 	setxattr->setxa_flags = flags;
2146 
2147 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2148 	if (status)
2149 		return status;
2150 
2151 	maxcount = svc_max_payload(argp->rqstp);
2152 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2153 
2154 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2155 		return nfserr_bad_xdr;
2156 	if (size > maxcount)
2157 		return nfserr_xattr2big;
2158 
2159 	setxattr->setxa_len = size;
2160 	if (size > 0) {
2161 		struct xdr_buf payload;
2162 
2163 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2164 			return nfserr_bad_xdr;
2165 		status = nfsd4_vbuf_from_vector(argp, &payload,
2166 						&setxattr->setxa_buf, size);
2167 	}
2168 
2169 	return nfs_ok;
2170 }
2171 
2172 static __be32
2173 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2174 			struct nfsd4_listxattrs *listxattrs)
2175 {
2176 	u32 maxcount;
2177 
2178 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2179 		return nfserr_bad_xdr;
2180 
2181 	/*
2182 	 * If the cookie  is too large to have even one user.x attribute
2183 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2184 	 */
2185 	if (listxattrs->lsxa_cookie >=
2186 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2187 		return nfserr_badcookie;
2188 
2189 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2190 		return nfserr_bad_xdr;
2191 	if (maxcount < 8)
2192 		/* Always need at least 2 words (length and one character) */
2193 		return nfserr_inval;
2194 
2195 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2196 	listxattrs->lsxa_maxcount = maxcount;
2197 
2198 	return nfs_ok;
2199 }
2200 
2201 static __be32
2202 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2203 			 struct nfsd4_removexattr *removexattr)
2204 {
2205 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2206 }
2207 
2208 static __be32
2209 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
2210 {
2211 	return nfs_ok;
2212 }
2213 
2214 static __be32
2215 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
2216 {
2217 	return nfserr_notsupp;
2218 }
2219 
2220 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
2221 
2222 static const nfsd4_dec nfsd4_dec_ops[] = {
2223 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
2224 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
2225 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
2226 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
2227 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2228 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
2229 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
2230 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
2231 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
2232 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
2233 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
2234 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
2235 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
2236 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
2237 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2238 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
2239 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
2240 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
2241 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
2242 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
2243 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
2244 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
2245 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
2246 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
2247 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
2248 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
2249 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
2250 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
2251 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
2252 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
2253 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
2254 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
2255 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
2256 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
2257 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
2258 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
2259 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
2260 
2261 	/* new operations for NFSv4.1 */
2262 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
2263 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
2264 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
2265 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
2266 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
2267 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
2268 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2269 #ifdef CONFIG_NFSD_PNFS
2270 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
2271 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2272 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
2273 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
2274 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
2275 #else
2276 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
2277 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
2278 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
2279 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
2280 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
2281 #endif
2282 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
2283 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
2284 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
2285 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
2286 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
2287 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
2288 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
2289 
2290 	/* new operations for NFSv4.2 */
2291 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2292 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
2293 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_copy_notify,
2294 	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
2295 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
2296 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
2297 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
2298 	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
2299 	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
2300 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_read,
2301 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
2302 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
2303 	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
2304 	/* RFC 8276 extended atributes operations */
2305 	[OP_GETXATTR]		= (nfsd4_dec)nfsd4_decode_getxattr,
2306 	[OP_SETXATTR]		= (nfsd4_dec)nfsd4_decode_setxattr,
2307 	[OP_LISTXATTRS]		= (nfsd4_dec)nfsd4_decode_listxattrs,
2308 	[OP_REMOVEXATTR]	= (nfsd4_dec)nfsd4_decode_removexattr,
2309 };
2310 
2311 static inline bool
2312 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2313 {
2314 	if (op->opnum < FIRST_NFS4_OP)
2315 		return false;
2316 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2317 		return false;
2318 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2319 		return false;
2320 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2321 		return false;
2322 	return true;
2323 }
2324 
2325 static bool
2326 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2327 {
2328 	struct nfsd4_op *op;
2329 	bool cachethis = false;
2330 	int auth_slack= argp->rqstp->rq_auth_slack;
2331 	int max_reply = auth_slack + 8; /* opcnt, status */
2332 	int readcount = 0;
2333 	int readbytes = 0;
2334 	__be32 *p;
2335 	int i;
2336 
2337 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2338 		return false;
2339 	max_reply += XDR_UNIT;
2340 	argp->tag = NULL;
2341 	if (unlikely(argp->taglen)) {
2342 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2343 			return false;
2344 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2345 		if (!p)
2346 			return false;
2347 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2348 		if (!argp->tag)
2349 			return false;
2350 		max_reply += xdr_align_size(argp->taglen);
2351 	}
2352 
2353 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2354 		return false;
2355 	if (xdr_stream_decode_u32(argp->xdr, &argp->opcnt) < 0)
2356 		return false;
2357 
2358 	/*
2359 	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
2360 	 * here, so we return success at the xdr level so that
2361 	 * nfsd4_proc can handle this is an NFS-level error.
2362 	 */
2363 	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
2364 		return true;
2365 
2366 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2367 		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
2368 		if (!argp->ops) {
2369 			argp->ops = argp->iops;
2370 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
2371 			return false;
2372 		}
2373 	}
2374 
2375 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2376 		argp->opcnt = 0;
2377 
2378 	for (i = 0; i < argp->opcnt; i++) {
2379 		op = &argp->ops[i];
2380 		op->replay = NULL;
2381 
2382 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2383 			return false;
2384 		if (nfsd4_opnum_in_range(argp, op)) {
2385 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2386 			if (op->status != nfs_ok)
2387 				trace_nfsd_compound_decode_err(argp->rqstp,
2388 							       argp->opcnt, i,
2389 							       op->opnum,
2390 							       op->status);
2391 		} else {
2392 			op->opnum = OP_ILLEGAL;
2393 			op->status = nfserr_op_illegal;
2394 		}
2395 		op->opdesc = OPDESC(op);
2396 		/*
2397 		 * We'll try to cache the result in the DRC if any one
2398 		 * op in the compound wants to be cached:
2399 		 */
2400 		cachethis |= nfsd4_cache_this_op(op);
2401 
2402 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2403 			readcount++;
2404 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2405 		} else
2406 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2407 		/*
2408 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2409 		 * (Special case because it will just skip encoding this
2410 		 * if it runs out of xdr buffer space, and it is the only
2411 		 * operation that behaves this way.)
2412 		 */
2413 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2414 			max_reply += NFS4_OPAQUE_LIMIT;
2415 
2416 		if (op->status) {
2417 			argp->opcnt = i+1;
2418 			break;
2419 		}
2420 	}
2421 	/* Sessions make the DRC unnecessary: */
2422 	if (argp->minorversion)
2423 		cachethis = false;
2424 	svc_reserve(argp->rqstp, max_reply + readbytes);
2425 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2426 
2427 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2428 		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
2429 
2430 	return true;
2431 }
2432 
2433 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
2434 			     struct svc_export *exp)
2435 {
2436 	if (exp->ex_flags & NFSEXP_V4ROOT) {
2437 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
2438 		*p++ = 0;
2439 	} else
2440 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2441 	return p;
2442 }
2443 
2444 /*
2445  * ctime (in NFSv4, time_metadata) is not writeable, and the client
2446  * doesn't really care what resolution could theoretically be stored by
2447  * the filesystem.
2448  *
2449  * The client cares how close together changes can be while still
2450  * guaranteeing ctime changes.  For most filesystems (which have
2451  * timestamps with nanosecond fields) that is limited by the resolution
2452  * of the time returned from current_time() (which I'm assuming to be
2453  * 1/HZ).
2454  */
2455 static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
2456 {
2457 	struct timespec64 ts;
2458 	u32 ns;
2459 
2460 	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
2461 	ts = ns_to_timespec64(ns);
2462 
2463 	p = xdr_encode_hyper(p, ts.tv_sec);
2464 	*p++ = cpu_to_be32(ts.tv_nsec);
2465 
2466 	return p;
2467 }
2468 
2469 static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
2470 {
2471 	*p++ = cpu_to_be32(c->atomic);
2472 	p = xdr_encode_hyper(p, c->before_change);
2473 	p = xdr_encode_hyper(p, c->after_change);
2474 	return p;
2475 }
2476 
2477 /* Encode as an array of strings the string given with components
2478  * separated @sep, escaped with esc_enter and esc_exit.
2479  */
2480 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2481 					  char *components, char esc_enter,
2482 					  char esc_exit)
2483 {
2484 	__be32 *p;
2485 	__be32 pathlen;
2486 	int pathlen_offset;
2487 	int strlen, count=0;
2488 	char *str, *end, *next;
2489 
2490 	dprintk("nfsd4_encode_components(%s)\n", components);
2491 
2492 	pathlen_offset = xdr->buf->len;
2493 	p = xdr_reserve_space(xdr, 4);
2494 	if (!p)
2495 		return nfserr_resource;
2496 	p++; /* We will fill this in with @count later */
2497 
2498 	end = str = components;
2499 	while (*end) {
2500 		bool found_esc = false;
2501 
2502 		/* try to parse as esc_start, ..., esc_end, sep */
2503 		if (*str == esc_enter) {
2504 			for (; *end && (*end != esc_exit); end++)
2505 				/* find esc_exit or end of string */;
2506 			next = end + 1;
2507 			if (*end && (!*next || *next == sep)) {
2508 				str++;
2509 				found_esc = true;
2510 			}
2511 		}
2512 
2513 		if (!found_esc)
2514 			for (; *end && (*end != sep); end++)
2515 				/* find sep or end of string */;
2516 
2517 		strlen = end - str;
2518 		if (strlen) {
2519 			p = xdr_reserve_space(xdr, strlen + 4);
2520 			if (!p)
2521 				return nfserr_resource;
2522 			p = xdr_encode_opaque(p, str, strlen);
2523 			count++;
2524 		}
2525 		else
2526 			end++;
2527 		if (found_esc)
2528 			end = next;
2529 
2530 		str = end;
2531 	}
2532 	pathlen = htonl(count);
2533 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2534 	return 0;
2535 }
2536 
2537 /* Encode as an array of strings the string given with components
2538  * separated @sep.
2539  */
2540 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2541 				      char *components)
2542 {
2543 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2544 }
2545 
2546 /*
2547  * encode a location element of a fs_locations structure
2548  */
2549 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2550 					struct nfsd4_fs_location *location)
2551 {
2552 	__be32 status;
2553 
2554 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2555 						'[', ']');
2556 	if (status)
2557 		return status;
2558 	status = nfsd4_encode_components(xdr, '/', location->path);
2559 	if (status)
2560 		return status;
2561 	return 0;
2562 }
2563 
2564 /*
2565  * Encode a path in RFC3530 'pathname4' format
2566  */
2567 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2568 				const struct path *root,
2569 				const struct path *path)
2570 {
2571 	struct path cur = *path;
2572 	__be32 *p;
2573 	struct dentry **components = NULL;
2574 	unsigned int ncomponents = 0;
2575 	__be32 err = nfserr_jukebox;
2576 
2577 	dprintk("nfsd4_encode_components(");
2578 
2579 	path_get(&cur);
2580 	/* First walk the path up to the nfsd root, and store the
2581 	 * dentries/path components in an array.
