xref: /openbmc/linux/fs/nfsd/nfs4xdr.c (revision a325f174)
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 <linux/vmalloc.h>
46 
47 #include <uapi/linux/xattr.h>
48 
49 #include "idmap.h"
50 #include "acl.h"
51 #include "xdr4.h"
52 #include "vfs.h"
53 #include "state.h"
54 #include "cache.h"
55 #include "netns.h"
56 #include "pnfs.h"
57 #include "filecache.h"
58 
59 #include "trace.h"
60 
61 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
62 #include <linux/security.h>
63 #endif
64 
65 
66 #define NFSDDBG_FACILITY		NFSDDBG_XDR
67 
68 const u32 nfsd_suppattrs[3][3] = {
69 	{NFSD4_SUPPORTED_ATTRS_WORD0,
70 	 NFSD4_SUPPORTED_ATTRS_WORD1,
71 	 NFSD4_SUPPORTED_ATTRS_WORD2},
72 
73 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
74 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
75 	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
76 
77 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
78 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
79 	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
80 };
81 
82 /*
83  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
84  * directory in order to indicate to the client that a filesystem boundary is present
85  * We use a fixed fsid for a referral
86  */
87 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
88 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
89 
90 static __be32
91 check_filename(char *str, int len)
92 {
93 	int i;
94 
95 	if (len == 0)
96 		return nfserr_inval;
97 	if (len > NFS4_MAXNAMLEN)
98 		return nfserr_nametoolong;
99 	if (isdotent(str, len))
100 		return nfserr_badname;
101 	for (i = 0; i < len; i++)
102 		if (str[i] == '/')
103 			return nfserr_badname;
104 	return 0;
105 }
106 
107 static int zero_clientid(clientid_t *clid)
108 {
109 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
110 }
111 
112 /**
113  * svcxdr_tmpalloc - allocate memory to be freed after compound processing
114  * @argp: NFSv4 compound argument structure
115  * @len: length of buffer to allocate
116  *
117  * Allocates a buffer of size @len to be freed when processing the compound
118  * operation described in @argp finishes.
119  */
120 static void *
121 svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
122 {
123 	struct svcxdr_tmpbuf *tb;
124 
125 	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
126 	if (!tb)
127 		return NULL;
128 	tb->next = argp->to_free;
129 	argp->to_free = tb;
130 	return tb->buf;
131 }
132 
133 /*
134  * For xdr strings that need to be passed to other kernel api's
135  * as null-terminated strings.
136  *
137  * Note null-terminating in place usually isn't safe since the
138  * buffer might end on a page boundary.
139  */
140 static char *
141 svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
142 {
143 	char *p = svcxdr_tmpalloc(argp, len + 1);
144 
145 	if (!p)
146 		return NULL;
147 	memcpy(p, buf, len);
148 	p[len] = '\0';
149 	return p;
150 }
151 
152 static void *
153 svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, u32 len)
154 {
155 	__be32 *tmp;
156 
157 	/*
158 	 * The location of the decoded data item is stable,
159 	 * so @p is OK to use. This is the common case.
160 	 */
161 	if (p != argp->xdr->scratch.iov_base)
162 		return p;
163 
164 	tmp = svcxdr_tmpalloc(argp, len);
165 	if (!tmp)
166 		return NULL;
167 	memcpy(tmp, p, len);
168 	return tmp;
169 }
170 
171 /*
172  * NFSv4 basic data type decoders
173  */
174 
175 /*
176  * This helper handles variable-length opaques which belong to protocol
177  * elements that this implementation does not support.
178  */
179 static __be32
180 nfsd4_decode_ignored_string(struct nfsd4_compoundargs *argp, u32 maxlen)
181 {
182 	u32 len;
183 
184 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
185 		return nfserr_bad_xdr;
186 	if (maxlen && len > maxlen)
187 		return nfserr_bad_xdr;
188 	if (!xdr_inline_decode(argp->xdr, len))
189 		return nfserr_bad_xdr;
190 
191 	return nfs_ok;
192 }
193 
194 static __be32
195 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
196 {
197 	__be32 *p;
198 	u32 len;
199 
200 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
201 		return nfserr_bad_xdr;
202 	if (len == 0 || len > NFS4_OPAQUE_LIMIT)
203 		return nfserr_bad_xdr;
204 	p = xdr_inline_decode(argp->xdr, len);
205 	if (!p)
206 		return nfserr_bad_xdr;
207 	o->data = svcxdr_savemem(argp, p, len);
208 	if (!o->data)
209 		return nfserr_jukebox;
210 	o->len = len;
211 
212 	return nfs_ok;
213 }
214 
215 static __be32
216 nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
217 {
218 	__be32 *p, status;
219 
220 	if (xdr_stream_decode_u32(argp->xdr, lenp) < 0)
221 		return nfserr_bad_xdr;
222 	p = xdr_inline_decode(argp->xdr, *lenp);
223 	if (!p)
224 		return nfserr_bad_xdr;
225 	status = check_filename((char *)p, *lenp);
226 	if (status)
227 		return status;
228 	*namp = svcxdr_savemem(argp, p, *lenp);
229 	if (!*namp)
230 		return nfserr_jukebox;
231 
232 	return nfs_ok;
233 }
234 
235 static __be32
236 nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
237 {
238 	__be32 *p;
239 
240 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
241 	if (!p)
242 		return nfserr_bad_xdr;
243 	p = xdr_decode_hyper(p, &tv->tv_sec);
244 	tv->tv_nsec = be32_to_cpup(p++);
245 	if (tv->tv_nsec >= (u32)1000000000)
246 		return nfserr_inval;
247 	return nfs_ok;
248 }
249 
250 static __be32
251 nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
252 {
253 	__be32 *p;
254 
255 	p = xdr_inline_decode(argp->xdr, NFS4_VERIFIER_SIZE);
256 	if (!p)
257 		return nfserr_bad_xdr;
258 	memcpy(verf->data, p, sizeof(verf->data));
259 	return nfs_ok;
260 }
261 
262 /**
263  * nfsd4_decode_bitmap4 - Decode an NFSv4 bitmap4
264  * @argp: NFSv4 compound argument structure
265  * @bmval: pointer to an array of u32's to decode into
266  * @bmlen: size of the @bmval array
267  *
268  * The server needs to return nfs_ok rather than nfserr_bad_xdr when
269  * encountering bitmaps containing bits it does not recognize. This
270  * includes bits in bitmap words past WORDn, where WORDn is the last
271  * bitmap WORD the implementation currently supports. Thus we are
272  * careful here to simply ignore bits in bitmap words that this
273  * implementation has yet to support explicitly.
274  *
275  * Return values:
276  *   %nfs_ok: @bmval populated successfully
277  *   %nfserr_bad_xdr: the encoded bitmap was invalid
278  */
279 static __be32
280 nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
281 {
282 	ssize_t status;
283 
284 	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
285 	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
286 }
287 
288 static __be32
289 nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
290 {
291 	__be32 *p, status;
292 	u32 length;
293 
294 	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
295 		return nfserr_bad_xdr;
296 	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
297 		return nfserr_bad_xdr;
298 	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
299 		return nfserr_bad_xdr;
300 
301 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
302 		return nfserr_bad_xdr;
303 	p = xdr_inline_decode(argp->xdr, length);
304 	if (!p)
305 		return nfserr_bad_xdr;
306 	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
307 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
308 		status = nfs_ok;
309 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
310 		status = nfsd_map_name_to_gid(argp->rqstp,
311 				(char *)p, length, &ace->who_gid);
312 	else
313 		status = nfsd_map_name_to_uid(argp->rqstp,
314 				(char *)p, length, &ace->who_uid);
315 
316 	return status;
317 }
318 
319 /* A counted array of nfsace4's */
320 static noinline __be32
321 nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
322 {
323 	struct nfs4_ace *ace;
324 	__be32 status;
325 	u32 count;
326 
327 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
328 		return nfserr_bad_xdr;
329 
330 	if (count > xdr_stream_remaining(argp->xdr) / 20)
331 		/*
332 		 * Even with 4-byte names there wouldn't be
333 		 * space for that many aces; something fishy is
334 		 * going on:
335 		 */
336 		return nfserr_fbig;
337 
338 	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
339 	if (*acl == NULL)
340 		return nfserr_jukebox;
341 
342 	(*acl)->naces = count;
343 	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
344 		status = nfsd4_decode_nfsace4(argp, ace);
345 		if (status)
346 			return status;
347 	}
348 
349 	return nfs_ok;
350 }
351 
352 static noinline __be32
353 nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
354 			    struct xdr_netobj *label)
355 {
356 	u32 lfs, pi, length;
357 	__be32 *p;
358 
359 	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
360 		return nfserr_bad_xdr;
361 	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
362 		return nfserr_bad_xdr;
363 
364 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
365 		return nfserr_bad_xdr;
366 	if (length > NFS4_MAXLABELLEN)
367 		return nfserr_badlabel;
368 	p = xdr_inline_decode(argp->xdr, length);
369 	if (!p)
370 		return nfserr_bad_xdr;
371 	label->len = length;
372 	label->data = svcxdr_dupstr(argp, p, length);
373 	if (!label->data)
374 		return nfserr_jukebox;
375 
376 	return nfs_ok;
377 }
378 
379 static __be32
380 nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
381 		    struct iattr *iattr, struct nfs4_acl **acl,
382 		    struct xdr_netobj *label, int *umask)
383 {
384 	unsigned int starting_pos;
385 	u32 attrlist4_count;
386 	__be32 *p, status;
387 
388 	iattr->ia_valid = 0;
389 	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
390 	if (status)
391 		return nfserr_bad_xdr;
392 
393 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
394 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
395 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
396 		if (nfsd_attrs_supported(argp->minorversion, bmval))
397 			return nfserr_inval;
398 		return nfserr_attrnotsupp;
399 	}
400 
401 	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
402 		return nfserr_bad_xdr;
403 	starting_pos = xdr_stream_pos(argp->xdr);
404 
405 	if (bmval[0] & FATTR4_WORD0_SIZE) {
406 		u64 size;
407 
408 		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
409 			return nfserr_bad_xdr;
410 		iattr->ia_size = size;
411 		iattr->ia_valid |= ATTR_SIZE;
412 	}
413 	if (bmval[0] & FATTR4_WORD0_ACL) {
414 		status = nfsd4_decode_acl(argp, acl);
415 		if (status)
416 			return status;
417 	} else
418 		*acl = NULL;
419 	if (bmval[1] & FATTR4_WORD1_MODE) {
420 		u32 mode;
421 
422 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
423 			return nfserr_bad_xdr;
424 		iattr->ia_mode = mode;
425 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
426 		iattr->ia_valid |= ATTR_MODE;
427 	}
428 	if (bmval[1] & FATTR4_WORD1_OWNER) {
429 		u32 length;
430 
431 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
432 			return nfserr_bad_xdr;
433 		p = xdr_inline_decode(argp->xdr, length);
434 		if (!p)
435 			return nfserr_bad_xdr;
436 		status = nfsd_map_name_to_uid(argp->rqstp, (char *)p, length,
437 					      &iattr->ia_uid);
438 		if (status)
439 			return status;
440 		iattr->ia_valid |= ATTR_UID;
441 	}
442 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
443 		u32 length;
444 
445 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
446 			return nfserr_bad_xdr;
447 		p = xdr_inline_decode(argp->xdr, length);
448 		if (!p)
449 			return nfserr_bad_xdr;
450 		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
451 					      &iattr->ia_gid);
452 		if (status)
453 			return status;
454 		iattr->ia_valid |= ATTR_GID;
455 	}
456 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
457 		u32 set_it;
458 
459 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
460 			return nfserr_bad_xdr;
461 		switch (set_it) {
462 		case NFS4_SET_TO_CLIENT_TIME:
463 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
464 			if (status)
465 				return status;
466 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
467 			break;
468 		case NFS4_SET_TO_SERVER_TIME:
469 			iattr->ia_valid |= ATTR_ATIME;
470 			break;
471 		default:
472 			return nfserr_bad_xdr;
473 		}
474 	}
475 	if (bmval[1] & FATTR4_WORD1_TIME_CREATE) {
476 		struct timespec64 ts;
477 
478 		/* No Linux filesystem supports setting this attribute. */
479 		bmval[1] &= ~FATTR4_WORD1_TIME_CREATE;
480 		status = nfsd4_decode_nfstime4(argp, &ts);
481 		if (status)
482 			return status;
483 	}
484 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