2582 	 */
2583 	for (;;) {
2584 		if (path_equal(&cur, root))
2585 			break;
2586 		if (cur.dentry == cur.mnt->mnt_root) {
2587 			if (follow_up(&cur))
2588 				continue;
2589 			goto out_free;
2590 		}
2591 		if ((ncomponents & 15) == 0) {
2592 			struct dentry **new;
2593 			new = krealloc(components,
2594 					sizeof(*new) * (ncomponents + 16),
2595 					GFP_KERNEL);
2596 			if (!new)
2597 				goto out_free;
2598 			components = new;
2599 		}
2600 		components[ncomponents++] = cur.dentry;
2601 		cur.dentry = dget_parent(cur.dentry);
2602 	}
2603 	err = nfserr_resource;
2604 	p = xdr_reserve_space(xdr, 4);
2605 	if (!p)
2606 		goto out_free;
2607 	*p++ = cpu_to_be32(ncomponents);
2608 
2609 	while (ncomponents) {
2610 		struct dentry *dentry = components[ncomponents - 1];
2611 		unsigned int len;
2612 
2613 		spin_lock(&dentry->d_lock);
2614 		len = dentry->d_name.len;
2615 		p = xdr_reserve_space(xdr, len + 4);
2616 		if (!p) {
2617 			spin_unlock(&dentry->d_lock);
2618 			goto out_free;
2619 		}
2620 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2621 		dprintk("/%pd", dentry);
2622 		spin_unlock(&dentry->d_lock);
2623 		dput(dentry);
2624 		ncomponents--;
2625 	}
2626 
2627 	err = 0;
2628 out_free:
2629 	dprintk(")\n");
2630 	while (ncomponents)
2631 		dput(components[--ncomponents]);
2632 	kfree(components);
2633 	path_put(&cur);
2634 	return err;
2635 }
2636 
2637 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2638 			struct svc_rqst *rqstp, const struct path *path)
2639 {
2640 	struct svc_export *exp_ps;
2641 	__be32 res;
2642 
2643 	exp_ps = rqst_find_fsidzero_export(rqstp);
2644 	if (IS_ERR(exp_ps))
2645 		return nfserrno(PTR_ERR(exp_ps));
2646 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2647 	exp_put(exp_ps);
2648 	return res;
2649 }
2650 
2651 /*
2652  *  encode a fs_locations structure
2653  */
2654 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2655 			struct svc_rqst *rqstp, struct svc_export *exp)
2656 {
2657 	__be32 status;
2658 	int i;
2659 	__be32 *p;
2660 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2661 
2662 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2663 	if (status)
2664 		return status;
2665 	p = xdr_reserve_space(xdr, 4);
2666 	if (!p)
2667 		return nfserr_resource;
2668 	*p++ = cpu_to_be32(fslocs->locations_count);
2669 	for (i=0; i<fslocs->locations_count; i++) {
2670 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2671 		if (status)
2672 			return status;
2673 	}
2674 	return 0;
2675 }
2676 
2677 static u32 nfs4_file_type(umode_t mode)
2678 {
2679 	switch (mode & S_IFMT) {
2680 	case S_IFIFO:	return NF4FIFO;
2681 	case S_IFCHR:	return NF4CHR;
2682 	case S_IFDIR:	return NF4DIR;
2683 	case S_IFBLK:	return NF4BLK;
2684 	case S_IFLNK:	return NF4LNK;
2685 	case S_IFREG:	return NF4REG;
2686 	case S_IFSOCK:	return NF4SOCK;
2687 	default:	return NF4BAD;
2688 	}
2689 }
2690 
2691 static inline __be32
2692 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2693 		     struct nfs4_ace *ace)
2694 {
2695 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2696 		return nfs4_acl_write_who(xdr, ace->whotype);
2697 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2698 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2699 	else
2700 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2701 }
2702 
2703 static inline __be32
2704 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2705 {
2706 	__be32		*p;
2707 	unsigned long	i = hweight_long(layout_types);
2708 
2709 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2710 	if (!p)
2711 		return nfserr_resource;
2712 
2713 	*p++ = cpu_to_be32(i);
2714 
2715 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2716 		if (layout_types & (1 << i))
2717 			*p++ = cpu_to_be32(i);
2718 
2719 	return 0;
2720 }
2721 
2722 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2723 			      FATTR4_WORD0_RDATTR_ERROR)
2724 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2725 #define WORD2_ABSENT_FS_ATTRS 0
2726 
2727 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2728 static inline __be32
2729 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2730 			    void *context, int len)
2731 {
2732 	__be32 *p;
2733 
2734 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2735 	if (!p)
2736 		return nfserr_resource;
2737 
2738 	/*
2739 	 * For now we use a 0 here to indicate the null translation; in
2740 	 * the future we may place a call to translation code here.
2741 	 */
2742 	*p++ = cpu_to_be32(0); /* lfs */
2743 	*p++ = cpu_to_be32(0); /* pi */
2744 	p = xdr_encode_opaque(p, context, len);
2745 	return 0;
2746 }
2747 #else
2748 static inline __be32
2749 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2750 			    void *context, int len)
2751 { return 0; }
2752 #endif
2753 
2754 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2755 {
2756 	/* As per referral draft:  */
2757 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2758 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2759 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2760 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2761 			*rdattr_err = NFSERR_MOVED;
2762 		else
2763 			return nfserr_moved;
2764 	}
2765 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2766 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2767 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2768 	return 0;
2769 }
2770 
2771 
2772 static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
2773 {
2774 	struct path path = exp->ex_path;
2775 	int err;
2776 
2777 	path_get(&path);
2778 	while (follow_up(&path)) {
2779 		if (path.dentry != path.mnt->mnt_root)
2780 			break;
2781 	}
2782 	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2783 	path_put(&path);
2784 	return err;
2785 }
2786 
2787 static __be32
2788 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2789 {
2790 	__be32 *p;
2791 
2792 	if (bmval2) {
2793 		p = xdr_reserve_space(xdr, 16);
2794 		if (!p)
2795 			goto out_resource;
2796 		*p++ = cpu_to_be32(3);
2797 		*p++ = cpu_to_be32(bmval0);
2798 		*p++ = cpu_to_be32(bmval1);
2799 		*p++ = cpu_to_be32(bmval2);
2800 	} else if (bmval1) {
2801 		p = xdr_reserve_space(xdr, 12);
2802 		if (!p)
2803 			goto out_resource;
2804 		*p++ = cpu_to_be32(2);
2805 		*p++ = cpu_to_be32(bmval0);
2806 		*p++ = cpu_to_be32(bmval1);
2807 	} else {
2808 		p = xdr_reserve_space(xdr, 8);
2809 		if (!p)
2810 			goto out_resource;
2811 		*p++ = cpu_to_be32(1);
2812 		*p++ = cpu_to_be32(bmval0);
2813 	}
2814 
2815 	return 0;
2816 out_resource:
2817 	return nfserr_resource;
2818 }
2819 
2820 /*
2821  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2822  * ourselves.
2823  */
2824 static __be32
2825 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2826 		struct svc_export *exp,
2827 		struct dentry *dentry, u32 *bmval,
2828 		struct svc_rqst *rqstp, int ignore_crossmnt)
2829 {
2830 	u32 bmval0 = bmval[0];
2831 	u32 bmval1 = bmval[1];
2832 	u32 bmval2 = bmval[2];
2833 	struct kstat stat;
2834 	struct svc_fh *tempfh = NULL;
2835 	struct kstatfs statfs;
2836 	__be32 *p;
2837 	int starting_len = xdr->buf->len;
2838 	int attrlen_offset;
2839 	__be32 attrlen;
2840 	u32 dummy;
2841 	u64 dummy64;
2842 	u32 rdattr_err = 0;
2843 	__be32 status;
2844 	int err;
2845 	struct nfs4_acl *acl = NULL;
2846 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2847 	void *context = NULL;
2848 	int contextlen;
2849 #endif
2850 	bool contextsupport = false;
2851 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2852 	u32 minorversion = resp->cstate.minorversion;
2853 	struct path path = {
2854 		.mnt	= exp->ex_path.mnt,
2855 		.dentry	= dentry,
2856 	};
2857 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2858 
2859 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2860 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2861 
2862 	if (exp->ex_fslocs.migrated) {
2863 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2864 		if (status)
2865 			goto out;
2866 	}
2867 
2868 	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2869 	if (err)
2870 		goto out_nfserr;
2871 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
2872 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
2873 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2874 		       FATTR4_WORD1_SPACE_TOTAL))) {
2875 		err = vfs_statfs(&path, &statfs);
2876 		if (err)
2877 			goto out_nfserr;
2878 	}
2879 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2880 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
2881 		status = nfserr_jukebox;
2882 		if (!tempfh)
2883 			goto out;
2884 		fh_init(tempfh, NFS4_FHSIZE);
2885 		status = fh_compose(tempfh, exp, dentry, NULL);
2886 		if (status)
2887 			goto out;
2888 		fhp = tempfh;
2889 	}
2890 	if (bmval0 & FATTR4_WORD0_ACL) {
2891 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2892 		if (err == -EOPNOTSUPP)
2893 			bmval0 &= ~FATTR4_WORD0_ACL;
2894 		else if (err == -EINVAL) {
2895 			status = nfserr_attrnotsupp;
2896 			goto out;
2897 		} else if (err != 0)
2898 			goto out_nfserr;
2899 	}
2900 
2901 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2902 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
2903 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2904 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
2905 			err = security_inode_getsecctx(d_inode(dentry),
2906 						&context, &contextlen);
2907 		else
2908 			err = -EOPNOTSUPP;
2909 		contextsupport = (err == 0);
2910 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2911 			if (err == -EOPNOTSUPP)
2912 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
2913 			else if (err)
2914 				goto out_nfserr;
2915 		}
2916 	}
2917 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2918 
2919 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
2920 	if (status)
2921 		goto out;
2922 
2923 	attrlen_offset = xdr->buf->len;
2924 	p = xdr_reserve_space(xdr, 4);
2925 	if (!p)
2926 		goto out_resource;
2927 	p++;                /* to be backfilled later */
2928 
2929 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2930 		u32 supp[3];
2931 
2932 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2933 
2934 		if (!IS_POSIXACL(dentry->d_inode))
2935 			supp[0] &= ~FATTR4_WORD0_ACL;
2936 		if (!contextsupport)
2937 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2938 		if (!supp[2]) {
2939 			p = xdr_reserve_space(xdr, 12);
2940 			if (!p)
2941 				goto out_resource;
2942 			*p++ = cpu_to_be32(2);
2943 			*p++ = cpu_to_be32(supp[0]);
2944 			*p++ = cpu_to_be32(supp[1]);
2945 		} else {
2946 			p = xdr_reserve_space(xdr, 16);
2947 			if (!p)
2948 				goto out_resource;
2949 			*p++ = cpu_to_be32(3);
2950 			*p++ = cpu_to_be32(supp[0]);
2951 			*p++ = cpu_to_be32(supp[1]);
2952 			*p++ = cpu_to_be32(supp[2]);
2953 		}
2954 	}
2955 	if (bmval0 & FATTR4_WORD0_TYPE) {
2956 		p = xdr_reserve_space(xdr, 4);
2957 		if (!p)
2958 			goto out_resource;
2959 		dummy = nfs4_file_type(stat.mode);
2960 		if (dummy == NF4BAD) {
2961 			status = nfserr_serverfault;
2962 			goto out;
2963 		}
2964 		*p++ = cpu_to_be32(dummy);
2965 	}
2966 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2967 		p = xdr_reserve_space(xdr, 4);
2968 		if (!p)
2969 			goto out_resource;
2970 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2971 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
2972 		else
2973 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
2974 						NFS4_FH_VOL_RENAME);
2975 	}
2976 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2977 		p = xdr_reserve_space(xdr, 8);
2978 		if (!p)
2979 			goto out_resource;
2980 		p = encode_change(p, &stat, d_inode(dentry), exp);
2981 	}
2982 	if (bmval0 & FATTR4_WORD0_SIZE) {
2983 		p = xdr_reserve_space(xdr, 8);
2984 		if (!p)
2985 			goto out_resource;
2986 		p = xdr_encode_hyper(p, stat.size);
2987 	}
2988 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2989 		p = xdr_reserve_space(xdr, 4);
2990 		if (!p)
2991 			goto out_resource;
2992 		*p++ = cpu_to_be32(1);
2993 	}
2994 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
2995 		p = xdr_reserve_space(xdr, 4);
2996 		if (!p)
2997 			goto out_resource;
2998 		*p++ = cpu_to_be32(1);
2999 	}
3000 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
3001 		p = xdr_reserve_space(xdr, 4);
3002 		if (!p)
3003 			goto out_resource;
3004 		*p++ = cpu_to_be32(0);
3005 	}
3006 	if (bmval0 & FATTR4_WORD0_FSID) {
3007 		p = xdr_reserve_space(xdr, 16);
3008 		if (!p)
3009 			goto out_resource;
3010 		if (exp->ex_fslocs.migrated) {
3011 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
3012 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
3013 		} else switch(fsid_source(fhp)) {
3014 		case FSIDSOURCE_FSID:
3015 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
3016 			p = xdr_encode_hyper(p, (u64)0);
3017 			break;
3018 		case FSIDSOURCE_DEV:
3019 			*p++ = cpu_to_be32(0);
3020 			*p++ = cpu_to_be32(MAJOR(stat.dev));
3021 			*p++ = cpu_to_be32(0);
3022 			*p++ = cpu_to_be32(MINOR(stat.dev));
3023 			break;