485 		u32 set_it;
486 
487 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
488 			return nfserr_bad_xdr;
489 		switch (set_it) {
490 		case NFS4_SET_TO_CLIENT_TIME:
491 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
492 			if (status)
493 				return status;
494 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
495 			break;
496 		case NFS4_SET_TO_SERVER_TIME:
497 			iattr->ia_valid |= ATTR_MTIME;
498 			break;
499 		default:
500 			return nfserr_bad_xdr;
501 		}
502 	}
503 	label->len = 0;
504 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
505 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
506 		status = nfsd4_decode_security_label(argp, label);
507 		if (status)
508 			return status;
509 	}
510 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
511 		u32 mode, mask;
512 
513 		if (!umask)
514 			return nfserr_bad_xdr;
515 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
516 			return nfserr_bad_xdr;
517 		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
518 		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
519 			return nfserr_bad_xdr;
520 		*umask = mask & S_IRWXUGO;
521 		iattr->ia_valid |= ATTR_MODE;
522 	}
523 
524 	/* request sanity: did attrlist4 contain the expected number of words? */
525 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
526 		return nfserr_bad_xdr;
527 
528 	return nfs_ok;
529 }
530 
531 static __be32
532 nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
533 {
534 	__be32 *p;
535 
536 	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
537 	if (!p)
538 		return nfserr_bad_xdr;
539 	sid->si_generation = be32_to_cpup(p++);
540 	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
541 	return nfs_ok;
542 }
543 
544 static __be32
545 nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
546 {
547 	__be32 *p;
548 
549 	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
550 	if (!p)
551 		return nfserr_bad_xdr;
552 	memcpy(clientid, p, sizeof(*clientid));
553 	return nfs_ok;
554 }
555 
556 static __be32
557 nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
558 			  clientid_t *clientid, struct xdr_netobj *owner)
559 {
560 	__be32 status;
561 
562 	status = nfsd4_decode_clientid4(argp, clientid);
563 	if (status)
564 		return status;
565 	return nfsd4_decode_opaque(argp, owner);
566 }
567 
568 #ifdef CONFIG_NFSD_PNFS
569 static __be32
570 nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
571 		       struct nfsd4_deviceid *devid)
572 {
573 	__be32 *p;
574 
575 	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
576 	if (!p)
577 		return nfserr_bad_xdr;
578 	memcpy(devid, p, sizeof(*devid));
579 	return nfs_ok;
580 }
581 
582 static __be32
583 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
584 			   struct nfsd4_layoutcommit *lcp)
585 {
586 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
587 		return nfserr_bad_xdr;
588 	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
589 		return nfserr_bad_xdr;
590 	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
591 		return nfserr_bad_xdr;
592 
593 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
594 		return nfserr_bad_xdr;
595 	if (lcp->lc_up_len > 0) {
596 		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
597 		if (!lcp->lc_up_layout)
598 			return nfserr_bad_xdr;
599 	}
600 
601 	return nfs_ok;
602 }
603 
604 static __be32
605 nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
606 			   struct nfsd4_layoutreturn *lrp)
607 {
608 	__be32 status;
609 
610 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
611 		return nfserr_bad_xdr;
612 	switch (lrp->lr_return_type) {
613 	case RETURN_FILE:
614 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
615 			return nfserr_bad_xdr;
616 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
617 			return nfserr_bad_xdr;
618 		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
619 		if (status)
620 			return status;
621 		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
622 			return nfserr_bad_xdr;
623 		if (lrp->lrf_body_len > 0) {
624 			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
625 			if (!lrp->lrf_body)
626 				return nfserr_bad_xdr;
627 		}
628 		break;
629 	case RETURN_FSID:
630 	case RETURN_ALL:
631 		lrp->lr_seg.offset = 0;
632 		lrp->lr_seg.length = NFS4_MAX_UINT64;
633 		break;
634 	default:
635 		return nfserr_bad_xdr;
636 	}
637 
638 	return nfs_ok;
639 }
640 
641 #endif /* CONFIG_NFSD_PNFS */
642 
643 static __be32
644 nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
645 			struct nfs4_sessionid *sessionid)
646 {
647 	__be32 *p;
648 
649 	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
650 	if (!p)
651 		return nfserr_bad_xdr;
652 	memcpy(sessionid->data, p, sizeof(sessionid->data));
653 	return nfs_ok;
654 }
655 
656 /* Defined in Appendix A of RFC 5531 */
657 static __be32
658 nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
659 			   struct nfsd4_cb_sec *cbs)
660 {
661 	u32 stamp, gidcount, uid, gid;
662 	__be32 *p, status;
663 
664 	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
665 		return nfserr_bad_xdr;
666 	/* machine name */
667 	status = nfsd4_decode_ignored_string(argp, 255);
668 	if (status)
669 		return status;
670 	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
671 		return nfserr_bad_xdr;
672 	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
673 		return nfserr_bad_xdr;
674 	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
675 		return nfserr_bad_xdr;
676 	if (gidcount > 16)
677 		return nfserr_bad_xdr;
678 	p = xdr_inline_decode(argp->xdr, gidcount << 2);
679 	if (!p)
680 		return nfserr_bad_xdr;
681 	if (cbs->flavor == (u32)(-1)) {
682 		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
683 
684 		kuid_t kuid = make_kuid(userns, uid);
685 		kgid_t kgid = make_kgid(userns, gid);
686 		if (uid_valid(kuid) && gid_valid(kgid)) {
687 			cbs->uid = kuid;
688 			cbs->gid = kgid;
689 			cbs->flavor = RPC_AUTH_UNIX;
690 		} else {
691 			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
692 		}
693 	}
694 
695 	return nfs_ok;
696 }
697 
698 static __be32
699 nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
700 			     struct nfsd4_cb_sec *cbs)
701 {
702 	__be32 status;
703 	u32 service;
704 
705 	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
706 
707 	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
708 		return nfserr_bad_xdr;
709 	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
710 		return nfserr_bad_xdr;
711 	/* gcbp_handle_from_server */
712 	status = nfsd4_decode_ignored_string(argp, 0);
713 	if (status)
714 		return status;
715 	/* gcbp_handle_from_client */
716 	status = nfsd4_decode_ignored_string(argp, 0);
717 	if (status)
718 		return status;
719 
720 	return nfs_ok;
721 }
722 
723 /* a counted array of callback_sec_parms4 items */
724 static __be32
725 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
726 {
727 	u32 i, secflavor, nr_secflavs;
728 	__be32 status;
729 
730 	/* callback_sec_params4 */
731 	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
732 		return nfserr_bad_xdr;
733 	if (nr_secflavs)
734 		cbs->flavor = (u32)(-1);
735 	else
736 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
737 		cbs->flavor = 0;
738 
739 	for (i = 0; i < nr_secflavs; ++i) {
740 		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
741 			return nfserr_bad_xdr;
742 		switch (secflavor) {
743 		case RPC_AUTH_NULL:
744 			/* void */
745 			if (cbs->flavor == (u32)(-1))
746 				cbs->flavor = RPC_AUTH_NULL;
747 			break;
748 		case RPC_AUTH_UNIX:
749 			status = nfsd4_decode_authsys_parms(argp, cbs);
750 			if (status)
751 				return status;
752 			break;
753 		case RPC_AUTH_GSS:
754 			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
755 			if (status)
756 				return status;
757 			break;
758 		default:
759 			return nfserr_inval;
760 		}
761 	}
762 
763 	return nfs_ok;
764 }
765 
766 
767 /*
768  * NFSv4 operation argument decoders
769  */
770 
771 static __be32
772 nfsd4_decode_access(struct nfsd4_compoundargs *argp,
773 		    union nfsd4_op_u *u)
774 {
775 	struct nfsd4_access *access = &u->access;
776 	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
777 		return nfserr_bad_xdr;
778 	return nfs_ok;
779 }
780 
781 static __be32
782 nfsd4_decode_close(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
783 {
784 	struct nfsd4_close *close = &u->close;
785 	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
786 		return nfserr_bad_xdr;
787 	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
788 }
789 
790 
791 static __be32
792 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
793 {
794 	struct nfsd4_commit *commit = &u->commit;
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 	memset(&commit->co_verf, 0, sizeof(commit->co_verf));
800 	return nfs_ok;
801 }
802 
803 static __be32
804 nfsd4_decode_create(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
805 {
806 	struct nfsd4_create *create = &u->create;
807 	__be32 *p, status;
808 
809 	memset(create, 0, sizeof(*create));
810 	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
811 		return nfserr_bad_xdr;
812 	switch (create->cr_type) {
813 	case NF4LNK:
814 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
815 			return nfserr_bad_xdr;
816 		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
817 		if (!p)
818 			return nfserr_bad_xdr;
819 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
820 		if (!create->cr_data)
821 			return nfserr_jukebox;
822 		break;
823 	case NF4BLK:
824 	case NF4CHR:
825 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
826 			return nfserr_bad_xdr;
827 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
828 			return nfserr_bad_xdr;
829 		break;
830 	case NF4SOCK:
831 	case NF4FIFO:
832 	case NF4DIR:
833 	default:
834 		break;
835 	}
836 	status = nfsd4_decode_component4(argp, &create->cr_name,
837 					 &create->cr_namelen);
838 	if (status)
839 		return status;
840 	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
841 				    ARRAY_SIZE(create->cr_bmval),
842 				    &create->cr_iattr, &create->cr_acl,
843 				    &create->cr_label, &create->cr_umask);
844 	if (status)
845 		return status;
846 
847 	return nfs_ok;
848 }
849 
850 static inline __be32
851 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
852 {
853 	struct nfsd4_delegreturn *dr = &u->delegreturn;
854 	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
855 }
856 
857 static inline __be32
858 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
859 {
860 	struct nfsd4_getattr *getattr = &u->getattr;
861 	memset(getattr, 0, sizeof(*getattr));
862 	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
863 				    ARRAY_SIZE(getattr->ga_bmval));
864 }
865 
866 static __be32
867 nfsd4_decode_link(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
868 {
869 	struct nfsd4_link *link = &u->link;
870 	memset(link, 0, sizeof(*link));
871 	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
872 }
873 
874 static __be32
875 nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
876 				 struct nfsd4_lock *lock)
877 {
878 	__be32 status;
879 
880 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
881 		return nfserr_bad_xdr;
882 	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
883 	if (status)
884 		return status;
885 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
886 		return nfserr_bad_xdr;
887 	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
888 					 &lock->lk_new_owner);
889 }
890 
891 static __be32
892 nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
893 			       struct nfsd4_lock *lock)
894 {
895 	__be32 status;
896 
897 	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
898 	if (status)
899 		return status;
900 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
901 		return nfserr_bad_xdr;
902 
903 	return nfs_ok;
904 }
905 
906 static __be32
907 nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
908 {
909 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
910 		return nfserr_bad_xdr;
911 	if (lock->lk_is_new)
912 		return nfsd4_decode_open_to_lock_owner4(argp, lock);
913 	return nfsd4_decode_exist_lock_owner4(argp, lock);
914 }
915 
916 static __be32
917 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
918 {
919 	struct nfsd4_lock *lock = &u->lock;
920 	memset(lock, 0, sizeof(*lock));
921 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
922 		return nfserr_bad_xdr;
923 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
924 		return nfserr_bad_xdr;
925 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
926 		return nfserr_bad_xdr;
927 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
928 		return nfserr_bad_xdr;
929 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
930 		return nfserr_bad_xdr;
931 	return nfsd4_decode_locker4(argp, lock);
932 }
933 
934 static __be32
935 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
936 {
937 	struct nfsd4_lockt *lockt = &u->lockt;
938 	memset(lockt, 0, sizeof(*lockt));
939 	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
940 		return nfserr_bad_xdr;
941 	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
942 		return nfserr_bad_xdr;
943 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
944 		return nfserr_bad_xdr;
945 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
946 		return nfserr_bad_xdr;
947 	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
948 					 &lockt->lt_owner);
949 }
950 
951 static __be32
952 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
953 {
954 	struct nfsd4_locku *locku = &u->locku;
955 	__be32 status;
956 
957 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
958 		return nfserr_bad_xdr;
959 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
960 		return nfserr_bad_xdr;
961 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
962 		return nfserr_bad_xdr;
963 	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
964 	if (status)
965 		return status;
966 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
967 		return nfserr_bad_xdr;
968 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
969 		return nfserr_bad_xdr;
970 
971 	return nfs_ok;
972 }
973 
974 static __be32
975 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
976 {
977 	struct nfsd4_lookup *lookup = &u->lookup;
978 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
979 }
980 
981 static __be32
982 nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
983 {
984 	__be32 status;
985 
986 	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
987 		return nfserr_bad_xdr;
988 	switch (open->op_createmode) {
989 	case NFS4_CREATE_UNCHECKED:
990 	case NFS4_CREATE_GUARDED:
991 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
992 					     ARRAY_SIZE(open->op_bmval),
993 					     &open->op_iattr, &open->op_acl,
994 					     &open->op_label, &open->op_umask);
995 		if (status)
996 			return status;
997 		break;
998 	case NFS4_CREATE_EXCLUSIVE:
999 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
1000 		if (status)
1001 			return status;
1002 		break;
1003 	case NFS4_CREATE_EXCLUSIVE4_1:
1004 		if (argp->minorversion < 1)
1005 			return nfserr_bad_xdr;
1006 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
1007 		if (status)
1008 			return status;
1009 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
1010 					     ARRAY_SIZE(open->op_bmval),
1011 					     &open->op_iattr, &open->op_acl,
1012 					     &open->op_label, &open->op_umask);
1013 		if (status)
1014 			return status;
1015 		break;
1016 	default:
1017 		return nfserr_bad_xdr;
1018 	}
1019 
1020 	return nfs_ok;
1021 }
1022 
1023 static __be32
1024 nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1025 {
1026 	__be32 status;
1027 
1028 	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
1029 		return nfserr_bad_xdr;
1030 	switch (open->op_create) {
1031 	case NFS4_OPEN_NOCREATE:
1032 		break;
1033 	case NFS4_OPEN_CREATE:
1034 		status = nfsd4_decode_createhow4(argp, open);
1035 		if (status)
1036 			return status;
1037 		break;
1038 	default:
1039 		return nfserr_bad_xdr;
1040 	}
1041 
1042 	return nfs_ok;
1043 }
1044 
1045 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
1046 {
1047 	u32 w;
1048 
1049 	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
1050 		return nfserr_bad_xdr;
1051 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
1052 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
1053 	if (deleg_when)
1054 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
1055 
1056 	switch (w & NFS4_SHARE_ACCESS_MASK) {
1057 	case NFS4_SHARE_ACCESS_READ:
1058 	case NFS4_SHARE_ACCESS_WRITE:
1059 	case NFS4_SHARE_ACCESS_BOTH:
1060 		break;
1061 	default:
1062 		return nfserr_bad_xdr;
1063 	}
1064 	w &= ~NFS4_SHARE_ACCESS_MASK;
1065 	if (!w)
1066 		return nfs_ok;
1067 	if (!argp->minorversion)
1068 		return nfserr_bad_xdr;
1069 	switch (w & NFS4_SHARE_WANT_MASK) {
1070 	case NFS4_SHARE_WANT_NO_PREFERENCE:
1071 	case NFS4_SHARE_WANT_READ_DELEG:
1072 	case NFS4_SHARE_WANT_WRITE_DELEG:
1073 	case NFS4_SHARE_WANT_ANY_DELEG:
1074 	case NFS4_SHARE_WANT_NO_DELEG:
1075 	case NFS4_SHARE_WANT_CANCEL:
1076 		break;
1077 	default:
1078 		return nfserr_bad_xdr;
1079 	}
1080 	w &= ~NFS4_SHARE_WANT_MASK;
1081 	if (!w)
1082 		return nfs_ok;
1083 
1084 	if (!deleg_when)	/* open_downgrade */
1085 		return nfserr_inval;
1086 	switch (w) {
1087 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
1088 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
1089 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
1090 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
1091 		return nfs_ok;
1092 	}
1093 	return nfserr_bad_xdr;
1094 }
1095 
1096 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
1097 {
1098 	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
1099 		return nfserr_bad_xdr;
1100 	/* Note: unlike access bits, deny bits may be zero. */
1101 	if (*x & ~NFS4_SHARE_DENY_BOTH)
1102 		return nfserr_bad_xdr;
1103 
1104 	return nfs_ok;
1105 }
1106 
1107 static __be32
1108 nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
1109 			 struct nfsd4_open *open)
1110 {
1111 	__be32 status;
1112 
1113 	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
1114 		return nfserr_bad_xdr;
1115 	switch (open->op_claim_type) {
1116 	case NFS4_OPEN_CLAIM_NULL:
1117 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
1118 		status = nfsd4_decode_component4(argp, &open->op_fname,
1119 						 &open->op_fnamelen);
1120 		if (status)
1121 			return status;
1122 		break;
1123 	case NFS4_OPEN_CLAIM_PREVIOUS:
1124 		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
1125 			return nfserr_bad_xdr;
1126 		break;
1127 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
1128 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1129 		if (status)
1130 			return status;
1131 		status = nfsd4_decode_component4(argp, &open->op_fname,
1132 						 &open->op_fnamelen);
1133 		if (status)
1134 			return status;
1135 		break;
1136 	case NFS4_OPEN_CLAIM_FH:
1137 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1138 		if (argp->minorversion < 1)
1139 			return nfserr_bad_xdr;
1140 		/* void */
1141 		break;
1142 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1143 		if (argp->minorversion < 1)
1144 			return nfserr_bad_xdr;
1145 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1146 		if (status)
1147 			return status;
1148 		break;
1149 	default:
1150 		return nfserr_bad_xdr;
1151 	}
1152 
1153 	return nfs_ok;
1154 }
1155 
1156 static __be32
1157 nfsd4_decode_open(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1158 {
1159 	struct nfsd4_open *open = &u->open;
1160 	__be32 status;
1161 	u32 dummy;
1162 
1163 	memset(open, 0, sizeof(*open));
1164 
1165 	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
1166 		return nfserr_bad_xdr;
1167 	/* deleg_want is ignored */
1168 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
1169 					   &open->op_deleg_want, &dummy);
1170 	if (status)
1171 		return status;
1172 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
1173 	if (status)
1174 		return status;
1175 	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
1176 					   &open->op_owner);
1177 	if (status)
1178 		return status;
1179 	status = nfsd4_decode_openflag4(argp, open);
1180 	if (status)
1181 		return status;
1182 	return nfsd4_decode_open_claim4(argp, open);
1183 }
1184 
1185 static __be32
1186 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp,
1187 			  union nfsd4_op_u *u)
1188 {
1189 	struct nfsd4_open_confirm *open_conf = &u->open_confirm;
1190 	__be32 status;
1191 
1192 	if (argp->minorversion >= 1)
1193 		return nfserr_notsupp;
1194 
1195 	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
1196 	if (status)
1197 		return status;
1198 	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
1199 		return nfserr_bad_xdr;
1200 
1201 	memset(&open_conf->oc_resp_stateid, 0,
1202 	       sizeof(open_conf->oc_resp_stateid));
1203 	return nfs_ok;
1204 }
1205 
1206 static __be32
1207 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp,
1208 			    union nfsd4_op_u *u)
1209 {
1210 	struct nfsd4_open_downgrade *open_down = &u->open_downgrade;
1211 	__be32 status;
1212 
1213 	memset(open_down, 0, sizeof(*open_down));
1214 	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
1215 	if (status)
1216 		return status;
1217 	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
1218 		return nfserr_bad_xdr;
1219 	/* deleg_want is ignored */
1220 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1221 					   &open_down->od_deleg_want, NULL);
1222 	if (status)
1223 		return status;
1224 	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1225 }
1226 
1227 static __be32
1228 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1229 {
1230 	struct nfsd4_putfh *putfh = &u->putfh;
1231 	__be32 *p;
1232 
1233 	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
1234 		return nfserr_bad_xdr;
1235 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1236 		return nfserr_bad_xdr;
1237 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
1238 	if (!p)
1239 		return nfserr_bad_xdr;
1240 	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
1241 	if (!putfh->pf_fhval)
1242 		return nfserr_jukebox;
1243 
1244 	putfh->no_verify = false;
1245 	return nfs_ok;
1246 }
1247 
1248 static __be32
1249 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
1250 {
1251 	if (argp->minorversion == 0)
1252 		return nfs_ok;
1253 	return nfserr_notsupp;
1254 }
1255 
1256 static __be32
1257 nfsd4_decode_read(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1258 {
1259 	struct nfsd4_read *read = &u->read;
1260 	__be32 status;
1261 
1262 	memset(read, 0, sizeof(*read));
1263 	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
1264 	if (status)
1265 		return status;
1266 	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
1267 		return nfserr_bad_xdr;
1268 	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
1269 		return nfserr_bad_xdr;
1270 
1271 	return nfs_ok;
1272 }
1273 
1274 static __be32
1275 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1276 {
1277 	struct nfsd4_readdir *readdir = &u->readdir;
1278 	__be32 status;
1279 
1280 	memset(readdir, 0, sizeof(*readdir));
1281 	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
1282 		return nfserr_bad_xdr;
1283 	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
1284 	if (status)
1285 		return status;
1286 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
1287 		return nfserr_bad_xdr;
1288 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
1289 		return nfserr_bad_xdr;
1290 	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
1291 					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
1292 		return nfserr_bad_xdr;
1293 
1294 	return nfs_ok;
1295 }
1296 
1297 static __be32
1298 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1299 {
1300 	struct nfsd4_remove *remove = &u->remove;
1301 	memset(&remove->rm_cinfo, 0, sizeof(remove->rm_cinfo));
1302 	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
1303 }
1304 
1305 static __be32
1306 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1307 {
1308 	struct nfsd4_rename *rename = &u->rename;
1309 	__be32 status;
1310 
1311 	memset(rename, 0, sizeof(*rename));
1312 	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
1313 	if (status)
1314 		return status;
1315 	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
1316 }
1317 
1318 static __be32
1319 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1320 {
1321 	clientid_t *clientid = &u->renew;
1322 	return nfsd4_decode_clientid4(argp, clientid);
1323 }
1324 
1325 static __be32
1326 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1327 		     union nfsd4_op_u *u)
1328 {
1329 	struct nfsd4_secinfo *secinfo = &u->secinfo;
1330 	secinfo->si_exp = NULL;
1331 	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
1332 }
1333 
1334 static __be32
1335 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1336 {
1337 	struct nfsd4_setattr *setattr = &u->setattr;
1338 	__be32 status;
1339 
1340 	memset(setattr, 0, sizeof(*setattr));