3024 		case FSIDSOURCE_UUID:
3025 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
3026 								EX_UUID_LEN);
3027 			break;
3028 		}
3029 	}
3030 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
3031 		p = xdr_reserve_space(xdr, 4);
3032 		if (!p)
3033 			goto out_resource;
3034 		*p++ = cpu_to_be32(0);
3035 	}
3036 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
3037 		p = xdr_reserve_space(xdr, 4);
3038 		if (!p)
3039 			goto out_resource;
3040 		*p++ = cpu_to_be32(nn->nfsd4_lease);
3041 	}
3042 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
3043 		p = xdr_reserve_space(xdr, 4);
3044 		if (!p)
3045 			goto out_resource;
3046 		*p++ = cpu_to_be32(rdattr_err);
3047 	}
3048 	if (bmval0 & FATTR4_WORD0_ACL) {
3049 		struct nfs4_ace *ace;
3050 
3051 		if (acl == NULL) {
3052 			p = xdr_reserve_space(xdr, 4);
3053 			if (!p)
3054 				goto out_resource;
3055 
3056 			*p++ = cpu_to_be32(0);
3057 			goto out_acl;
3058 		}
3059 		p = xdr_reserve_space(xdr, 4);
3060 		if (!p)
3061 			goto out_resource;
3062 		*p++ = cpu_to_be32(acl->naces);
3063 
3064 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3065 			p = xdr_reserve_space(xdr, 4*3);
3066 			if (!p)
3067 				goto out_resource;
3068 			*p++ = cpu_to_be32(ace->type);
3069 			*p++ = cpu_to_be32(ace->flag);
3070 			*p++ = cpu_to_be32(ace->access_mask &
3071 							NFS4_ACE_MASK_ALL);
3072 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
3073 			if (status)
3074 				goto out;
3075 		}
3076 	}
3077 out_acl:
3078 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
3079 		p = xdr_reserve_space(xdr, 4);
3080 		if (!p)
3081 			goto out_resource;
3082 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
3083 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
3084 	}
3085 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
3086 		p = xdr_reserve_space(xdr, 4);
3087 		if (!p)
3088 			goto out_resource;
3089 		*p++ = cpu_to_be32(1);
3090 	}
3091 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
3092 		p = xdr_reserve_space(xdr, 4);
3093 		if (!p)
3094 			goto out_resource;
3095 		*p++ = cpu_to_be32(0);
3096 	}
3097 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
3098 		p = xdr_reserve_space(xdr, 4);
3099 		if (!p)
3100 			goto out_resource;
3101 		*p++ = cpu_to_be32(1);
3102 	}
3103 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
3104 		p = xdr_reserve_space(xdr, 4);
3105 		if (!p)
3106 			goto out_resource;
3107 		*p++ = cpu_to_be32(1);
3108 	}
3109 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
3110 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
3111 		if (!p)
3112 			goto out_resource;
3113 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw,
3114 					fhp->fh_handle.fh_size);
3115 	}
3116 	if (bmval0 & FATTR4_WORD0_FILEID) {
3117 		p = xdr_reserve_space(xdr, 8);
3118 		if (!p)
3119 			goto out_resource;
3120 		p = xdr_encode_hyper(p, stat.ino);
3121 	}
3122 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
3123 		p = xdr_reserve_space(xdr, 8);
3124 		if (!p)
3125 			goto out_resource;
3126 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3127 	}
3128 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
3129 		p = xdr_reserve_space(xdr, 8);
3130 		if (!p)
3131 			goto out_resource;
3132 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3133 	}
3134 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
3135 		p = xdr_reserve_space(xdr, 8);
3136 		if (!p)
3137 			goto out_resource;
3138 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
3139 	}
3140 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
3141 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
3142 		if (status)
3143 			goto out;
3144 	}
3145 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
3146 		p = xdr_reserve_space(xdr, 4);
3147 		if (!p)
3148 			goto out_resource;
3149 		*p++ = cpu_to_be32(1);
3150 	}
3151 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
3152 		p = xdr_reserve_space(xdr, 8);
3153 		if (!p)
3154 			goto out_resource;
3155 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
3156 	}
3157 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
3158 		p = xdr_reserve_space(xdr, 4);
3159 		if (!p)
3160 			goto out_resource;
3161 		*p++ = cpu_to_be32(255);
3162 	}
3163 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
3164 		p = xdr_reserve_space(xdr, 4);
3165 		if (!p)
3166 			goto out_resource;
3167 		*p++ = cpu_to_be32(statfs.f_namelen);
3168 	}
3169 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
3170 		p = xdr_reserve_space(xdr, 8);
3171 		if (!p)
3172 			goto out_resource;
3173 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3174 	}
3175 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
3176 		p = xdr_reserve_space(xdr, 8);
3177 		if (!p)
3178 			goto out_resource;
3179 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3180 	}
3181 	if (bmval1 & FATTR4_WORD1_MODE) {
3182 		p = xdr_reserve_space(xdr, 4);
3183 		if (!p)
3184 			goto out_resource;
3185 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
3186 	}
3187 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
3188 		p = xdr_reserve_space(xdr, 4);
3189 		if (!p)
3190 			goto out_resource;
3191 		*p++ = cpu_to_be32(1);
3192 	}
3193 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
3194 		p = xdr_reserve_space(xdr, 4);
3195 		if (!p)
3196 			goto out_resource;
3197 		*p++ = cpu_to_be32(stat.nlink);
3198 	}
3199 	if (bmval1 & FATTR4_WORD1_OWNER) {
3200 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
3201 		if (status)
3202 			goto out;
3203 	}
3204 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
3205 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
3206 		if (status)
3207 			goto out;
3208 	}
3209 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
3210 		p = xdr_reserve_space(xdr, 8);
3211 		if (!p)
3212 			goto out_resource;
3213 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
3214 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
3215 	}
3216 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
3217 		p = xdr_reserve_space(xdr, 8);
3218 		if (!p)
3219 			goto out_resource;
3220 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
3221 		p = xdr_encode_hyper(p, dummy64);
3222 	}
3223 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
3224 		p = xdr_reserve_space(xdr, 8);
3225 		if (!p)
3226 			goto out_resource;
3227 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
3228 		p = xdr_encode_hyper(p, dummy64);
3229 	}
3230 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
3231 		p = xdr_reserve_space(xdr, 8);
3232 		if (!p)
3233 			goto out_resource;
3234 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
3235 		p = xdr_encode_hyper(p, dummy64);
3236 	}
3237 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
3238 		p = xdr_reserve_space(xdr, 8);
3239 		if (!p)
3240 			goto out_resource;
3241 		dummy64 = (u64)stat.blocks << 9;
3242 		p = xdr_encode_hyper(p, dummy64);
3243 	}
3244 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
3245 		p = xdr_reserve_space(xdr, 12);
3246 		if (!p)
3247 			goto out_resource;
3248 		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
3249 		*p++ = cpu_to_be32(stat.atime.tv_nsec);
3250 	}
3251 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
3252 		p = xdr_reserve_space(xdr, 12);
3253 		if (!p)
3254 			goto out_resource;
3255 		p = encode_time_delta(p, d_inode(dentry));
3256 	}
3257 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
3258 		p = xdr_reserve_space(xdr, 12);
3259 		if (!p)
3260 			goto out_resource;
3261 		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
3262 		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
3263 	}
3264 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
3265 		p = xdr_reserve_space(xdr, 12);
3266 		if (!p)
3267 			goto out_resource;
3268 		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
3269 		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
3270 	}
3271 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
3272 		struct kstat parent_stat;
3273 		u64 ino = stat.ino;
3274 
3275 		p = xdr_reserve_space(xdr, 8);
3276 		if (!p)
3277                 	goto out_resource;
3278 		/*
3279 		 * Get parent's attributes if not ignoring crossmount
3280 		 * and this is the root of a cross-mounted filesystem.
3281 		 */
3282 		if (ignore_crossmnt == 0 &&
3283 		    dentry == exp->ex_path.mnt->mnt_root) {
3284 			err = get_parent_attributes(exp, &parent_stat);
3285 			if (err)
3286 				goto out_nfserr;
3287 			ino = parent_stat.ino;
3288 		}
3289 		p = xdr_encode_hyper(p, ino);
3290 	}
3291 #ifdef CONFIG_NFSD_PNFS
3292 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
3293 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3294 		if (status)
3295 			goto out;
3296 	}
3297 
3298 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
3299 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3300 		if (status)
3301 			goto out;
3302 	}
3303 
3304 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
3305 		p = xdr_reserve_space(xdr, 4);
3306 		if (!p)
3307 			goto out_resource;
3308 		*p++ = cpu_to_be32(stat.blksize);
3309 	}
3310 #endif /* CONFIG_NFSD_PNFS */
3311 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
3312 		u32 supp[3];
3313 
3314 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
3315 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3316 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3317 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3318 
3319 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
3320 		if (status)
3321 			goto out;
3322 	}
3323 
3324 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3325 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
3326 		status = nfsd4_encode_security_label(xdr, rqstp, context,
3327 								contextlen);
3328 		if (status)
3329 			goto out;
3330 	}
3331 #endif
3332 
3333 	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
3334 		p = xdr_reserve_space(xdr, 4);
3335 		if (!p)
3336 			goto out_resource;
3337 		err = xattr_supported_namespace(d_inode(dentry),
3338 						XATTR_USER_PREFIX);
3339 		*p++ = cpu_to_be32(err == 0);
3340 	}
3341 
3342 	attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
3343 	write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
3344 	status = nfs_ok;
3345 
3346 out:
3347 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3348 	if (context)
3349 		security_release_secctx(context, contextlen);
3350 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3351 	kfree(acl);
3352 	if (tempfh) {
3353 		fh_put(tempfh);
3354 		kfree(tempfh);
3355 	}
3356 	if (status)
3357 		xdr_truncate_encode(xdr, starting_len);
3358 	return status;
3359 out_nfserr:
3360 	status = nfserrno(err);
3361 	goto out;
3362 out_resource:
3363 	status = nfserr_resource;
3364 	goto out;
3365 }
3366 
3367 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3368 				struct xdr_buf *buf, __be32 *p, int bytes)
3369 {
3370 	xdr->scratch.iov_len = 0;
3371 	memset(buf, 0, sizeof(struct xdr_buf));
3372 	buf->head[0].iov_base = p;
3373 	buf->head[0].iov_len = 0;
3374 	buf->len = 0;
3375 	xdr->buf = buf;
3376 	xdr->iov = buf->head;
3377 	xdr->p = p;
3378 	xdr->end = (void *)p + bytes;
3379 	buf->buflen = bytes;
3380 }
3381 
3382 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3383 			struct svc_fh *fhp, struct svc_export *exp,
3384 			struct dentry *dentry, u32 *bmval,
3385 			struct svc_rqst *rqstp, int ignore_crossmnt)
3386 {
3387 	struct xdr_buf dummy;
3388 	struct xdr_stream xdr;
3389 	__be32 ret;
3390 
3391 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3392 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
3393 							ignore_crossmnt);
3394 	*p = xdr.p;
3395 	return ret;
3396 }
3397 
3398 static inline int attributes_need_mount(u32 *bmval)
3399 {
3400 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3401 		return 1;
3402 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3403 		return 1;
3404 	return 0;
3405 }
3406 
3407 static __be32
3408 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
3409 			const char *name, int namlen)
3410 {
3411 	struct svc_export *exp = cd->rd_fhp->fh_export;
3412 	struct dentry *dentry;
3413 	__be32 nfserr;
3414 	int ignore_crossmnt = 0;
3415 
3416 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3417 	if (IS_ERR(dentry))
3418 		return nfserrno(PTR_ERR(dentry));
3419 
3420 	exp_get(exp);
3421 	/*
3422 	 * In the case of a mountpoint, the client may be asking for
3423 	 * attributes that are only properties of the underlying filesystem
3424 	 * as opposed to the cross-mounted file system. In such a case,
3425 	 * we will not follow the cross mount and will fill the attribtutes
3426 	 * directly from the mountpoint dentry.
3427 	 */
3428 	if (nfsd_mountpoint(dentry, exp)) {
3429 		int err;
3430 
3431 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3432 				&& !attributes_need_mount(cd->rd_bmval)) {
3433 			ignore_crossmnt = 1;
3434 			goto out_encode;
3435 		}
3436 		/*
3437 		 * Why the heck aren't we just using nfsd_lookup??