1341 	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
1342 	if (status)
1343 		return status;
1344 	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
1345 				   ARRAY_SIZE(setattr->sa_bmval),
1346 				   &setattr->sa_iattr, &setattr->sa_acl,
1347 				   &setattr->sa_label, NULL);
1348 }
1349 
1350 static __be32
1351 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1352 {
1353 	struct nfsd4_setclientid *setclientid = &u->setclientid;
1354 	__be32 *p, status;
1355 
1356 	memset(setclientid, 0, sizeof(*setclientid));
1357 
1358 	if (argp->minorversion >= 1)
1359 		return nfserr_notsupp;
1360 
1361 	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
1362 	if (status)
1363 		return status;
1364 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1365 	if (status)
1366 		return status;
1367 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
1368 		return nfserr_bad_xdr;
1369 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
1370 		return nfserr_bad_xdr;
1371 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
1372 	if (!p)
1373 		return nfserr_bad_xdr;
1374 	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
1375 						setclientid->se_callback_netid_len);
1376 	if (!setclientid->se_callback_netid_val)
1377 		return nfserr_jukebox;
1378 
1379 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
1380 		return nfserr_bad_xdr;
1381 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
1382 	if (!p)
1383 		return nfserr_bad_xdr;
1384 	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
1385 						setclientid->se_callback_addr_len);
1386 	if (!setclientid->se_callback_addr_val)
1387 		return nfserr_jukebox;
1388 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
1389 		return nfserr_bad_xdr;
1390 
1391 	return nfs_ok;
1392 }
1393 
1394 static __be32
1395 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp,
1396 				 union nfsd4_op_u *u)
1397 {
1398 	struct nfsd4_setclientid_confirm *scd_c = &u->setclientid_confirm;
1399 	__be32 status;
1400 
1401 	if (argp->minorversion >= 1)
1402 		return nfserr_notsupp;
1403 
1404 	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
1405 	if (status)
1406 		return status;
1407 	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
1408 }
1409 
1410 /* Also used for NVERIFY */
1411 static __be32
1412 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1413 {
1414 	struct nfsd4_verify *verify = &u->verify;
1415 	__be32 *p, status;
1416 
1417 	memset(verify, 0, sizeof(*verify));
1418 
1419 	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
1420 				      ARRAY_SIZE(verify->ve_bmval));
1421 	if (status)
1422 		return status;
1423 
1424 	/* For convenience's sake, we compare raw xdr'd attributes in
1425 	 * nfsd4_proc_verify */
1426 
1427 	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
1428 		return nfserr_bad_xdr;
1429 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
1430 	if (!p)
1431 		return nfserr_bad_xdr;
1432 	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
1433 	if (!verify->ve_attrval)
1434 		return nfserr_jukebox;
1435 
1436 	return nfs_ok;
1437 }
1438 
1439 static __be32
1440 nfsd4_decode_write(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1441 {
1442 	struct nfsd4_write *write = &u->write;
1443 	__be32 status;
1444 
1445 	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
1446 	if (status)
1447 		return status;
1448 	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
1449 		return nfserr_bad_xdr;
1450 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
1451 		return nfserr_bad_xdr;
1452 	if (write->wr_stable_how > NFS_FILE_SYNC)
1453 		return nfserr_bad_xdr;
1454 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
1455 		return nfserr_bad_xdr;
1456 	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
1457 		return nfserr_bad_xdr;
1458 
1459 	write->wr_bytes_written = 0;
1460 	write->wr_how_written = 0;
1461 	memset(&write->wr_verifier, 0, sizeof(write->wr_verifier));
1462 	return nfs_ok;
1463 }
1464 
1465 static __be32
1466 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp,
1467 			       union nfsd4_op_u *u)
1468 {
1469 	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
1470 	__be32 status;
1471 
1472 	if (argp->minorversion >= 1)
1473 		return nfserr_notsupp;
1474 
1475 	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
1476 					   &rlockowner->rl_owner);
1477 	if (status)
1478 		return status;
1479 
1480 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1481 		return nfserr_inval;
1482 
1483 	return nfs_ok;
1484 }
1485 
1486 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp,
1487 					   union nfsd4_op_u *u)
1488 {
1489 	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
1490 	memset(bc, 0, sizeof(*bc));
1491 	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
1492 		return nfserr_bad_xdr;
1493 	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
1494 }
1495 
1496 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp,
1497 						union nfsd4_op_u *u)
1498 {
1499 	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
1500 	u32 use_conn_in_rdma_mode;
1501 	__be32 status;
1502 
1503 	memset(bcts, 0, sizeof(*bcts));
1504 	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
1505 	if (status)
1506 		return status;
1507 	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
1508 		return nfserr_bad_xdr;
1509 	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
1510 		return nfserr_bad_xdr;
1511 
1512 	return nfs_ok;
1513 }
1514 
1515 static __be32
1516 nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
1517 			       struct nfsd4_exchange_id *exid)
1518 {
1519 	__be32 status;
1520 
1521 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
1522 				      ARRAY_SIZE(exid->spo_must_enforce));
1523 	if (status)
1524 		return nfserr_bad_xdr;
1525 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
1526 				      ARRAY_SIZE(exid->spo_must_allow));
1527 	if (status)
1528 		return nfserr_bad_xdr;
1529 
1530 	return nfs_ok;
1531 }
1532 
1533 /*
1534  * This implementation currently does not support SP4_SSV.
1535  * This decoder simply skips over these arguments.
1536  */
1537 static noinline __be32
1538 nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
1539 			  struct nfsd4_exchange_id *exid)
1540 {
1541 	u32 count, window, num_gss_handles;
1542 	__be32 status;
1543 
1544 	/* ssp_ops */
1545 	status = nfsd4_decode_state_protect_ops(argp, exid);
1546 	if (status)
1547 		return status;
1548 
1549 	/* ssp_hash_algs<> */
1550 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1551 		return nfserr_bad_xdr;
1552 	while (count--) {
1553 		status = nfsd4_decode_ignored_string(argp, 0);
1554 		if (status)
1555 			return status;
1556 	}
1557 
1558 	/* ssp_encr_algs<> */
1559 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1560 		return nfserr_bad_xdr;
1561 	while (count--) {
1562 		status = nfsd4_decode_ignored_string(argp, 0);
1563 		if (status)
1564 			return status;
1565 	}
1566 
1567 	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
1568 		return nfserr_bad_xdr;
1569 	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
1570 		return nfserr_bad_xdr;
1571 
1572 	return nfs_ok;
1573 }
1574 
1575 static __be32
1576 nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
1577 			      struct nfsd4_exchange_id *exid)
1578 {
1579 	__be32 status;
1580 
1581 	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
1582 		return nfserr_bad_xdr;
1583 	switch (exid->spa_how) {
1584 	case SP4_NONE:
1585 		break;
1586 	case SP4_MACH_CRED:
1587 		status = nfsd4_decode_state_protect_ops(argp, exid);
1588 		if (status)
1589 			return status;
1590 		break;
1591 	case SP4_SSV:
1592 		status = nfsd4_decode_ssv_sp_parms(argp, exid);
1593 		if (status)
1594 			return status;
1595 		break;
1596 	default:
1597 		return nfserr_bad_xdr;
1598 	}
1599 
1600 	return nfs_ok;
1601 }
1602 
1603 static __be32
1604 nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
1605 			  struct nfsd4_exchange_id *exid)
1606 {
1607 	__be32 status;
1608 	u32 count;
1609 
1610 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1611 		return nfserr_bad_xdr;
1612 	switch (count) {
1613 	case 0:
1614 		break;
1615 	case 1:
1616 		/* Note that RFC 8881 places no length limit on
1617 		 * nii_domain, but this implementation permits no
1618 		 * more than NFS4_OPAQUE_LIMIT bytes */
1619 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1620 		if (status)
1621 			return status;
1622 		/* Note that RFC 8881 places no length limit on
1623 		 * nii_name, but this implementation permits no
1624 		 * more than NFS4_OPAQUE_LIMIT bytes */
1625 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1626 		if (status)
1627 			return status;
1628 		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
1629 		if (status)
1630 			return status;
1631 		break;
1632 	default:
1633 		return nfserr_bad_xdr;
1634 	}
1635 
1636 	return nfs_ok;
1637 }
1638 
1639 static __be32
1640 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1641 			 union nfsd4_op_u *u)
1642 {
1643 	struct nfsd4_exchange_id *exid = &u->exchange_id;
1644 	__be32 status;
1645 
1646 	memset(exid, 0, sizeof(*exid));
1647 	status = nfsd4_decode_verifier4(argp, &exid->verifier);
1648 	if (status)
1649 		return status;
1650 	status = nfsd4_decode_opaque(argp, &exid->clname);
1651 	if (status)
1652 		return status;
1653 	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
1654 		return nfserr_bad_xdr;
1655 	status = nfsd4_decode_state_protect4_a(argp, exid);
1656 	if (status)
1657 		return status;
1658 	return nfsd4_decode_nfs_impl_id4(argp, exid);
1659 }
1660 
1661 static __be32
1662 nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
1663 			    struct nfsd4_channel_attrs *ca)
1664 {
1665 	__be32 *p;
1666 
1667 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
1668 	if (!p)
1669 		return nfserr_bad_xdr;
1670 
1671 	/* headerpadsz is ignored */
1672 	p++;
1673 	ca->maxreq_sz = be32_to_cpup(p++);
1674 	ca->maxresp_sz = be32_to_cpup(p++);
1675 	ca->maxresp_cached = be32_to_cpup(p++);
1676 	ca->maxops = be32_to_cpup(p++);
1677 	ca->maxreqs = be32_to_cpup(p++);
1678 	ca->nr_rdma_attrs = be32_to_cpup(p);
1679 	switch (ca->nr_rdma_attrs) {
1680 	case 0:
1681 		break;
1682 	case 1:
1683 		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
1684 			return nfserr_bad_xdr;
1685 		break;
1686 	default:
1687 		return nfserr_bad_xdr;
1688 	}
1689 
1690 	return nfs_ok;
1691 }
1692 
1693 static __be32
1694 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1695 			    union nfsd4_op_u *u)
1696 {
1697 	struct nfsd4_create_session *sess = &u->create_session;
1698 	__be32 status;
1699 
1700 	memset(sess, 0, sizeof(*sess));
1701 	status = nfsd4_decode_clientid4(argp, &sess->clientid);
1702 	if (status)
1703 		return status;
1704 	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
1705 		return nfserr_bad_xdr;
1706 	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
1707 		return nfserr_bad_xdr;
1708 	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
1709 	if (status)
1710 		return status;
1711 	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
1712 	if (status)
1713 		return status;
1714 	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
1715 		return nfserr_bad_xdr;
1716 	return nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1717 }
1718 
1719 static __be32
1720 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1721 			     union nfsd4_op_u *u)
1722 {
1723 	struct nfsd4_destroy_session *destroy_session = &u->destroy_session;
1724 	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
1725 }
1726 
1727 static __be32
1728 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1729 			  union nfsd4_op_u *u)
1730 {
1731 	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
1732 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
1733 }
1734 
1735 #ifdef CONFIG_NFSD_PNFS
1736 static __be32
1737 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1738 		union nfsd4_op_u *u)
1739 {
1740 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
1741 	__be32 status;
1742 
1743 	memset(gdev, 0, sizeof(*gdev));
1744 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1745 	if (status)
1746 		return status;
1747 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1748 		return nfserr_bad_xdr;
1749 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1750 		return nfserr_bad_xdr;
1751 	if (xdr_stream_decode_uint32_array(argp->xdr,
1752 					   &gdev->gd_notify_types, 1) < 0)
1753 		return nfserr_bad_xdr;
1754 
1755 	return nfs_ok;
1756 }
1757 
1758 static __be32
1759 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1760 			  union nfsd4_op_u *u)
1761 {
1762 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
1763 	__be32 *p, status;
1764 
1765 	memset(lcp, 0, sizeof(*lcp));
1766 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1767 		return nfserr_bad_xdr;
1768 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1769 		return nfserr_bad_xdr;
1770 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1771 		return nfserr_bad_xdr;
1772 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1773 	if (status)
1774 		return status;
1775 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1776 		return nfserr_bad_xdr;
1777 	if (lcp->lc_newoffset) {
1778 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1779 			return nfserr_bad_xdr;
1780 	} else
1781 		lcp->lc_last_wr = 0;
1782 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1783 	if (!p)
1784 		return nfserr_bad_xdr;
1785 	if (xdr_item_is_present(p)) {
1786 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1787 		if (status)
1788 			return status;
1789 	} else {
1790 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1791 	}
1792 	return nfsd4_decode_layoutupdate4(argp, lcp);
1793 }
1794 
1795 static __be32
1796 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1797 		union nfsd4_op_u *u)
1798 {
1799 	struct nfsd4_layoutget *lgp = &u->layoutget;
1800 	__be32 status;
1801 
1802 	memset(lgp, 0, sizeof(*lgp));
1803 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1804 		return nfserr_bad_xdr;
1805 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1806 		return nfserr_bad_xdr;
1807 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1808 		return nfserr_bad_xdr;
1809 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1810 		return nfserr_bad_xdr;
1811 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1812 		return nfserr_bad_xdr;
1813 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1814 		return nfserr_bad_xdr;
1815 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1816 	if (status)
1817 		return status;
1818 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1819 		return nfserr_bad_xdr;
1820 
1821 	return nfs_ok;
1822 }
1823 
1824 static __be32
1825 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1826 		union nfsd4_op_u *u)
1827 {
1828 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
1829 	memset(lrp, 0, sizeof(*lrp));
1830 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1831 		return nfserr_bad_xdr;
1832 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1833 		return nfserr_bad_xdr;
1834 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1835 		return nfserr_bad_xdr;
1836 	return nfsd4_decode_layoutreturn4(argp, lrp);
1837 }
1838 #endif /* CONFIG_NFSD_PNFS */
1839 
1840 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1841 					   union nfsd4_op_u *u)
1842 {
1843 	struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name;
1844 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1845 		return nfserr_bad_xdr;
1846 
1847 	sin->sin_exp = NULL;
1848 	return nfs_ok;
1849 }
1850 
1851 static __be32
1852 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1853 		      union nfsd4_op_u *u)
1854 {
1855 	struct nfsd4_sequence *seq = &u->sequence;
1856 	__be32 *p, status;
1857 
1858 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1859 	if (status)
1860 		return status;
1861 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1862 	if (!p)
1863 		return nfserr_bad_xdr;
1864 	seq->seqid = be32_to_cpup(p++);
1865 	seq->slotid = be32_to_cpup(p++);
1866 	seq->maxslots = be32_to_cpup(p++);
1867 	seq->cachethis = be32_to_cpup(p);
1868 
1869 	seq->status_flags = 0;
1870 	return nfs_ok;
1871 }
1872 
1873 static __be32
1874 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp,
1875 			  union nfsd4_op_u *u)
1876 {
1877 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
1878 	struct nfsd4_test_stateid_id *stateid;
1879 	__be32 status;
1880 	u32 i;
1881 
1882 	memset(test_stateid, 0, sizeof(*test_stateid));
1883 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1884 		return nfserr_bad_xdr;
1885 
1886 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1887 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1888 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1889 		if (!stateid)
1890 			return nfserr_jukebox;
1891 		INIT_LIST_HEAD(&stateid->ts_id_list);
1892 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1893 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1894 		if (status)
1895 			return status;
1896 	}
1897 
1898 	return nfs_ok;
1899 }
1900 
1901 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1902 					    union nfsd4_op_u *u)
1903 {
1904 	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
1905 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1906 }
1907 
1908 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1909 					    union nfsd4_op_u *u)
1910 {
1911 	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
1912 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1913 		return nfserr_bad_xdr;
1914 	return nfs_ok;
1915 }
1916 
1917 static __be32
1918 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1919 		       union nfsd4_op_u *u)
1920 {
1921 	struct nfsd4_fallocate *fallocate = &u->allocate;
1922 	__be32 status;
1923 
1924 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1925 	if (status)
1926 		return status;
1927 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1928 		return nfserr_bad_xdr;
1929 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1930 		return nfserr_bad_xdr;
1931 
1932 	return nfs_ok;
1933 }
1934 
1935 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1936 				      struct nl4_server *ns)
1937 {
1938 	struct nfs42_netaddr *naddr;
1939 	__be32 *p;
1940 
1941 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1942 		return nfserr_bad_xdr;
1943 
1944 	/* currently support for 1 inter-server source server */
1945 	switch (ns->nl4_type) {
1946 	case NL4_NETADDR:
1947 		naddr = &ns->u.nl4_addr;
1948 
1949 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1950 			return nfserr_bad_xdr;
1951 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1952 			return nfserr_bad_xdr;
1953 
1954 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1955 		if (!p)
1956 			return nfserr_bad_xdr;
1957 		memcpy(naddr->netid, p, naddr->netid_len);
1958 
1959 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1960 			return nfserr_bad_xdr;
1961 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1962 			return nfserr_bad_xdr;
1963 
1964 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1965 		if (!p)
1966 			return nfserr_bad_xdr;
1967 		memcpy(naddr->addr, p, naddr->addr_len);
1968 		break;
1969 	default:
1970 		return nfserr_bad_xdr;
1971 	}
1972 
1973 	return nfs_ok;
1974 }
1975 
1976 static __be32
1977 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1978 {
1979 	struct nfsd4_copy *copy = &u->copy;
1980 	u32 consecutive, i, count, sync;
1981 	struct nl4_server *ns_dummy;
1982 	__be32 status;
1983 
1984 	memset(copy, 0, sizeof(*copy));
1985 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
1986 	if (status)
1987 		return status;
1988 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
1989 	if (status)
1990 		return status;
1991 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
1992 		return nfserr_bad_xdr;
1993 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
1994 		return nfserr_bad_xdr;
1995 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
1996 		return nfserr_bad_xdr;
1997 	/* ca_consecutive: we always do consecutive copies */
1998 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
1999 		return nfserr_bad_xdr;
2000 	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
2001 		return nfserr_bad_xdr;
2002 	nfsd4_copy_set_sync(copy, sync);
2003 
2004 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
2005 		return nfserr_bad_xdr;
2006 	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
2007 	if (copy->cp_src == NULL)
2008 		return nfserr_jukebox;
2009 	if (count == 0) { /* intra-server copy */
2010 		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
2011 		return nfs_ok;
2012 	}
2013 
2014 	/* decode all the supplied server addresses but use only the first */
2015 	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
2016 	if (status)
2017 		return status;
2018 
2019 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
2020 	if (ns_dummy == NULL)
2021 		return nfserr_jukebox;
2022 	for (i = 0; i < count - 1; i++) {
2023 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
2024 		if (status) {
2025 			kfree(ns_dummy);
2026 			return status;
2027 		}
2028 	}
2029 	kfree(ns_dummy);
2030 
2031 	return nfs_ok;
2032 }
2033 
2034 static __be32
2035 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
2036 			 union nfsd4_op_u *u)
2037 {
2038 	struct nfsd4_copy_notify *cn = &u->copy_notify;
2039 	__be32 status;
2040 
2041 	memset(cn, 0, sizeof(*cn));
2042 	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
2043 	if (cn->cpn_src == NULL)
2044 		return nfserr_jukebox;
2045 	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
2046 	if (cn->cpn_dst == NULL)
2047 		return nfserr_jukebox;
2048 
2049 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
2050 	if (status)
2051 		return status;
2052 	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
2053 }
2054 
2055 static __be32
2056 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
2057 			    union nfsd4_op_u *u)
2058 {
2059 	struct nfsd4_offload_status *os = &u->offload_status;
2060 	os->count = 0;
2061 	os->status = 0;
2062 	return nfsd4_decode_stateid4(argp, &os->stateid);
2063 }
2064 
2065 static __be32
2066 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2067 {
2068 	struct nfsd4_seek *seek = &u->seek;
2069 	__be32 status;
2070 
2071 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
2072 	if (status)
2073 		return status;
2074 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
2075 		return nfserr_bad_xdr;
2076 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
2077 		return nfserr_bad_xdr;
2078 
2079 	seek->seek_eof = 0;
2080 	seek->seek_pos = 0;
2081 	return nfs_ok;
2082 }
2083 
2084 static __be32
2085 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2086 {
2087 	struct nfsd4_clone *clone = &u->clone;
2088 	__be32 status;
2089 
2090 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
2091 	if (status)
2092 		return status;
2093 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
2094 	if (status)
2095 		return status;
2096 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
2097 		return nfserr_bad_xdr;
2098 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
2099 		return nfserr_bad_xdr;
2100 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
2101 		return nfserr_bad_xdr;
2102 
2103 	return nfs_ok;
2104 }
2105 
2106 /*
2107  * XDR data that is more than PAGE_SIZE in size is normally part of a
2108  * read or write. However, the size of extended attributes is limited
2109  * by the maximum request size, and then further limited by the underlying
2110  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2111  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2112  * and we're not dealing with contiguous pages, we need to do some copying.
2113  */
2114 
2115 /*
2116  * Decode data into buffer.
2117  */
2118 static __be32
2119 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2120 		       char **bufp, u32 buflen)
2121 {
2122 	struct page **pages = xdr->pages;
2123 	struct kvec *head = xdr->head;
2124 	char *tmp, *dp;
2125 	u32 len;
2126 
2127 	if (buflen <= head->iov_len) {
2128 		/*
2129 		 * We're in luck, the head has enough space. Just return
2130 		 * the head, no need for copying.
2131 		 */
2132 		*bufp = head->iov_base;
2133 		return 0;
2134 	}
2135 
2136 	tmp = svcxdr_tmpalloc(argp, buflen);
2137 	if (tmp == NULL)
2138 		return nfserr_jukebox;
2139 
2140 	dp = tmp;
2141 	memcpy(dp, head->iov_base, head->iov_len);
2142 	buflen -= head->iov_len;
2143 	dp += head->iov_len;
2144 
2145 	while (buflen > 0) {
2146 		len = min_t(u32, buflen, PAGE_SIZE);
2147 		memcpy(dp, page_address(*pages), len);
2148 
2149 		buflen -= len;
2150 		dp += len;
2151 		pages++;
2152 	}
2153 
2154 	*bufp = tmp;
2155 	return 0;
2156 }
2157 
2158 /*
2159  * Get a user extended attribute name from the XDR buffer.
2160  * It will not have the "user." prefix, so prepend it.
2161  * Lastly, check for nul characters in the name.