3438 		 * Different "."/".." handling?  Something else?
3439 		 * At least, add a comment here to explain....
3440 		 */
3441 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3442 		if (err) {
3443 			nfserr = nfserrno(err);
3444 			goto out_put;
3445 		}
3446 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3447 		if (nfserr)
3448 			goto out_put;
3449 
3450 	}
3451 out_encode:
3452 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
3453 					cd->rd_rqstp, ignore_crossmnt);
3454 out_put:
3455 	dput(dentry);
3456 	exp_put(exp);
3457 	return nfserr;
3458 }
3459 
3460 static __be32 *
3461 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3462 {
3463 	__be32 *p;
3464 
3465 	p = xdr_reserve_space(xdr, 20);
3466 	if (!p)
3467 		return NULL;
3468 	*p++ = htonl(2);
3469 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3470 	*p++ = htonl(0);			 /* bmval1 */
3471 
3472 	*p++ = htonl(4);     /* attribute length */
3473 	*p++ = nfserr;       /* no htonl */
3474 	return p;
3475 }
3476 
3477 static int
3478 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3479 		    loff_t offset, u64 ino, unsigned int d_type)
3480 {
3481 	struct readdir_cd *ccd = ccdv;
3482 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3483 	struct xdr_stream *xdr = cd->xdr;
3484 	int start_offset = xdr->buf->len;
3485 	int cookie_offset;
3486 	u32 name_and_cookie;
3487 	int entry_bytes;
3488 	__be32 nfserr = nfserr_toosmall;
3489 	__be64 wire_offset;
3490 	__be32 *p;
3491 
3492 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3493 	if (name && isdotent(name, namlen)) {
3494 		cd->common.err = nfs_ok;
3495 		return 0;
3496 	}
3497 
3498 	if (cd->cookie_offset) {
3499 		wire_offset = cpu_to_be64(offset);
3500 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3501 							&wire_offset, 8);
3502 	}
3503 
3504 	p = xdr_reserve_space(xdr, 4);
3505 	if (!p)
3506 		goto fail;
3507 	*p++ = xdr_one;                             /* mark entry present */
3508 	cookie_offset = xdr->buf->len;
3509 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3510 	if (!p)
3511 		goto fail;
3512 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
3513 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3514 
3515 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3516 	switch (nfserr) {
3517 	case nfs_ok:
3518 		break;
3519 	case nfserr_resource:
3520 		nfserr = nfserr_toosmall;
3521 		goto fail;
3522 	case nfserr_noent:
3523 		xdr_truncate_encode(xdr, start_offset);
3524 		goto skip_entry;
3525 	default:
3526 		/*
3527 		 * If the client requested the RDATTR_ERROR attribute,
3528 		 * we stuff the error code into this attribute
3529 		 * and continue.  If this attribute was not requested,
3530 		 * then in accordance with the spec, we fail the
3531 		 * entire READDIR operation(!)
3532 		 */
3533 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3534 			goto fail;
3535 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3536 		if (p == NULL) {
3537 			nfserr = nfserr_toosmall;
3538 			goto fail;
3539 		}
3540 	}
3541 	nfserr = nfserr_toosmall;
3542 	entry_bytes = xdr->buf->len - start_offset;
3543 	if (entry_bytes > cd->rd_maxcount)
3544 		goto fail;
3545 	cd->rd_maxcount -= entry_bytes;
3546 	/*
3547 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3548 	 * notes that it could be zero. If it is zero, then the server
3549 	 * should enforce only the rd_maxcount value.
3550 	 */
3551 	if (cd->rd_dircount) {
3552 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3553 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3554 			goto fail;
3555 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3556 		if (!cd->rd_dircount)
3557 			cd->rd_maxcount = 0;
3558 	}
3559 
3560 	cd->cookie_offset = cookie_offset;
3561 skip_entry:
3562 	cd->common.err = nfs_ok;
3563 	return 0;
3564 fail:
3565 	xdr_truncate_encode(xdr, start_offset);
3566 	cd->common.err = nfserr;
3567 	return -EINVAL;
3568 }
3569 
3570 static __be32
3571 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3572 {
3573 	__be32 *p;
3574 
3575 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3576 	if (!p)
3577 		return nfserr_resource;
3578 	*p++ = cpu_to_be32(sid->si_generation);
3579 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3580 					sizeof(stateid_opaque_t));
3581 	return 0;
3582 }
3583 
3584 static __be32
3585 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
3586 {
3587 	struct xdr_stream *xdr = resp->xdr;
3588 	__be32 *p;
3589 
3590 	p = xdr_reserve_space(xdr, 8);
3591 	if (!p)
3592 		return nfserr_resource;
3593 	*p++ = cpu_to_be32(access->ac_supported);
3594 	*p++ = cpu_to_be32(access->ac_resp_access);
3595 	return 0;
3596 }
3597 
3598 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
3599 {
3600 	struct xdr_stream *xdr = resp->xdr;
3601 	__be32 *p;
3602 
3603 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3604 	if (!p)
3605 		return nfserr_resource;
3606 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3607 					NFS4_MAX_SESSIONID_LEN);
3608 	*p++ = cpu_to_be32(bcts->dir);
3609 	/* Upshifting from TCP to RDMA is not supported */
3610 	*p++ = cpu_to_be32(0);
3611 	return 0;
3612 }
3613 
3614 static __be32
3615 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
3616 {
3617 	struct xdr_stream *xdr = resp->xdr;
3618 
3619 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3620 }
3621 
3622 
3623 static __be32
3624 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
3625 {
3626 	struct xdr_stream *xdr = resp->xdr;
3627 	__be32 *p;
3628 
3629 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3630 	if (!p)
3631 		return nfserr_resource;
3632 	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
3633 						NFS4_VERIFIER_SIZE);
3634 	return 0;
3635 }
3636 
3637 static __be32
3638 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
3639 {
3640 	struct xdr_stream *xdr = resp->xdr;
3641 	__be32 *p;
3642 
3643 	p = xdr_reserve_space(xdr, 20);
3644 	if (!p)
3645 		return nfserr_resource;
3646 	encode_cinfo(p, &create->cr_cinfo);
3647 	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3648 			create->cr_bmval[1], create->cr_bmval[2]);
3649 }
3650 
3651 static __be32
3652 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
3653 {
3654 	struct svc_fh *fhp = getattr->ga_fhp;
3655 	struct xdr_stream *xdr = resp->xdr;
3656 
3657 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3658 				    getattr->ga_bmval, resp->rqstp, 0);
3659 }
3660 
3661 static __be32
3662 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
3663 {
3664 	struct xdr_stream *xdr = resp->xdr;
3665 	struct svc_fh *fhp = *fhpp;
3666 	unsigned int len;
3667 	__be32 *p;
3668 
3669 	len = fhp->fh_handle.fh_size;
3670 	p = xdr_reserve_space(xdr, len + 4);
3671 	if (!p)
3672 		return nfserr_resource;
3673 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw, len);
3674 	return 0;
3675 }
3676 
3677 /*
3678 * Including all fields other than the name, a LOCK4denied structure requires
3679 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3680 */
3681 static __be32
3682 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3683 {
3684 	struct xdr_netobj *conf = &ld->ld_owner;
3685 	__be32 *p;
3686 
3687 again:
3688 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3689 	if (!p) {
3690 		/*
3691 		 * Don't fail to return the result just because we can't
3692 		 * return the conflicting open:
3693 		 */
3694 		if (conf->len) {
3695 			kfree(conf->data);
3696 			conf->len = 0;
3697 			conf->data = NULL;
3698 			goto again;
3699 		}
3700 		return nfserr_resource;
3701 	}
3702 	p = xdr_encode_hyper(p, ld->ld_start);
3703 	p = xdr_encode_hyper(p, ld->ld_length);
3704 	*p++ = cpu_to_be32(ld->ld_type);
3705 	if (conf->len) {
3706 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3707 		p = xdr_encode_opaque(p, conf->data, conf->len);
3708 		kfree(conf->data);
3709 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3710 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3711 		*p++ = cpu_to_be32(0); /* length of owner name */
3712 	}
3713 	return nfserr_denied;
3714 }
3715 
3716 static __be32
3717 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
3718 {
3719 	struct xdr_stream *xdr = resp->xdr;
3720 
3721 	if (!nfserr)
3722 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3723 	else if (nfserr == nfserr_denied)
3724 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3725 
3726 	return nfserr;
3727 }
3728 
3729 static __be32
3730 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
3731 {
3732 	struct xdr_stream *xdr = resp->xdr;
3733 
3734 	if (nfserr == nfserr_denied)
3735 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3736 	return nfserr;
3737 }
3738 
3739 static __be32
3740 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
3741 {
3742 	struct xdr_stream *xdr = resp->xdr;
3743 
3744 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3745 }
3746 
3747 
3748 static __be32
3749 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
3750 {
3751 	struct xdr_stream *xdr = resp->xdr;
3752 	__be32 *p;
3753 
3754 	p = xdr_reserve_space(xdr, 20);
3755 	if (!p)
3756 		return nfserr_resource;
3757 	p = encode_cinfo(p, &link->li_cinfo);
3758 	return 0;
3759 }
3760 
3761 
3762 static __be32
3763 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
3764 {
3765 	struct xdr_stream *xdr = resp->xdr;
3766 	__be32 *p;
3767 
3768 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3769 	if (nfserr)
3770 		return nfserr;
3771 	p = xdr_reserve_space(xdr, 24);
3772 	if (!p)
3773 		return nfserr_resource;
3774 	p = encode_cinfo(p, &open->op_cinfo);
3775 	*p++ = cpu_to_be32(open->op_rflags);
3776 
3777 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3778 					open->op_bmval[2]);
3779 	if (nfserr)
3780 		return nfserr;
3781 
3782 	p = xdr_reserve_space(xdr, 4);
3783 	if (!p)
3784 		return nfserr_resource;
3785 
3786 	*p++ = cpu_to_be32(open->op_delegate_type);
3787 	switch (open->op_delegate_type) {
3788 	case NFS4_OPEN_DELEGATE_NONE:
3789 		break;
3790 	case NFS4_OPEN_DELEGATE_READ:
3791 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3792 		if (nfserr)
3793 			return nfserr;
3794 		p = xdr_reserve_space(xdr, 20);
3795 		if (!p)
3796 			return nfserr_resource;
3797 		*p++ = cpu_to_be32(open->op_recall);
3798 
3799 		/*
3800 		 * TODO: ACE's in delegations
3801 		 */
3802 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3803 		*p++ = cpu_to_be32(0);
3804 		*p++ = cpu_to_be32(0);
3805 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3806 		break;
3807 	case NFS4_OPEN_DELEGATE_WRITE:
3808 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3809 		if (nfserr)
3810 			return nfserr;
3811 		p = xdr_reserve_space(xdr, 32);
3812 		if (!p)
3813 			return nfserr_resource;
3814 		*p++ = cpu_to_be32(0);
3815 
3816 		/*
3817 		 * TODO: space_limit's in delegations
3818 		 */
3819 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3820 		*p++ = cpu_to_be32(~(u32)0);
3821 		*p++ = cpu_to_be32(~(u32)0);
3822 
3823 		/*
3824 		 * TODO: ACE's in delegations
3825 		 */
3826 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3827 		*p++ = cpu_to_be32(0);
3828 		*p++ = cpu_to_be32(0);
3829 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3830 		break;
3831 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
3832 		switch (open->op_why_no_deleg) {
3833 		case WND4_CONTENTION:
3834 		case WND4_RESOURCE:
3835 			p = xdr_reserve_space(xdr, 8);
3836 			if (!p)
3837 				return nfserr_resource;
3838 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3839 			/* deleg signaling not supported yet: */
3840 			*p++ = cpu_to_be32(0);
3841 			break;
3842 		default:
3843 			p = xdr_reserve_space(xdr, 4);
3844 			if (!p)
3845 				return nfserr_resource;
3846 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3847 		}
3848 		break;
3849 	default:
3850 		BUG();
3851 	}
3852 	/* XXX save filehandle here */
3853 	return 0;
3854 }
3855 
3856 static __be32
3857 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
3858 {
3859 	struct xdr_stream *xdr = resp->xdr;
3860 
3861 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
3862 }
3863 
3864 static __be32
3865 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
3866 {
3867 	struct xdr_stream *xdr = resp->xdr;
3868 
3869 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
3870 }
3871 
3872 static __be32 nfsd4_encode_splice_read(
3873 				struct nfsd4_compoundres *resp,
3874 				struct nfsd4_read *read,
3875 				struct file *file, unsigned long maxcount)
3876 {
3877 	struct xdr_stream *xdr = resp->xdr;
3878 	struct xdr_buf *buf = xdr->buf;
3879 	int status, space_left;
3880 	u32 eof;
3881 	__be32 nfserr;
3882 	__be32 *p = xdr->p - 2;
3883 
3884 	/* Make sure there will be room for padding if needed */
3885 	if (xdr->end - xdr->p < 1)
3886 		return nfserr_resource;
3887 
3888 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
3889 				  file, read->rd_offset, &maxcount, &eof);
3890 	read->rd_length = maxcount;
3891 	if (nfserr)
3892 		goto out_err;
3893 	status = svc_encode_result_payload(read->rd_rqstp,
3894 					   buf->head[0].iov_len, maxcount);
3895 	if (status) {
3896 		nfserr = nfserrno(status);
3897 		goto out_err;
3898 	}
3899 
3900 	*(p++) = htonl(eof);
3901 	*(p++) = htonl(maxcount);
3902 
3903 	buf->page_len = maxcount;
3904 	buf->len += maxcount;
3905 	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
3906 							/ PAGE_SIZE;
3907 
3908 	/* Use rest of head for padding and remaining ops: */
3909 	buf->tail[0].iov_base = xdr->p;
3910 	buf->tail[0].iov_len = 0;
3911 	xdr->iov = buf->tail;
3912 	if (maxcount&3) {
3913 		int pad = 4 - (maxcount&3);
3914 
3915 		*(xdr->p++) = 0;
3916 
3917 		buf->tail[0].iov_base += maxcount&3;
3918 		buf->tail[0].iov_len = pad;
3919 		buf->len += pad;
3920 	}
3921 
3922 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
3923 				buf->buflen - buf->len);
3924 	buf->buflen = buf->len + space_left;
3925 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
3926 
3927 	return 0;
3928 
3929 out_err:
3930 	/*
3931 	 * nfsd_splice_actor may have already messed with the
3932 	 * page length; reset it so as not to confuse
3933 	 * xdr_truncate_encode in our caller.