2162  */
2163 static __be32
2164 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2165 {
2166 	char *name, *sp, *dp;
2167 	u32 namelen, cnt;
2168 	__be32 *p;
2169 
2170 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2171 		return nfserr_bad_xdr;
2172 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2173 		return nfserr_nametoolong;
2174 	if (namelen == 0)
2175 		return nfserr_bad_xdr;
2176 	p = xdr_inline_decode(argp->xdr, namelen);
2177 	if (!p)
2178 		return nfserr_bad_xdr;
2179 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2180 	if (!name)
2181 		return nfserr_jukebox;
2182 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2183 
2184 	/*
2185 	 * Copy the extended attribute name over while checking for 0
2186 	 * characters.
2187 	 */
2188 	sp = (char *)p;
2189 	dp = name + XATTR_USER_PREFIX_LEN;
2190 	cnt = namelen;
2191 
2192 	while (cnt-- > 0) {
2193 		if (*sp == '\0')
2194 			return nfserr_bad_xdr;
2195 		*dp++ = *sp++;
2196 	}
2197 	*dp = '\0';
2198 
2199 	*namep = name;
2200 
2201 	return nfs_ok;
2202 }
2203 
2204 /*
2205  * A GETXATTR op request comes without a length specifier. We just set the
2206  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2207  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2208  * check it against getxa_len, and allocate + return the value.
2209  */
2210 static __be32
2211 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2212 		      union nfsd4_op_u *u)
2213 {
2214 	struct nfsd4_getxattr *getxattr = &u->getxattr;
2215 	__be32 status;
2216 	u32 maxcount;
2217 
2218 	memset(getxattr, 0, sizeof(*getxattr));
2219 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2220 	if (status)
2221 		return status;
2222 
2223 	maxcount = svc_max_payload(argp->rqstp);
2224 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2225 
2226 	getxattr->getxa_len = maxcount;
2227 	return nfs_ok;
2228 }
2229 
2230 static __be32
2231 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2232 		      union nfsd4_op_u *u)
2233 {
2234 	struct nfsd4_setxattr *setxattr = &u->setxattr;
2235 	u32 flags, maxcount, size;
2236 	__be32 status;
2237 
2238 	memset(setxattr, 0, sizeof(*setxattr));
2239 
2240 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2241 		return nfserr_bad_xdr;
2242 
2243 	if (flags > SETXATTR4_REPLACE)
2244 		return nfserr_inval;
2245 	setxattr->setxa_flags = flags;
2246 
2247 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2248 	if (status)
2249 		return status;
2250 
2251 	maxcount = svc_max_payload(argp->rqstp);
2252 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2253 
2254 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2255 		return nfserr_bad_xdr;
2256 	if (size > maxcount)
2257 		return nfserr_xattr2big;
2258 
2259 	setxattr->setxa_len = size;
2260 	if (size > 0) {
2261 		struct xdr_buf payload;
2262 
2263 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2264 			return nfserr_bad_xdr;
2265 		status = nfsd4_vbuf_from_vector(argp, &payload,
2266 						&setxattr->setxa_buf, size);
2267 	}
2268 
2269 	return nfs_ok;
2270 }
2271 
2272 static __be32
2273 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2274 			union nfsd4_op_u *u)
2275 {
2276 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
2277 	u32 maxcount;
2278 
2279 	memset(listxattrs, 0, sizeof(*listxattrs));
2280 
2281 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2282 		return nfserr_bad_xdr;
2283 
2284 	/*
2285 	 * If the cookie  is too large to have even one user.x attribute
2286 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2287 	 */
2288 	if (listxattrs->lsxa_cookie >=
2289 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2290 		return nfserr_badcookie;
2291 
2292 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2293 		return nfserr_bad_xdr;
2294 	if (maxcount < 8)
2295 		/* Always need at least 2 words (length and one character) */
2296 		return nfserr_inval;
2297 
2298 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2299 	listxattrs->lsxa_maxcount = maxcount;
2300 
2301 	return nfs_ok;
2302 }
2303 
2304 static __be32
2305 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2306 			 union nfsd4_op_u *u)
2307 {
2308 	struct nfsd4_removexattr *removexattr = &u->removexattr;
2309 	memset(removexattr, 0, sizeof(*removexattr));
2310 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2311 }
2312 
2313 static __be32
2314 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2315 {
2316 	return nfs_ok;
2317 }
2318 
2319 static __be32
2320 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2321 {
2322 	return nfserr_notsupp;
2323 }
2324 
2325 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u);
2326 
2327 static const nfsd4_dec nfsd4_dec_ops[] = {
2328 	[OP_ACCESS]		= nfsd4_decode_access,
2329 	[OP_CLOSE]		= nfsd4_decode_close,
2330 	[OP_COMMIT]		= nfsd4_decode_commit,
2331 	[OP_CREATE]		= nfsd4_decode_create,
2332 	[OP_DELEGPURGE]		= nfsd4_decode_notsupp,
2333 	[OP_DELEGRETURN]	= nfsd4_decode_delegreturn,
2334 	[OP_GETATTR]		= nfsd4_decode_getattr,
2335 	[OP_GETFH]		= nfsd4_decode_noop,
2336 	[OP_LINK]		= nfsd4_decode_link,
2337 	[OP_LOCK]		= nfsd4_decode_lock,
2338 	[OP_LOCKT]		= nfsd4_decode_lockt,
2339 	[OP_LOCKU]		= nfsd4_decode_locku,
2340 	[OP_LOOKUP]		= nfsd4_decode_lookup,
2341 	[OP_LOOKUPP]		= nfsd4_decode_noop,
2342 	[OP_NVERIFY]		= nfsd4_decode_verify,
2343 	[OP_OPEN]		= nfsd4_decode_open,
2344 	[OP_OPENATTR]		= nfsd4_decode_notsupp,
2345 	[OP_OPEN_CONFIRM]	= nfsd4_decode_open_confirm,
2346 	[OP_OPEN_DOWNGRADE]	= nfsd4_decode_open_downgrade,
2347 	[OP_PUTFH]		= nfsd4_decode_putfh,
2348 	[OP_PUTPUBFH]		= nfsd4_decode_putpubfh,
2349 	[OP_PUTROOTFH]		= nfsd4_decode_noop,
2350 	[OP_READ]		= nfsd4_decode_read,
2351 	[OP_READDIR]		= nfsd4_decode_readdir,
2352 	[OP_READLINK]		= nfsd4_decode_noop,
2353 	[OP_REMOVE]		= nfsd4_decode_remove,
2354 	[OP_RENAME]		= nfsd4_decode_rename,
2355 	[OP_RENEW]		= nfsd4_decode_renew,
2356 	[OP_RESTOREFH]		= nfsd4_decode_noop,
2357 	[OP_SAVEFH]		= nfsd4_decode_noop,
2358 	[OP_SECINFO]		= nfsd4_decode_secinfo,
2359 	[OP_SETATTR]		= nfsd4_decode_setattr,
2360 	[OP_SETCLIENTID]	= nfsd4_decode_setclientid,
2361 	[OP_SETCLIENTID_CONFIRM] = nfsd4_decode_setclientid_confirm,
2362 	[OP_VERIFY]		= nfsd4_decode_verify,
2363 	[OP_WRITE]		= nfsd4_decode_write,
2364 	[OP_RELEASE_LOCKOWNER]	= nfsd4_decode_release_lockowner,
2365 
2366 	/* new operations for NFSv4.1 */
2367 	[OP_BACKCHANNEL_CTL]	= nfsd4_decode_backchannel_ctl,
2368 	[OP_BIND_CONN_TO_SESSION] = nfsd4_decode_bind_conn_to_session,
2369 	[OP_EXCHANGE_ID]	= nfsd4_decode_exchange_id,
2370 	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
2371 	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
2372 	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
2373 	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_notsupp,
2374 #ifdef CONFIG_NFSD_PNFS
2375 	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
2376 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2377 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_layoutcommit,
2378 	[OP_LAYOUTGET]		= nfsd4_decode_layoutget,
2379 	[OP_LAYOUTRETURN]	= nfsd4_decode_layoutreturn,
2380 #else
2381 	[OP_GETDEVICEINFO]	= nfsd4_decode_notsupp,
2382 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2383 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_notsupp,
2384 	[OP_LAYOUTGET]		= nfsd4_decode_notsupp,
2385 	[OP_LAYOUTRETURN]	= nfsd4_decode_notsupp,
2386 #endif
2387 	[OP_SECINFO_NO_NAME]	= nfsd4_decode_secinfo_no_name,
2388 	[OP_SEQUENCE]		= nfsd4_decode_sequence,
2389 	[OP_SET_SSV]		= nfsd4_decode_notsupp,
2390 	[OP_TEST_STATEID]	= nfsd4_decode_test_stateid,
2391 	[OP_WANT_DELEGATION]	= nfsd4_decode_notsupp,
2392 	[OP_DESTROY_CLIENTID]	= nfsd4_decode_destroy_clientid,
2393 	[OP_RECLAIM_COMPLETE]	= nfsd4_decode_reclaim_complete,
2394 
2395 	/* new operations for NFSv4.2 */
2396 	[OP_ALLOCATE]		= nfsd4_decode_fallocate,
2397 	[OP_COPY]		= nfsd4_decode_copy,
2398 	[OP_COPY_NOTIFY]	= nfsd4_decode_copy_notify,
2399 	[OP_DEALLOCATE]		= nfsd4_decode_fallocate,
2400 	[OP_IO_ADVISE]		= nfsd4_decode_notsupp,
2401 	[OP_LAYOUTERROR]	= nfsd4_decode_notsupp,
2402 	[OP_LAYOUTSTATS]	= nfsd4_decode_notsupp,
2403 	[OP_OFFLOAD_CANCEL]	= nfsd4_decode_offload_status,
2404 	[OP_OFFLOAD_STATUS]	= nfsd4_decode_offload_status,
2405 	[OP_READ_PLUS]		= nfsd4_decode_read,
2406 	[OP_SEEK]		= nfsd4_decode_seek,
2407 	[OP_WRITE_SAME]		= nfsd4_decode_notsupp,
2408 	[OP_CLONE]		= nfsd4_decode_clone,
2409 	/* RFC 8276 extended atributes operations */
2410 	[OP_GETXATTR]		= nfsd4_decode_getxattr,
2411 	[OP_SETXATTR]		= nfsd4_decode_setxattr,
2412 	[OP_LISTXATTRS]		= nfsd4_decode_listxattrs,
2413 	[OP_REMOVEXATTR]	= nfsd4_decode_removexattr,
2414 };
2415 
2416 static inline bool
2417 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2418 {
2419 	if (op->opnum < FIRST_NFS4_OP)
2420 		return false;
2421 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2422 		return false;
2423 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2424 		return false;
2425 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2426 		return false;
2427 	return true;
2428 }
2429 
2430 static bool
2431 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2432 {
2433 	struct nfsd4_op *op;
2434 	bool cachethis = false;
2435 	int auth_slack= argp->rqstp->rq_auth_slack;
2436 	int max_reply = auth_slack + 8; /* opcnt, status */
2437 	int readcount = 0;
2438 	int readbytes = 0;
2439 	__be32 *p;
2440 	int i;
2441 
2442 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2443 		return false;
2444 	max_reply += XDR_UNIT;
2445 	argp->tag = NULL;
2446 	if (unlikely(argp->taglen)) {
2447 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2448 			return false;
2449 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2450 		if (!p)
2451 			return false;
2452 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2453 		if (!argp->tag)
2454 			return false;
2455 		max_reply += xdr_align_size(argp->taglen);
2456 	}
2457 
2458 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2459 		return false;
2460 	if (xdr_stream_decode_u32(argp->xdr, &argp->client_opcnt) < 0)
2461 		return false;
2462 	argp->opcnt = min_t(u32, argp->client_opcnt,
2463 			    NFSD_MAX_OPS_PER_COMPOUND);
2464 
2465 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2466 		argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops));
2467 		if (!argp->ops) {
2468 			argp->ops = argp->iops;
2469 			return false;
2470 		}
2471 	}
2472 
2473 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2474 		argp->opcnt = 0;
2475 
2476 	for (i = 0; i < argp->opcnt; i++) {
2477 		op = &argp->ops[i];
2478 		op->replay = NULL;
2479 		op->opdesc = NULL;
2480 
2481 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2482 			return false;
2483 		if (nfsd4_opnum_in_range(argp, op)) {
2484 			op->opdesc = OPDESC(op);
2485 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2486 			if (op->status != nfs_ok)
2487 				trace_nfsd_compound_decode_err(argp->rqstp,
2488 							       argp->opcnt, i,
2489 							       op->opnum,
2490 							       op->status);
2491 		} else {
2492 			op->opnum = OP_ILLEGAL;
2493 			op->status = nfserr_op_illegal;
2494 		}
2495 
2496 		/*
2497 		 * We'll try to cache the result in the DRC if any one
2498 		 * op in the compound wants to be cached:
2499 		 */
2500 		cachethis |= nfsd4_cache_this_op(op);
2501 
2502 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2503 			readcount++;
2504 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2505 		} else
2506 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2507 		/*
2508 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2509 		 * (Special case because it will just skip encoding this
2510 		 * if it runs out of xdr buffer space, and it is the only
2511 		 * operation that behaves this way.)