3934 	 */
3935 	buf->page_len = 0;
3936 	return nfserr;
3937 }
3938 
3939 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
3940 				 struct nfsd4_read *read,
3941 				 struct file *file, unsigned long maxcount)
3942 {
3943 	struct xdr_stream *xdr = resp->xdr;
3944 	u32 eof;
3945 	int starting_len = xdr->buf->len - 8;
3946 	__be32 nfserr;
3947 	__be32 tmp;
3948 	int pad;
3949 
3950 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
3951 	if (read->rd_vlen < 0)
3952 		return nfserr_resource;
3953 
3954 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
3955 			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
3956 			    &eof);
3957 	read->rd_length = maxcount;
3958 	if (nfserr)
3959 		return nfserr;
3960 	if (svc_encode_result_payload(resp->rqstp, starting_len + 8, maxcount))
3961 		return nfserr_io;
3962 	xdr_truncate_encode(xdr, starting_len + 8 + xdr_align_size(maxcount));
3963 
3964 	tmp = htonl(eof);
3965 	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
3966 	tmp = htonl(maxcount);
3967 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
3968 
3969 	tmp = xdr_zero;
3970 	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
3971 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
3972 								&tmp, pad);
3973 	return 0;
3974 
3975 }
3976 
3977 static __be32
3978 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
3979 		  struct nfsd4_read *read)
3980 {
3981 	unsigned long maxcount;
3982 	struct xdr_stream *xdr = resp->xdr;
3983 	struct file *file;
3984 	int starting_len = xdr->buf->len;
3985 	__be32 *p;
3986 
3987 	if (nfserr)
3988 		return nfserr;
3989 	file = read->rd_nf->nf_file;
3990 
3991 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
3992 	if (!p) {
3993 		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
3994 		return nfserr_resource;
3995 	}
3996 	if (resp->xdr->buf->page_len &&
3997 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
3998 		WARN_ON_ONCE(1);
3999 		return nfserr_resource;
4000 	}
4001 	xdr_commit_encode(xdr);
4002 
4003 	maxcount = svc_max_payload(resp->rqstp);
4004 	maxcount = min_t(unsigned long, maxcount,
4005 			 (xdr->buf->buflen - xdr->buf->len));
4006 	maxcount = min_t(unsigned long, maxcount, read->rd_length);
4007 
4008 	if (file->f_op->splice_read &&
4009 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
4010 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4011 	else
4012 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4013 
4014 	if (nfserr)
4015 		xdr_truncate_encode(xdr, starting_len);
4016 
4017 	return nfserr;
4018 }
4019 
4020 static __be32
4021 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
4022 {
4023 	int maxcount;
4024 	__be32 wire_count;
4025 	int zero = 0;
4026 	struct xdr_stream *xdr = resp->xdr;
4027 	int length_offset = xdr->buf->len;
4028 	int status;
4029 	__be32 *p;
4030 
4031 	p = xdr_reserve_space(xdr, 4);
4032 	if (!p)
4033 		return nfserr_resource;
4034 	maxcount = PAGE_SIZE;
4035 
4036 	p = xdr_reserve_space(xdr, maxcount);
4037 	if (!p)
4038 		return nfserr_resource;
4039 	/*
4040 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4041 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4042 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4043 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4044 	 */
4045 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4046 						(char *)p, &maxcount);
4047 	if (nfserr == nfserr_isdir)
4048 		nfserr = nfserr_inval;
4049 	if (nfserr)
4050 		goto out_err;
4051 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4052 					   maxcount);
4053 	if (status) {
4054 		nfserr = nfserrno(status);
4055 		goto out_err;
4056 	}
4057 
4058 	wire_count = htonl(maxcount);
4059 	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
4060 	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
4061 	if (maxcount & 3)
4062 		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
4063 						&zero, 4 - (maxcount&3));
4064 	return 0;
4065 
4066 out_err:
4067 	xdr_truncate_encode(xdr, length_offset);
4068 	return nfserr;
4069 }
4070 
4071 static __be32
4072 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
4073 {
4074 	int maxcount;
4075 	int bytes_left;
4076 	loff_t offset;
4077 	__be64 wire_offset;
4078 	struct xdr_stream *xdr = resp->xdr;
4079 	int starting_len = xdr->buf->len;
4080 	__be32 *p;
4081 
4082 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
4083 	if (!p)
4084 		return nfserr_resource;
4085 
4086 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
4087 	*p++ = cpu_to_be32(0);
4088 	*p++ = cpu_to_be32(0);
4089 	xdr->buf->head[0].iov_len = (char *)xdr->p -
4090 				    (char *)xdr->buf->head[0].iov_base;
4091 
4092 	/*
4093 	 * Number of bytes left for directory entries allowing for the
4094 	 * final 8 bytes of the readdir and a following failed op:
4095 	 */
4096 	bytes_left = xdr->buf->buflen - xdr->buf->len
4097 			- COMPOUND_ERR_SLACK_SPACE - 8;
4098 	if (bytes_left < 0) {
4099 		nfserr = nfserr_resource;
4100 		goto err_no_verf;
4101 	}
4102 	maxcount = svc_max_payload(resp->rqstp);
4103 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
4104 	/*
4105 	 * Note the rfc defines rd_maxcount as the size of the
4106 	 * READDIR4resok structure, which includes the verifier above
4107 	 * and the 8 bytes encoded at the end of this function:
4108 	 */
4109 	if (maxcount < 16) {
4110 		nfserr = nfserr_toosmall;
4111 		goto err_no_verf;
4112 	}
4113 	maxcount = min_t(int, maxcount-16, bytes_left);
4114 
4115 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
4116 	if (!readdir->rd_dircount)
4117 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
4118 
4119 	readdir->xdr = xdr;
4120 	readdir->rd_maxcount = maxcount;
4121 	readdir->common.err = 0;
4122 	readdir->cookie_offset = 0;
4123 
4124 	offset = readdir->rd_cookie;
4125 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
4126 			      &offset,
4127 			      &readdir->common, nfsd4_encode_dirent);
4128 	if (nfserr == nfs_ok &&
4129 	    readdir->common.err == nfserr_toosmall &&
4130 	    xdr->buf->len == starting_len + 8) {
4131 		/* nothing encoded; which limit did we hit?: */
4132 		if (maxcount - 16 < bytes_left)
4133 			/* It was the fault of rd_maxcount: */
4134 			nfserr = nfserr_toosmall;
4135 		else
4136 			/* We ran out of buffer space: */
4137 			nfserr = nfserr_resource;
4138 	}
4139 	if (nfserr)
4140 		goto err_no_verf;
4141 
4142 	if (readdir->cookie_offset) {
4143 		wire_offset = cpu_to_be64(offset);
4144 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
4145 							&wire_offset, 8);
4146 	}
4147 
4148 	p = xdr_reserve_space(xdr, 8);
4149 	if (!p) {
4150 		WARN_ON_ONCE(1);
4151 		goto err_no_verf;
4152 	}
4153 	*p++ = 0;	/* no more entries */
4154 	*p++ = htonl(readdir->common.err == nfserr_eof);
4155 
4156 	return 0;
4157 err_no_verf:
4158 	xdr_truncate_encode(xdr, starting_len);
4159 	return nfserr;
4160 }
4161 
4162 static __be32
4163 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
4164 {
4165 	struct xdr_stream *xdr = resp->xdr;
4166 	__be32 *p;
4167 
4168 	p = xdr_reserve_space(xdr, 20);
4169 	if (!p)
4170 		return nfserr_resource;
4171 	p = encode_cinfo(p, &remove->rm_cinfo);
4172 	return 0;
4173 }
4174 
4175 static __be32
4176 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
4177 {
4178 	struct xdr_stream *xdr = resp->xdr;
4179 	__be32 *p;
4180 
4181 	p = xdr_reserve_space(xdr, 40);
4182 	if (!p)
4183 		return nfserr_resource;
4184 	p = encode_cinfo(p, &rename->rn_sinfo);
4185 	p = encode_cinfo(p, &rename->rn_tinfo);
4186 	return 0;
4187 }
4188 
4189 static __be32
4190 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4191 {
4192 	u32 i, nflavs, supported;
4193 	struct exp_flavor_info *flavs;
4194 	struct exp_flavor_info def_flavs[2];
4195 	__be32 *p, *flavorsp;
4196 	static bool report = true;
4197 
4198 	if (exp->ex_nflavors) {
4199 		flavs = exp->ex_flavors;
4200 		nflavs = exp->ex_nflavors;
4201 	} else { /* Handling of some defaults in absence of real secinfo: */
4202 		flavs = def_flavs;
4203 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4204 			nflavs = 2;
4205 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4206 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4207 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4208 			nflavs = 1;
4209 			flavs[0].pseudoflavor
4210 					= svcauth_gss_flavor(exp->ex_client);
4211 		} else {
4212 			nflavs = 1;
4213 			flavs[0].pseudoflavor
4214 					= exp->ex_client->flavour->flavour;
4215 		}
4216 	}
4217 
4218 	supported = 0;
4219 	p = xdr_reserve_space(xdr, 4);
4220 	if (!p)
4221 		return nfserr_resource;
4222 	flavorsp = p++;		/* to be backfilled later */
4223 
4224 	for (i = 0; i < nflavs; i++) {
4225 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4226 		struct rpcsec_gss_info info;
4227 
4228 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4229 			supported++;
4230 			p = xdr_reserve_space(xdr, 4 + 4 +
4231 					      XDR_LEN(info.oid.len) + 4 + 4);
4232 			if (!p)
4233 				return nfserr_resource;
4234 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
4235 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
4236 			*p++ = cpu_to_be32(info.qop);
4237 			*p++ = cpu_to_be32(info.service);
4238 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4239 			supported++;
4240 			p = xdr_reserve_space(xdr, 4);
4241 			if (!p)
4242 				return nfserr_resource;
4243 			*p++ = cpu_to_be32(pf);
4244 		} else {
4245 			if (report)
4246 				pr_warn("NFS: SECINFO: security flavor %u "
4247 					"is not supported\n", pf);
4248 		}
4249 	}
4250 
4251 	if (nflavs != supported)
4252 		report = false;
4253 	*flavorsp = htonl(supported);
4254 	return 0;
4255 }
4256 
4257 static __be32
4258 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4259 		     struct nfsd4_secinfo *secinfo)
4260 {
4261 	struct xdr_stream *xdr = resp->xdr;
4262 
4263 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4264 }
4265 
4266 static __be32
4267 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4268 		     struct nfsd4_secinfo_no_name *secinfo)
4269 {
4270 	struct xdr_stream *xdr = resp->xdr;
4271 
4272 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4273 }
4274 
4275 /*
4276  * The SETATTR encode routine is special -- it always encodes a bitmap,
4277  * regardless of the error status.