2512 		 */
2513 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2514 			max_reply += NFS4_OPAQUE_LIMIT;
2515 
2516 		if (op->status) {
2517 			argp->opcnt = i+1;
2518 			break;
2519 		}
2520 	}
2521 	/* Sessions make the DRC unnecessary: */
2522 	if (argp->minorversion)
2523 		cachethis = false;
2524 	svc_reserve(argp->rqstp, max_reply + readbytes);
2525 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2526 
2527 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2528 		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
2529 
2530 	return true;
2531 }
2532 
2533 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
2534 			     struct svc_export *exp)
2535 {
2536 	if (exp->ex_flags & NFSEXP_V4ROOT) {
2537 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
2538 		*p++ = 0;
2539 	} else
2540 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2541 	return p;
2542 }
2543 
2544 static __be32 nfsd4_encode_nfstime4(struct xdr_stream *xdr,
2545 				    struct timespec64 *tv)
2546 {
2547 	__be32 *p;
2548 
2549 	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
2550 	if (!p)
2551 		return nfserr_resource;
2552 
2553 	p = xdr_encode_hyper(p, (s64)tv->tv_sec);
2554 	*p = cpu_to_be32(tv->tv_nsec);
2555 	return nfs_ok;
2556 }
2557 
2558 /*
2559  * ctime (in NFSv4, time_metadata) is not writeable, and the client
2560  * doesn't really care what resolution could theoretically be stored by
2561  * the filesystem.
2562  *
2563  * The client cares how close together changes can be while still
2564  * guaranteeing ctime changes.  For most filesystems (which have
2565  * timestamps with nanosecond fields) that is limited by the resolution
2566  * of the time returned from current_time() (which I'm assuming to be
2567  * 1/HZ).
2568  */
2569 static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
2570 {
2571 	struct timespec64 ts;
2572 	u32 ns;
2573 
2574 	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
2575 	ts = ns_to_timespec64(ns);
2576 
2577 	p = xdr_encode_hyper(p, ts.tv_sec);
2578 	*p++ = cpu_to_be32(ts.tv_nsec);
2579 
2580 	return p;
2581 }
2582 
2583 static __be32
2584 nfsd4_encode_change_info4(struct xdr_stream *xdr, struct nfsd4_change_info *c)
2585 {
2586 	if (xdr_stream_encode_bool(xdr, c->atomic) < 0)
2587 		return nfserr_resource;
2588 	if (xdr_stream_encode_u64(xdr, c->before_change) < 0)
2589 		return nfserr_resource;
2590 	if (xdr_stream_encode_u64(xdr, c->after_change) < 0)
2591 		return nfserr_resource;
2592 	return nfs_ok;
2593 }
2594 
2595 /* Encode as an array of strings the string given with components
2596  * separated @sep, escaped with esc_enter and esc_exit.
2597  */
2598 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2599 					  char *components, char esc_enter,
2600 					  char esc_exit)
2601 {
2602 	__be32 *p;
2603 	__be32 pathlen;
2604 	int pathlen_offset;
2605 	int strlen, count=0;
2606 	char *str, *end, *next;
2607 
2608 	dprintk("nfsd4_encode_components(%s)\n", components);
2609 
2610 	pathlen_offset = xdr->buf->len;
2611 	p = xdr_reserve_space(xdr, 4);
2612 	if (!p)
2613 		return nfserr_resource;
2614 	p++; /* We will fill this in with @count later */
2615 
2616 	end = str = components;
2617 	while (*end) {
2618 		bool found_esc = false;
2619 
2620 		/* try to parse as esc_start, ..., esc_end, sep */
2621 		if (*str == esc_enter) {
2622 			for (; *end && (*end != esc_exit); end++)
2623 				/* find esc_exit or end of string */;
2624 			next = end + 1;
2625 			if (*end && (!*next || *next == sep)) {
2626 				str++;
2627 				found_esc = true;
2628 			}
2629 		}
2630 
2631 		if (!found_esc)
2632 			for (; *end && (*end != sep); end++)
2633 				/* find sep or end of string */;
2634 
2635 		strlen = end - str;
2636 		if (strlen) {
2637 			p = xdr_reserve_space(xdr, strlen + 4);
2638 			if (!p)
2639 				return nfserr_resource;
2640 			p = xdr_encode_opaque(p, str, strlen);
2641 			count++;
2642 		}
2643 		else
2644 			end++;
2645 		if (found_esc)
2646 			end = next;
2647 
2648 		str = end;
2649 	}
2650 	pathlen = htonl(count);
2651 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2652 	return 0;
2653 }
2654 
2655 /* Encode as an array of strings the string given with components
2656  * separated @sep.
2657  */
2658 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2659 				      char *components)
2660 {
2661 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2662 }
2663 
2664 /*
2665  * encode a location element of a fs_locations structure
2666  */
2667 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2668 					struct nfsd4_fs_location *location)
2669 {
2670 	__be32 status;
2671 
2672 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2673 						'[', ']');
2674 	if (status)
2675 		return status;
2676 	status = nfsd4_encode_components(xdr, '/', location->path);
2677 	if (status)
2678 		return status;
2679 	return 0;
2680 }
2681 
2682 /*
2683  * Encode a path in RFC3530 'pathname4' format
2684  */
2685 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2686 				const struct path *root,
2687 				const struct path *path)
2688 {
2689 	struct path cur = *path;
2690 	__be32 *p;
2691 	struct dentry **components = NULL;
2692 	unsigned int ncomponents = 0;
2693 	__be32 err = nfserr_jukebox;
2694 
2695 	dprintk("nfsd4_encode_components(");
2696 
2697 	path_get(&cur);
2698 	/* First walk the path up to the nfsd root, and store the
2699 	 * dentries/path components in an array.
2700 	 */
2701 	for (;;) {
2702 		if (path_equal(&cur, root))
2703 			break;
2704 		if (cur.dentry == cur.mnt->mnt_root) {
2705 			if (follow_up(&cur))
2706 				continue;
2707 			goto out_free;
2708 		}
2709 		if ((ncomponents & 15) == 0) {
2710 			struct dentry **new;
2711 			new = krealloc(components,
2712 					sizeof(*new) * (ncomponents + 16),
2713 					GFP_KERNEL);
2714 			if (!new)
2715 				goto out_free;
2716 			components = new;
2717 		}
2718 		components[ncomponents++] = cur.dentry;
2719 		cur.dentry = dget_parent(cur.dentry);
2720 	}
2721 	err = nfserr_resource;
2722 	p = xdr_reserve_space(xdr, 4);
2723 	if (!p)
2724 		goto out_free;
2725 	*p++ = cpu_to_be32(ncomponents);
2726 
2727 	while (ncomponents) {
2728 		struct dentry *dentry = components[ncomponents - 1];
2729 		unsigned int len;
2730 
2731 		spin_lock(&dentry->d_lock);
2732 		len = dentry->d_name.len;
2733 		p = xdr_reserve_space(xdr, len + 4);
2734 		if (!p) {
2735 			spin_unlock(&dentry->d_lock);
2736 			goto out_free;
2737 		}
2738 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2739 		dprintk("/%pd", dentry);
2740 		spin_unlock(&dentry->d_lock);
2741 		dput(dentry);
2742 		ncomponents--;
2743 	}
2744 
2745 	err = 0;
2746 out_free:
2747 	dprintk(")\n");
2748 	while (ncomponents)
2749 		dput(components[--ncomponents]);
2750 	kfree(components);
2751 	path_put(&cur);
2752 	return err;
2753 }
2754 
2755 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2756 			struct svc_rqst *rqstp, const struct path *path)
2757 {
2758 	struct svc_export *exp_ps;
2759 	__be32 res;
2760 
2761 	exp_ps = rqst_find_fsidzero_export(rqstp);
2762 	if (IS_ERR(exp_ps))
2763 		return nfserrno(PTR_ERR(exp_ps));
2764 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2765 	exp_put(exp_ps);
2766 	return res;
2767 }
2768 
2769 /*
2770  *  encode a fs_locations structure
2771  */
2772 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2773 			struct svc_rqst *rqstp, struct svc_export *exp)
2774 {
2775 	__be32 status;
2776 	int i;
2777 	__be32 *p;
2778 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2779 
2780 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2781 	if (status)
2782 		return status;
2783 	p = xdr_reserve_space(xdr, 4);
2784 	if (!p)
2785 		return nfserr_resource;
2786 	*p++ = cpu_to_be32(fslocs->locations_count);
2787 	for (i=0; i<fslocs->locations_count; i++) {
2788 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2789 		if (status)
2790 			return status;
2791 	}
2792 	return 0;
2793 }
2794 
2795 static u32 nfs4_file_type(umode_t mode)
2796 {
2797 	switch (mode & S_IFMT) {
2798 	case S_IFIFO:	return NF4FIFO;
2799 	case S_IFCHR:	return NF4CHR;
2800 	case S_IFDIR:	return NF4DIR;
2801 	case S_IFBLK:	return NF4BLK;
2802 	case S_IFLNK:	return NF4LNK;
2803 	case S_IFREG:	return NF4REG;
2804 	case S_IFSOCK:	return NF4SOCK;
2805 	default:	return NF4BAD;
2806 	}
2807 }
2808 
2809 static inline __be32
2810 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2811 		     struct nfs4_ace *ace)
2812 {
2813 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2814 		return nfs4_acl_write_who(xdr, ace->whotype);
2815 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2816 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2817 	else
2818 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2819 }
2820 
2821 static inline __be32
2822 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2823 {
2824 	__be32		*p;
2825 	unsigned long	i = hweight_long(layout_types);
2826 
2827 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2828 	if (!p)
2829 		return nfserr_resource;
2830 
2831 	*p++ = cpu_to_be32(i);
2832 
2833 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2834 		if (layout_types & (1 << i))
2835 			*p++ = cpu_to_be32(i);
2836 
2837 	return 0;
2838 }
2839 
2840 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2841 			      FATTR4_WORD0_RDATTR_ERROR)
2842 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2843 #define WORD2_ABSENT_FS_ATTRS 0
2844 
2845 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2846 static inline __be32
2847 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2848 			    void *context, int len)
2849 {
2850 	__be32 *p;
2851 
2852 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2853 	if (!p)
2854 		return nfserr_resource;
2855 
2856 	/*
2857 	 * For now we use a 0 here to indicate the null translation; in
2858 	 * the future we may place a call to translation code here.