4278  */
4279 static __be32
4280 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
4281 {
4282 	struct xdr_stream *xdr = resp->xdr;
4283 	__be32 *p;
4284 
4285 	p = xdr_reserve_space(xdr, 16);
4286 	if (!p)
4287 		return nfserr_resource;
4288 	if (nfserr) {
4289 		*p++ = cpu_to_be32(3);
4290 		*p++ = cpu_to_be32(0);
4291 		*p++ = cpu_to_be32(0);
4292 		*p++ = cpu_to_be32(0);
4293 	}
4294 	else {
4295 		*p++ = cpu_to_be32(3);
4296 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
4297 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
4298 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
4299 	}
4300 	return nfserr;
4301 }
4302 
4303 static __be32
4304 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
4305 {
4306 	struct xdr_stream *xdr = resp->xdr;
4307 	__be32 *p;
4308 
4309 	if (!nfserr) {
4310 		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
4311 		if (!p)
4312 			return nfserr_resource;
4313 		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
4314 		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
4315 						NFS4_VERIFIER_SIZE);
4316 	}
4317 	else if (nfserr == nfserr_clid_inuse) {
4318 		p = xdr_reserve_space(xdr, 8);
4319 		if (!p)
4320 			return nfserr_resource;
4321 		*p++ = cpu_to_be32(0);
4322 		*p++ = cpu_to_be32(0);
4323 	}
4324 	return nfserr;
4325 }
4326 
4327 static __be32
4328 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
4329 {
4330 	struct xdr_stream *xdr = resp->xdr;
4331 	__be32 *p;
4332 
4333 	p = xdr_reserve_space(xdr, 16);
4334 	if (!p)
4335 		return nfserr_resource;
4336 	*p++ = cpu_to_be32(write->wr_bytes_written);
4337 	*p++ = cpu_to_be32(write->wr_how_written);
4338 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4339 						NFS4_VERIFIER_SIZE);
4340 	return 0;
4341 }
4342 
4343 static __be32
4344 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4345 			 struct nfsd4_exchange_id *exid)
4346 {
4347 	struct xdr_stream *xdr = resp->xdr;
4348 	__be32 *p;
4349 	char *major_id;
4350 	char *server_scope;
4351 	int major_id_sz;
4352 	int server_scope_sz;
4353 	uint64_t minor_id = 0;
4354 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4355 
4356 	major_id = nn->nfsd_name;
4357 	major_id_sz = strlen(nn->nfsd_name);
4358 	server_scope = nn->nfsd_name;
4359 	server_scope_sz = strlen(nn->nfsd_name);
4360 
4361 	p = xdr_reserve_space(xdr,
4362 		8 /* eir_clientid */ +
4363 		4 /* eir_sequenceid */ +
4364 		4 /* eir_flags */ +
4365 		4 /* spr_how */);
4366 	if (!p)
4367 		return nfserr_resource;
4368 
4369 	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
4370 	*p++ = cpu_to_be32(exid->seqid);
4371 	*p++ = cpu_to_be32(exid->flags);
4372 
4373 	*p++ = cpu_to_be32(exid->spa_how);
4374 
4375 	switch (exid->spa_how) {
4376 	case SP4_NONE:
4377 		break;
4378 	case SP4_MACH_CRED:
4379 		/* spo_must_enforce bitmap: */
4380 		nfserr = nfsd4_encode_bitmap(xdr,
4381 					exid->spo_must_enforce[0],
4382 					exid->spo_must_enforce[1],
4383 					exid->spo_must_enforce[2]);
4384 		if (nfserr)
4385 			return nfserr;
4386 		/* spo_must_allow bitmap: */
4387 		nfserr = nfsd4_encode_bitmap(xdr,
4388 					exid->spo_must_allow[0],
4389 					exid->spo_must_allow[1],
4390 					exid->spo_must_allow[2]);
4391 		if (nfserr)
4392 			return nfserr;
4393 		break;
4394 	default:
4395 		WARN_ON_ONCE(1);
4396 	}
4397 
4398 	p = xdr_reserve_space(xdr,
4399 		8 /* so_minor_id */ +
4400 		4 /* so_major_id.len */ +
4401 		(XDR_QUADLEN(major_id_sz) * 4) +
4402 		4 /* eir_server_scope.len */ +
4403 		(XDR_QUADLEN(server_scope_sz) * 4) +
4404 		4 /* eir_server_impl_id.count (0) */);
4405 	if (!p)
4406 		return nfserr_resource;
4407 
4408 	/* The server_owner struct */
4409 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
4410 	/* major id */
4411 	p = xdr_encode_opaque(p, major_id, major_id_sz);
4412 
4413 	/* Server scope */
4414 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
4415 
4416 	/* Implementation id */
4417 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
4418 	return 0;
4419 }
4420 
4421 static __be32
4422 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4423 			    struct nfsd4_create_session *sess)
4424 {
4425 	struct xdr_stream *xdr = resp->xdr;
4426 	__be32 *p;
4427 
4428 	p = xdr_reserve_space(xdr, 24);
4429 	if (!p)
4430 		return nfserr_resource;
4431 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
4432 					NFS4_MAX_SESSIONID_LEN);
4433 	*p++ = cpu_to_be32(sess->seqid);
4434 	*p++ = cpu_to_be32(sess->flags);
4435 
4436 	p = xdr_reserve_space(xdr, 28);
4437 	if (!p)
4438 		return nfserr_resource;
4439 	*p++ = cpu_to_be32(0); /* headerpadsz */
4440 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
4441 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
4442 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
4443 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4444 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4445 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4446 
4447 	if (sess->fore_channel.nr_rdma_attrs) {
4448 		p = xdr_reserve_space(xdr, 4);
4449 		if (!p)
4450 			return nfserr_resource;
4451 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4452 	}
4453 
4454 	p = xdr_reserve_space(xdr, 28);
4455 	if (!p)
4456 		return nfserr_resource;
4457 	*p++ = cpu_to_be32(0); /* headerpadsz */
4458 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4459 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4460 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4461 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4462 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4463 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4464 
4465 	if (sess->back_channel.nr_rdma_attrs) {
4466 		p = xdr_reserve_space(xdr, 4);
4467 		if (!p)
4468 			return nfserr_resource;
4469 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4470 	}
4471 	return 0;
4472 }
4473 
4474 static __be32
4475 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4476 		      struct nfsd4_sequence *seq)
4477 {
4478 	struct xdr_stream *xdr = resp->xdr;
4479 	__be32 *p;
4480 
4481 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4482 	if (!p)
4483 		return nfserr_resource;
4484 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4485 					NFS4_MAX_SESSIONID_LEN);
4486 	*p++ = cpu_to_be32(seq->seqid);
4487 	*p++ = cpu_to_be32(seq->slotid);
4488 	/* Note slotid's are numbered from zero: */
4489 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4490 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4491 	*p++ = cpu_to_be32(seq->status_flags);
4492 
4493 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4494 	return 0;
4495 }
4496 
4497 static __be32
4498 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4499 			  struct nfsd4_test_stateid *test_stateid)
4500 {
4501 	struct xdr_stream *xdr = resp->xdr;
4502 	struct nfsd4_test_stateid_id *stateid, *next;
4503 	__be32 *p;
4504 
4505 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4506 	if (!p)
4507 		return nfserr_resource;
4508 	*p++ = htonl(test_stateid->ts_num_ids);
4509 
4510 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4511 		*p++ = stateid->ts_id_status;
4512 	}
4513 
4514 	return 0;
4515 }
4516 
4517 #ifdef CONFIG_NFSD_PNFS
4518 static __be32
4519 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4520 		struct nfsd4_getdeviceinfo *gdev)
4521 {
4522 	struct xdr_stream *xdr = resp->xdr;
4523 	const struct nfsd4_layout_ops *ops;
4524 	u32 starting_len = xdr->buf->len, needed_len;
4525 	__be32 *p;
4526 
4527 	p = xdr_reserve_space(xdr, 4);
4528 	if (!p)
4529 		return nfserr_resource;
4530 
4531 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4532 
4533 	/* If maxcount is 0 then just update notifications */
4534 	if (gdev->gd_maxcount != 0) {
4535 		ops = nfsd4_layout_ops[gdev->gd_layout_type];
4536 		nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4537 		if (nfserr) {
4538 			/*
4539 			 * We don't bother to burden the layout drivers with
4540 			 * enforcing gd_maxcount, just tell the client to
4541 			 * come back with a bigger buffer if it's not enough.
4542 			 */
4543 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
4544 				goto toosmall;
4545 			return nfserr;
4546 		}
4547 	}
4548 
4549 	if (gdev->gd_notify_types) {
4550 		p = xdr_reserve_space(xdr, 4 + 4);
4551 		if (!p)
4552 			return nfserr_resource;
4553 		*p++ = cpu_to_be32(1);			/* bitmap length */
4554 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4555 	} else {
4556 		p = xdr_reserve_space(xdr, 4);
4557 		if (!p)
4558 			return nfserr_resource;
4559 		*p++ = 0;
4560 	}
4561 
4562 	return 0;
4563 toosmall:
4564 	dprintk("%s: maxcount too small\n", __func__);
4565 	needed_len = xdr->buf->len + 4 /* notifications */;
4566 	xdr_truncate_encode(xdr, starting_len);
4567 	p = xdr_reserve_space(xdr, 4);
4568 	if (!p)
4569 		return nfserr_resource;
4570 	*p++ = cpu_to_be32(needed_len);
4571 	return nfserr_toosmall;
4572 }
4573 
4574 static __be32
4575 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4576 		struct nfsd4_layoutget *lgp)
4577 {
4578 	struct xdr_stream *xdr = resp->xdr;
4579 	const struct nfsd4_layout_ops *ops;
4580 	__be32 *p;
4581 
4582 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4583 	if (!p)
4584 		return nfserr_resource;
4585 
4586 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4587 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4588 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4589 				    sizeof(stateid_opaque_t));
4590 
4591 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4592 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4593 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4594 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4595 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4596 
4597 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4598 	return ops->encode_layoutget(xdr, lgp);
4599 }
4600 
4601 static __be32
4602 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4603 			  struct nfsd4_layoutcommit *lcp)
4604 {
4605 	struct xdr_stream *xdr = resp->xdr;
4606 	__be32 *p;
4607 
4608 	p = xdr_reserve_space(xdr, 4);
4609 	if (!p)
4610 		return nfserr_resource;
4611 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4612 	if (lcp->lc_size_chg) {
4613 		p = xdr_reserve_space(xdr, 8);
4614 		if (!p)
4615 			return nfserr_resource;
4616 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4617 	}
4618 
4619 	return 0;
4620 }
4621 
4622 static __be32
4623 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4624 		struct nfsd4_layoutreturn *lrp)
4625 {
4626 	struct xdr_stream *xdr = resp->xdr;
4627 	__be32 *p;
4628 
4629 	p = xdr_reserve_space(xdr, 4);
4630 	if (!p)
4631 		return nfserr_resource;
4632 	*p++ = cpu_to_be32(lrp->lrs_present);
4633 	if (lrp->lrs_present)
4634 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4635 	return 0;
4636 }
4637 #endif /* CONFIG_NFSD_PNFS */
4638 
4639 static __be32
4640 nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
4641 		struct nfsd42_write_res *write, bool sync)
4642 {
4643 	__be32 *p;
4644 	p = xdr_reserve_space(resp->xdr, 4);
4645 	if (!p)
4646 		return nfserr_resource;
4647 
4648 	if (sync)
4649 		*p++ = cpu_to_be32(0);
4650 	else {
4651 		__be32 nfserr;
4652 		*p++ = cpu_to_be32(1);
4653 		nfserr = nfsd4_encode_stateid(resp->xdr, &write->cb_stateid);
4654 		if (nfserr)
4655 			return nfserr;
4656 	}
4657 	p = xdr_reserve_space(resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
4658 	if (!p)
4659 		return nfserr_resource;
4660 
4661 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4662 	*p++ = cpu_to_be32(write->wr_stable_how);
4663 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4664 				    NFS4_VERIFIER_SIZE);
4665 	return nfs_ok;
4666 }
4667 
4668 static __be32
4669 nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
4670 {
4671 	struct xdr_stream *xdr = resp->xdr;
4672 	struct nfs42_netaddr *addr;
4673 	__be32 *p;
4674 
4675 	p = xdr_reserve_space(xdr, 4);
4676 	*p++ = cpu_to_be32(ns->nl4_type);
4677 
4678 	switch (ns->nl4_type) {
4679 	case NL4_NETADDR:
4680 		addr = &ns->u.nl4_addr;
4681 
4682 		/* netid_len, netid, uaddr_len, uaddr (port included
4683 		 * in RPCBIND_MAXUADDRLEN)
4684 		 */
4685 		p = xdr_reserve_space(xdr,
4686 			4 /* netid len */ +
4687 			(XDR_QUADLEN(addr->netid_len) * 4) +
4688 			4 /* uaddr len */ +
4689 			(XDR_QUADLEN(addr->addr_len) * 4));
4690 		if (!p)
4691 			return nfserr_resource;
4692 
4693 		*p++ = cpu_to_be32(addr->netid_len);
4694 		p = xdr_encode_opaque_fixed(p, addr->netid,
4695 					    addr->netid_len);
4696 		*p++ = cpu_to_be32(addr->addr_len);
4697 		p = xdr_encode_opaque_fixed(p, addr->addr,
4698 					addr->addr_len);
4699 		break;
4700 	default:
4701 		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
4702 		return nfserr_inval;
4703 	}
4704 
4705 	return 0;
4706 }
4707 
4708 static __be32
4709 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4710 		  struct nfsd4_copy *copy)
4711 {
4712 	__be32 *p;
4713 
4714 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
4715 					 !!copy->cp_synchronous);
4716 	if (nfserr)
4717 		return nfserr;
4718 
4719 	p = xdr_reserve_space(resp->xdr, 4 + 4);
4720 	*p++ = xdr_one; /* cr_consecutive */
4721 	*p++ = cpu_to_be32(copy->cp_synchronous);
4722 	return 0;
4723 }
4724 
4725 static __be32
4726 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
4727 			    struct nfsd4_offload_status *os)
4728 {
4729 	struct xdr_stream *xdr = resp->xdr;
4730 	__be32 *p;
4731 
4732 	p = xdr_reserve_space(xdr, 8 + 4);
4733 	if (!p)
4734 		return nfserr_resource;
4735 	p = xdr_encode_hyper(p, os->count);
4736 	*p++ = cpu_to_be32(0);
4737 	return nfserr;
4738 }
4739 
4740 static __be32
4741 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
4742 			    struct nfsd4_read *read,
4743 			    unsigned long *maxcount, u32 *eof,
4744 			    loff_t *pos)
4745 {
4746 	struct xdr_stream *xdr = resp->xdr;
4747 	struct file *file = read->rd_nf->nf_file;
4748 	int starting_len = xdr->buf->len;
4749 	loff_t hole_pos;
4750 	__be32 nfserr;
4751 	__be32 *p, tmp;
4752 	__be64 tmp64;
4753 
4754 	hole_pos = pos ? *pos : vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4755 	if (hole_pos > read->rd_offset)
4756 		*maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
4757 	*maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
4758 
4759 	/* Content type, offset, byte count */
4760 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
4761 	if (!p)
4762 		return nfserr_resource;
4763 
4764 	read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
4765 	if (read->rd_vlen < 0)
4766 		return nfserr_resource;
4767 
4768 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
4769 			    resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
4770 	if (nfserr)
4771 		return nfserr;
4772 	xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
4773 
4774 	tmp = htonl(NFS4_CONTENT_DATA);
4775 	write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
4776 	tmp64 = cpu_to_be64(read->rd_offset);
4777 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
4778 	tmp = htonl(*maxcount);
4779 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
4780 
4781 	tmp = xdr_zero;
4782 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
4783 			       xdr_pad_size(*maxcount));
4784 	return nfs_ok;
4785 }
4786 
4787 static __be32
4788 nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
4789 			    struct nfsd4_read *read,
4790 			    unsigned long *maxcount, u32 *eof)
4791 {
4792 	struct file *file = read->rd_nf->nf_file;
4793 	loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
4794 	loff_t f_size = i_size_read(file_inode(file));
4795 	unsigned long count;
4796 	__be32 *p;
4797 
4798 	if (data_pos == -ENXIO)
4799 		data_pos = f_size;
4800 	else if (data_pos <= read->rd_offset || (data_pos < f_size && data_pos % PAGE_SIZE))
4801 		return nfsd4_encode_read_plus_data(resp, read, maxcount, eof, &f_size);
4802 	count = data_pos - read->rd_offset;
4803 
4804 	/* Content type, offset, byte count */
4805 	p = xdr_reserve_space(resp->xdr, 4 + 8 + 8);
4806 	if (!p)
4807 		return nfserr_resource;
4808 
4809 	*p++ = htonl(NFS4_CONTENT_HOLE);
4810 	 p   = xdr_encode_hyper(p, read->rd_offset);
4811 	 p   = xdr_encode_hyper(p, count);
4812 
4813 	*eof = (read->rd_offset + count) >= f_size;
4814 	*maxcount = min_t(unsigned long, count, *maxcount);
4815 	return nfs_ok;
4816 }
4817 
4818 static __be32
4819 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
4820 		       struct nfsd4_read *read)
4821 {
4822 	unsigned long maxcount, count;
4823 	struct xdr_stream *xdr = resp->xdr;
4824 	struct file *file;
4825 	int starting_len = xdr->buf->len;
4826 	int last_segment = xdr->buf->len;
4827 	int segments = 0;
4828 	__be32 *p, tmp;
4829 	bool is_data;
4830 	loff_t pos;
4831 	u32 eof;
4832 
4833 	if (nfserr)
4834 		return nfserr;
4835 	file = read->rd_nf->nf_file;
4836 
4837 	/* eof flag, segment count */
4838 	p = xdr_reserve_space(xdr, 4 + 4);
4839 	if (!p)
4840 		return nfserr_resource;
4841 	xdr_commit_encode(xdr);
4842 
4843 	maxcount = svc_max_payload(resp->rqstp);
4844 	maxcount = min_t(unsigned long, maxcount,
4845 			 (xdr->buf->buflen - xdr->buf->len));
4846 	maxcount = min_t(unsigned long, maxcount, read->rd_length);
4847 	count    = maxcount;
4848 
4849 	eof = read->rd_offset >= i_size_read(file_inode(file));
4850 	if (eof)
4851 		goto out;
4852 
4853 	pos = vfs_llseek(file, read->rd_offset, SEEK_HOLE);
4854 	is_data = pos > read->rd_offset;
4855 
4856 	while (count > 0 && !eof) {
4857 		maxcount = count;
4858 		if (is_data)
4859 			nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof,
4860 						segments == 0 ? &pos : NULL);
4861 		else
4862 			nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
4863 		if (nfserr)
4864 			goto out;
4865 		count -= maxcount;
4866 		read->rd_offset += maxcount;
4867 		is_data = !is_data;
4868 		last_segment = xdr->buf->len;
4869 		segments++;
4870 	}
4871 
4872 out:
4873 	if (nfserr && segments == 0)
4874 		xdr_truncate_encode(xdr, starting_len);
4875 	else {
4876 		if (nfserr) {
4877 			xdr_truncate_encode(xdr, last_segment);
4878 			nfserr = nfs_ok;
4879 			eof = 0;
4880 		}
4881 		tmp = htonl(eof);
4882 		write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
4883 		tmp = htonl(segments);
4884 		write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
4885 	}
4886 
4887 	return nfserr;
4888 }
4889 
4890 static __be32
4891 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
4892 			 struct nfsd4_copy_notify *cn)
4893 {
4894 	struct xdr_stream *xdr = resp->xdr;
4895 	__be32 *p;
4896 
4897 	if (nfserr)
4898 		return nfserr;
4899 
4900 	/* 8 sec, 4 nsec */
4901 	p = xdr_reserve_space(xdr, 12);
4902 	if (!p)
4903 		return nfserr_resource;
4904 
4905 	/* cnr_lease_time */
4906 	p = xdr_encode_hyper(p, cn->cpn_sec);
4907 	*p++ = cpu_to_be32(cn->cpn_nsec);
4908 
4909 	/* cnr_stateid */
4910 	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
4911 	if (nfserr)
4912 		return nfserr;
4913 
4914 	/* cnr_src.nl_nsvr */
4915 	p = xdr_reserve_space(xdr, 4);
4916 	if (!p)
4917 		return nfserr_resource;
4918 
4919 	*p++ = cpu_to_be32(1);
4920 
4921 	return nfsd42_encode_nl4_server(resp, &cn->cpn_src);
4922 }
4923 
4924 static __be32
4925 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
4926 		  struct nfsd4_seek *seek)
4927 {
4928 	__be32 *p;
4929 
4930 	p = xdr_reserve_space(resp->xdr, 4 + 8);
4931 	*p++ = cpu_to_be32(seek->seek_eof);
4932 	p = xdr_encode_hyper(p, seek->seek_pos);
4933 
4934 	return 0;
4935 }
4936 
4937 static __be32
4938 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
4939 {
4940 	return nfserr;
4941 }
4942 
4943 /*
4944  * Encode kmalloc-ed buffer in to XDR stream.
4945  */
4946 static __be32
4947 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
4948 {
4949 	u32 cplen;
4950 	__be32 *p;
4951 
4952 	cplen = min_t(unsigned long, buflen,
4953 		      ((void *)xdr->end - (void *)xdr->p));
4954 	p = xdr_reserve_space(xdr, cplen);
4955 	if (!p)
4956 		return nfserr_resource;
4957 
4958 	memcpy(p, buf, cplen);
4959 	buf += cplen;
4960 	buflen -= cplen;
4961 
4962 	while (buflen) {
4963 		cplen = min_t(u32, buflen, PAGE_SIZE);
4964 		p = xdr_reserve_space(xdr, cplen);
4965 		if (!p)
4966 			return nfserr_resource;
4967 
4968 		memcpy(p, buf, cplen);
4969 
4970 		if (cplen < PAGE_SIZE) {
4971 			/*
4972 			 * We're done, with a length that wasn't page
4973 			 * aligned, so possibly not word aligned. Pad
4974 			 * any trailing bytes with 0.
4975 			 */
4976 			xdr_encode_opaque_fixed(p, NULL, cplen);
4977 			break;
4978 		}
4979 
4980 		buflen -= PAGE_SIZE;
4981 		buf += PAGE_SIZE;
4982 	}
4983 
4984 	return 0;
4985 }
4986 
4987 static __be32
4988 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4989 		      struct nfsd4_getxattr *getxattr)
4990 {
4991 	struct xdr_stream *xdr = resp->xdr;
4992 	__be32 *p, err;
4993 
4994 	p = xdr_reserve_space(xdr, 4);
4995 	if (!p)
4996 		return nfserr_resource;
4997 
4998 	*p = cpu_to_be32(getxattr->getxa_len);
4999 
5000 	if (getxattr->getxa_len == 0)
5001 		return 0;
5002 
5003 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
5004 				    getxattr->getxa_len);
5005 
5006 	kvfree(getxattr->getxa_buf);
5007 
5008 	return err;
5009 }
5010 
5011 static __be32
5012 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5013 		      struct nfsd4_setxattr *setxattr)
5014 {
5015 	struct xdr_stream *xdr = resp->xdr;
5016 	__be32 *p;
5017 
5018 	p = xdr_reserve_space(xdr, 20);
5019 	if (!p)
5020 		return nfserr_resource;
5021 
5022 	encode_cinfo(p, &setxattr->setxa_cinfo);
5023 
5024 	return 0;
5025 }
5026 
5027 /*
5028  * See if there are cookie values that can be rejected outright.
5029  */
5030 static __be32
5031 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5032 				u32 *offsetp)
5033 {
5034 	u64 cookie = listxattrs->lsxa_cookie;
5035 
5036 	/*
5037 	 * If the cookie is larger than the maximum number we can fit
5038 	 * in either the buffer we just got back from vfs_listxattr, or,
5039 	 * XDR-encoded, in the return buffer, it's invalid.
5040 	 */
5041 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5042 		return nfserr_badcookie;
5043 
5044 	if (cookie > (listxattrs->lsxa_maxcount /
5045 		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
5046 		return nfserr_badcookie;
5047 
5048 	*offsetp = (u32)cookie;
5049 	return 0;
5050 }
5051 
5052 static __be32
5053 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5054 			struct nfsd4_listxattrs *listxattrs)
5055 {
5056 	struct xdr_stream *xdr = resp->xdr;
5057 	u32 cookie_offset, count_offset, eof;
5058 	u32 left, xdrleft, slen, count;
5059 	u32 xdrlen, offset;
5060 	u64 cookie;
5061 	char *sp;
5062 	__be32 status, tmp;
5063 	__be32 *p;
5064 	u32 nuser;
5065 
5066 	eof = 1;
5067 
5068 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5069 	if (status)
5070 		goto out;
5071 
5072 	/*
5073 	 * Reserve space for the cookie and the name array count. Record
5074 	 * the offsets to save them later.
5075 	 */
5076 	cookie_offset = xdr->buf->len;
5077 	count_offset = cookie_offset + 8;
5078 	p = xdr_reserve_space(xdr, 12);
5079 	if (!p) {
5080 		status = nfserr_resource;
5081 		goto out;
5082 	}
5083 
5084 	count = 0;
5085 	left = listxattrs->lsxa_len;
5086 	sp = listxattrs->lsxa_buf;
5087 	nuser = 0;
5088 
5089 	xdrleft = listxattrs->lsxa_maxcount;
5090 
5091 	while (left > 0 && xdrleft > 0) {
5092 		slen = strlen(sp);
5093 
5094 		/*
5095 		 * Check if this is a "user." attribute, skip it if not.
5096 		 */
5097 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5098 			goto contloop;
5099 
5100 		slen -= XATTR_USER_PREFIX_LEN;
5101 		xdrlen = 4 + ((slen + 3) & ~3);
5102 		if (xdrlen > xdrleft) {
5103 			if (count == 0) {
5104 				/*
5105 				 * Can't even fit the first attribute name.
5106 				 */
5107 				status = nfserr_toosmall;
5108 				goto out;
5109 			}
5110 			eof = 0;
5111 			goto wreof;
5112 		}
5113 
5114 		left -= XATTR_USER_PREFIX_LEN;
5115 		sp += XATTR_USER_PREFIX_LEN;
5116 		if (nuser++ < offset)
5117 			goto contloop;
5118 
5119 
5120 		p = xdr_reserve_space(xdr, xdrlen);
5121 		if (!p) {
5122 			status = nfserr_resource;
5123 			goto out;
5124 		}
5125 
5126 		xdr_encode_opaque(p, sp, slen);
5127 
5128 		xdrleft -= xdrlen;
5129 		count++;
5130 contloop:
5131 		sp += slen + 1;
5132 		left -= slen + 1;
5133 	}
5134 
5135 	/*
5136 	 * If there were user attributes to copy, but we didn't copy
5137 	 * any, the offset was too large (e.g. the cookie was invalid).
5138 	 */
5139 	if (nuser > 0 && count == 0) {
5140 		status = nfserr_badcookie;
5141 		goto out;
5142 	}
5143 
5144 wreof:
5145 	p = xdr_reserve_space(xdr, 4);
5146 	if (!p) {
5147 		status = nfserr_resource;
5148 		goto out;
5149 	}
5150 	*p = cpu_to_be32(eof);
5151 
5152 	cookie = offset + count;
5153 
5154 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
5155 	tmp = cpu_to_be32(count);
5156 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5157 out:
5158 	if (listxattrs->lsxa_len)
5159 		kvfree(listxattrs->lsxa_buf);
5160 	return status;
5161 }
5162 
5163 static __be32
5164 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5165 			 struct nfsd4_removexattr *removexattr)
5166 {
5167 	struct xdr_stream *xdr = resp->xdr;
5168 	__be32 *p;
5169 
5170 	p = xdr_reserve_space(xdr, 20);
5171 	if (!p)
5172 		return nfserr_resource;
5173 
5174 	p = encode_cinfo(p, &removexattr->rmxa_cinfo);
5175 	return 0;
5176 }
5177 
5178 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
5179 
5180 /*
5181  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5182  * since we don't need to filter out obsolete ops as this is
5183  * done in the decoding phase.
5184  */
5185 static const nfsd4_enc nfsd4_enc_ops[] = {
5186 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
5187 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
5188 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
5189 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
5190 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
5191 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5192 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
5193 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
5194 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
5195 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
5196 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
5197 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
5198 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
5199 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
5200 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5201 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
5202 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
5203 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
5204 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
5205 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5206 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
5207 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
5208 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
5209 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
5210 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
5211 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
5212 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
5213 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
5214 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
5215 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
5216 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
5217 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
5218 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
5219 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
5220 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
5221 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
5222 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
5223 
5224 	/* NFSv4.1 operations */
5225 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
5226 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
5227 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
5228 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
5229 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
5230 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
5231 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5232 #ifdef CONFIG_NFSD_PNFS
5233 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
5234 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5235 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
5236 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
5237 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
5238 #else
5239 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
5240 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
5241 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
5242 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
5243 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
5244 #endif
5245 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
5246 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
5247 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
5248 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
5249 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
5250 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
5251 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
5252 
5253 	/* NFSv4.2 operations */
5254 	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5255 	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
5256 	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_copy_notify,
5257 	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
5258 	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
5259 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
5260 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
5261 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
5262 	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
5263 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_read_plus,
5264 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
5265 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
5266 	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
5267 
5268 	/* RFC 8276 extended atributes operations */
5269 	[OP_GETXATTR]		= (nfsd4_enc)nfsd4_encode_getxattr,
5270 	[OP_SETXATTR]		= (nfsd4_enc)nfsd4_encode_setxattr,
5271 	[OP_LISTXATTRS]		= (nfsd4_enc)nfsd4_encode_listxattrs,
5272 	[OP_REMOVEXATTR]	= (nfsd4_enc)nfsd4_encode_removexattr,
5273 };
5274 
5275 /*
5276  * Calculate whether we still have space to encode repsize bytes.
5277  * There are two considerations:
5278  *     - For NFS versions >=4.1, the size of the reply must stay within
5279  *       session limits
5280  *     - For all NFS versions, we must stay within limited preallocated
5281  *       buffer space.
5282  *
5283  * This is called before the operation is processed, so can only provide
5284  * an upper estimate.  For some nonidempotent operations (such as
5285  * getattr), it's not necessarily a problem if that estimate is wrong,
5286  * as we can fail it after processing without significant side effects.
5287  */
5288 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5289 {
5290 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5291 	struct nfsd4_slot *slot = resp->cstate.slot;
5292 
5293 	if (buf->len + respsize <= buf->buflen)
5294 		return nfs_ok;
5295 	if (!nfsd4_has_session(&resp->cstate))
5296 		return nfserr_resource;
5297 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5298 		WARN_ON_ONCE(1);
5299 		return nfserr_rep_too_big_to_cache;
5300 	}
5301 	return nfserr_rep_too_big;
5302 }
5303 
5304 void
5305 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5306 {
5307 	struct xdr_stream *xdr = resp->xdr;
5308 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5309 	struct svc_rqst *rqstp = resp->rqstp;
5310 	const struct nfsd4_operation *opdesc = op->opdesc;
5311 	int post_err_offset;
5312 	nfsd4_enc encoder;
5313 	__be32 *p;
5314 
5315 	p = xdr_reserve_space(xdr, 8);
5316 	if (!p) {
5317 		WARN_ON_ONCE(1);
5318 		return;
5319 	}
5320 	*p++ = cpu_to_be32(op->opnum);
5321 	post_err_offset = xdr->buf->len;
5322 
5323 	if (op->opnum == OP_ILLEGAL)
5324 		goto status;
5325 	if (op->status && opdesc &&
5326 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5327 		goto status;
5328 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5329 	       !nfsd4_enc_ops[op->opnum]);
5330 	encoder = nfsd4_enc_ops[op->opnum];
5331 	op->status = encoder(resp, op->status, &op->u);
5332 	if (op->status)
5333 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5334 	if (opdesc && opdesc->op_release)
5335 		opdesc->op_release(&op->u);
5336 	xdr_commit_encode(xdr);
5337 
5338 	/* nfsd4_check_resp_size guarantees enough room for error status */
5339 	if (!op->status) {
5340 		int space_needed = 0;
5341 		if (!nfsd4_last_compound_op(rqstp))
5342 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5343 		op->status = nfsd4_check_resp_size(resp, space_needed);
5344 	}
5345 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5346 		struct nfsd4_slot *slot = resp->cstate.slot;
5347 
5348 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5349 			op->status = nfserr_rep_too_big_to_cache;
5350 		else
5351 			op->status = nfserr_rep_too_big;
5352 	}
5353 	if (op->status == nfserr_resource ||
5354 	    op->status == nfserr_rep_too_big ||
5355 	    op->status == nfserr_rep_too_big_to_cache) {
5356 		/*
5357 		 * The operation may have already been encoded or
5358 		 * partially encoded.  No op returns anything additional
5359 		 * in the case of one of these three errors, so we can
5360 		 * just truncate back to after the status.  But it's a
5361 		 * bug if we had to do this on a non-idempotent op:
5362 		 */
5363 		warn_on_nonidempotent_op(op);
5364 		xdr_truncate_encode(xdr, post_err_offset);
5365 	}
5366 	if (so) {
5367 		int len = xdr->buf->len - post_err_offset;
5368 
5369 		so->so_replay.rp_status = op->status;
5370 		so->so_replay.rp_buflen = len;
5371 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5372 						so->so_replay.rp_buf, len);
5373 	}
5374 status:
5375 	/* Note that op->status is already in network byte order: */
5376 	write_bytes_to_xdr_buf(xdr->buf, post_err_offset - 4, &op->status, 4);
5377 }
5378 
5379 /*
5380  * Encode the reply stored in the stateowner reply cache
5381  *
5382  * XDR note: do not encode rp->rp_buflen: the buffer contains the
5383  * previously sent already encoded operation.
5384  */
5385 void
5386 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5387 {
5388 	__be32 *p;
5389 	struct nfs4_replay *rp = op->replay;
5390 
5391 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
5392 	if (!p) {
5393 		WARN_ON_ONCE(1);
5394 		return;
5395 	}
5396 	*p++ = cpu_to_be32(op->opnum);
5397 	*p++ = rp->rp_status;  /* already xdr'ed */
5398 
5399 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
5400 }
5401 
5402 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5403 {
5404 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5405 
5406 	if (args->ops != args->iops) {
5407 		kfree(args->ops);
5408 		args->ops = args->iops;
5409 	}
5410 	while (args->to_free) {
5411 		struct svcxdr_tmpbuf *tb = args->to_free;
5412 		args->to_free = tb->next;
5413 		kfree(tb);
5414 	}
5415 }
5416 
5417 bool
5418 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5419 {
5420 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5421 
5422 	/* svcxdr_tmp_alloc */
5423 	args->to_free = NULL;
5424 
5425 	args->xdr = xdr;
5426 	args->ops = args->iops;
5427 	args->rqstp = rqstp;
5428 
5429 	return nfsd4_decode_compound(args);
5430 }
5431 
5432 bool
5433 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5434 {
5435 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5436 	struct xdr_buf *buf = xdr->buf;
5437 	__be32 *p;
5438 
5439 	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
5440 				 buf->tail[0].iov_len);
5441 
5442 	/*
5443 	 * Send buffer space for the following items is reserved
5444 	 * at the top of nfsd4_proc_compound().
5445 	 */
5446 	p = resp->statusp;
5447 
5448 	*p++ = resp->cstate.status;
5449 
5450 	rqstp->rq_next_page = xdr->page_ptr + 1;
5451 
5452 	*p++ = htonl(resp->taglen);
5453 	memcpy(p, resp->tag, resp->taglen);
5454 	p += XDR_QUADLEN(resp->taglen);
5455 	*p++ = htonl(resp->opcnt);
5456 
5457 	nfsd4_sequence_done(resp);
5458 	return true;
5459 }
5460