2859 	 */
2860 	*p++ = cpu_to_be32(0); /* lfs */
2861 	*p++ = cpu_to_be32(0); /* pi */
2862 	p = xdr_encode_opaque(p, context, len);
2863 	return 0;
2864 }
2865 #else
2866 static inline __be32
2867 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2868 			    void *context, int len)
2869 { return 0; }
2870 #endif
2871 
2872 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2873 {
2874 	/* As per referral draft:  */
2875 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2876 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2877 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2878 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2879 			*rdattr_err = NFSERR_MOVED;
2880 		else
2881 			return nfserr_moved;
2882 	}
2883 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2884 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2885 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2886 	return 0;
2887 }
2888 
2889 
2890 static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
2891 {
2892 	struct path path = exp->ex_path;
2893 	struct kstat stat;
2894 	int err;
2895 
2896 	path_get(&path);
2897 	while (follow_up(&path)) {
2898 		if (path.dentry != path.mnt->mnt_root)
2899 			break;
2900 	}
2901 	err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
2902 	path_put(&path);
2903 	if (!err)
2904 		*pino = stat.ino;
2905 	return err;
2906 }
2907 
2908 static __be32
2909 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2910 {
2911 	__be32 *p;
2912 
2913 	if (bmval2) {
2914 		p = xdr_reserve_space(xdr, 16);
2915 		if (!p)
2916 			goto out_resource;
2917 		*p++ = cpu_to_be32(3);
2918 		*p++ = cpu_to_be32(bmval0);
2919 		*p++ = cpu_to_be32(bmval1);
2920 		*p++ = cpu_to_be32(bmval2);
2921 	} else if (bmval1) {
2922 		p = xdr_reserve_space(xdr, 12);
2923 		if (!p)
2924 			goto out_resource;
2925 		*p++ = cpu_to_be32(2);
2926 		*p++ = cpu_to_be32(bmval0);
2927 		*p++ = cpu_to_be32(bmval1);
2928 	} else {
2929 		p = xdr_reserve_space(xdr, 8);
2930 		if (!p)
2931 			goto out_resource;
2932 		*p++ = cpu_to_be32(1);
2933 		*p++ = cpu_to_be32(bmval0);
2934 	}
2935 
2936 	return 0;
2937 out_resource:
2938 	return nfserr_resource;
2939 }
2940 
2941 /*
2942  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2943  * ourselves.
2944  */
2945 static __be32
2946 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2947 		struct svc_export *exp,
2948 		struct dentry *dentry, u32 *bmval,
2949 		struct svc_rqst *rqstp, int ignore_crossmnt)
2950 {
2951 	u32 bmval0 = bmval[0];
2952 	u32 bmval1 = bmval[1];
2953 	u32 bmval2 = bmval[2];
2954 	struct kstat stat;
2955 	struct svc_fh *tempfh = NULL;
2956 	struct kstatfs statfs;
2957 	__be32 *p, *attrlen_p;
2958 	int starting_len = xdr->buf->len;
2959 	int attrlen_offset;
2960 	u32 dummy;
2961 	u64 dummy64;
2962 	u32 rdattr_err = 0;
2963 	__be32 status;
2964 	int err;
2965 	struct nfs4_acl *acl = NULL;
2966 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2967 	void *context = NULL;
2968 	int contextlen;
2969 #endif
2970 	bool contextsupport = false;
2971 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2972 	u32 minorversion = resp->cstate.minorversion;
2973 	struct path path = {
2974 		.mnt	= exp->ex_path.mnt,
2975 		.dentry	= dentry,
2976 	};
2977 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2978 
2979 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2980 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2981 
2982 	if (exp->ex_fslocs.migrated) {
2983 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2984 		if (status)
2985 			goto out;
2986 	}
2987 	if (bmval0 & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {
2988 		status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry));
2989 		if (status)
2990 			goto out;
2991 	}
2992 
2993 	err = vfs_getattr(&path, &stat,
2994 			  STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
2995 			  AT_STATX_SYNC_AS_STAT);
2996 	if (err)
2997 		goto out_nfserr;
2998 	if (!(stat.result_mask & STATX_BTIME))
2999 		/* underlying FS does not offer btime so we can't share it */
3000 		bmval1 &= ~FATTR4_WORD1_TIME_CREATE;
3001 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
3002 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
3003 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
3004 		       FATTR4_WORD1_SPACE_TOTAL))) {
3005 		err = vfs_statfs(&path, &statfs);
3006 		if (err)
3007 			goto out_nfserr;
3008 	}
3009 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
3010 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
3011 		status = nfserr_jukebox;
3012 		if (!tempfh)
3013 			goto out;
3014 		fh_init(tempfh, NFS4_FHSIZE);
3015 		status = fh_compose(tempfh, exp, dentry, NULL);
3016 		if (status)
3017 			goto out;
3018 		fhp = tempfh;
3019 	}
3020 	if (bmval0 & FATTR4_WORD0_ACL) {
3021 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
3022 		if (err == -EOPNOTSUPP)
3023 			bmval0 &= ~FATTR4_WORD0_ACL;
3024 		else if (err == -EINVAL) {
3025 			status = nfserr_attrnotsupp;
3026 			goto out;
3027 		} else if (err != 0)
3028 			goto out_nfserr;
3029 	}
3030 
3031 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3032 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
3033 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
3034 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
3035 			err = security_inode_getsecctx(d_inode(dentry),
3036 						&context, &contextlen);
3037 		else
3038 			err = -EOPNOTSUPP;
3039 		contextsupport = (err == 0);
3040 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
3041 			if (err == -EOPNOTSUPP)
3042 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
3043 			else if (err)
3044 				goto out_nfserr;
3045 		}
3046 	}
3047 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3048 
3049 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
3050 	if (status)
3051 		goto out;
3052 
3053 	attrlen_offset = xdr->buf->len;
3054 	attrlen_p = xdr_reserve_space(xdr, XDR_UNIT);
3055 	if (!attrlen_p)
3056 		goto out_resource;
3057 
3058 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
3059 		u32 supp[3];
3060 
3061 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
3062 
3063 		if (!IS_POSIXACL(dentry->d_inode))
3064 			supp[0] &= ~FATTR4_WORD0_ACL;
3065 		if (!contextsupport)
3066 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
3067 		if (!supp[2]) {
3068 			p = xdr_reserve_space(xdr, 12);
3069 			if (!p)
3070 				goto out_resource;
3071 			*p++ = cpu_to_be32(2);
3072 			*p++ = cpu_to_be32(supp[0]);
3073 			*p++ = cpu_to_be32(supp[1]);
3074 		} else {
3075 			p = xdr_reserve_space(xdr, 16);
3076 			if (!p)
3077 				goto out_resource;
3078 			*p++ = cpu_to_be32(3);
3079 			*p++ = cpu_to_be32(supp[0]);
3080 			*p++ = cpu_to_be32(supp[1]);
3081 			*p++ = cpu_to_be32(supp[2]);
3082 		}
3083 	}
3084 	if (bmval0 & FATTR4_WORD0_TYPE) {
3085 		p = xdr_reserve_space(xdr, 4);
3086 		if (!p)
3087 			goto out_resource;
3088 		dummy = nfs4_file_type(stat.mode);
3089 		if (dummy == NF4BAD) {
3090 			status = nfserr_serverfault;
3091 			goto out;
3092 		}
3093 		*p++ = cpu_to_be32(dummy);
3094 	}
3095 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
3096 		p = xdr_reserve_space(xdr, 4);
3097 		if (!p)
3098 			goto out_resource;
3099 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
3100 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
3101 		else
3102 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
3103 						NFS4_FH_VOL_RENAME);
3104 	}
3105 	if (bmval0 & FATTR4_WORD0_CHANGE) {
3106 		p = xdr_reserve_space(xdr, 8);
3107 		if (!p)
3108 			goto out_resource;
3109 		p = encode_change(p, &stat, d_inode(dentry), exp);
3110 	}
3111 	if (bmval0 & FATTR4_WORD0_SIZE) {
3112 		p = xdr_reserve_space(xdr, 8);
3113 		if (!p)
3114 			goto out_resource;
3115 		p = xdr_encode_hyper(p, stat.size);
3116 	}
3117 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
3118 		p = xdr_reserve_space(xdr, 4);
3119 		if (!p)
3120 			goto out_resource;
3121 		*p++ = cpu_to_be32(1);
3122 	}
3123 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
3124 		p = xdr_reserve_space(xdr, 4);
3125 		if (!p)
3126 			goto out_resource;
3127 		*p++ = cpu_to_be32(1);
3128 	}
3129 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
3130 		p = xdr_reserve_space(xdr, 4);
3131 		if (!p)
3132 			goto out_resource;
3133 		*p++ = cpu_to_be32(0);
3134 	}
3135 	if (bmval0 & FATTR4_WORD0_FSID) {
3136 		p = xdr_reserve_space(xdr, 16);
3137 		if (!p)
3138 			goto out_resource;
3139 		if (exp->ex_fslocs.migrated) {
3140 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
3141 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
3142 		} else switch(fsid_source(fhp)) {
3143 		case FSIDSOURCE_FSID:
3144 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
3145 			p = xdr_encode_hyper(p, (u64)0);
3146 			break;
3147 		case FSIDSOURCE_DEV:
3148 			*p++ = cpu_to_be32(0);
3149 			*p++ = cpu_to_be32(MAJOR(stat.dev));
3150 			*p++ = cpu_to_be32(0);
3151 			*p++ = cpu_to_be32(MINOR(stat.dev));
3152 			break;
3153 		case FSIDSOURCE_UUID:
3154 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
3155 								EX_UUID_LEN);
3156 			break;
3157 		}
3158 	}
3159 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
3160 		p = xdr_reserve_space(xdr, 4);
3161 		if (!p)
3162 			goto out_resource;
3163 		*p++ = cpu_to_be32(0);
3164 	}
3165 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
3166 		p = xdr_reserve_space(xdr, 4);
3167 		if (!p)
3168 			goto out_resource;
3169 		*p++ = cpu_to_be32(nn->nfsd4_lease);
3170 	}
3171 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
3172 		p = xdr_reserve_space(xdr, 4);
3173 		if (!p)
3174 			goto out_resource;
3175 		*p++ = cpu_to_be32(rdattr_err);
3176 	}
3177 	if (bmval0 & FATTR4_WORD0_ACL) {
3178 		struct nfs4_ace *ace;
3179 
3180 		if (acl == NULL) {
3181 			p = xdr_reserve_space(xdr, 4);
3182 			if (!p)
3183 				goto out_resource;
3184 
3185 			*p++ = cpu_to_be32(0);
3186 			goto out_acl;
3187 		}
3188 		p = xdr_reserve_space(xdr, 4);
3189 		if (!p)
3190 			goto out_resource;
3191 		*p++ = cpu_to_be32(acl->naces);
3192 
3193 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3194 			p = xdr_reserve_space(xdr, 4*3);
3195 			if (!p)
3196 				goto out_resource;
3197 			*p++ = cpu_to_be32(ace->type);
3198 			*p++ = cpu_to_be32(ace->flag);
3199 			*p++ = cpu_to_be32(ace->access_mask &
3200 							NFS4_ACE_MASK_ALL);
3201 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
3202 			if (status)
3203 				goto out;
3204 		}
3205 	}
3206 out_acl:
3207 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
3208 		p = xdr_reserve_space(xdr, 4);
3209 		if (!p)
3210 			goto out_resource;
3211 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
3212 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
3213 	}
3214 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
3215 		p = xdr_reserve_space(xdr, 4);
3216 		if (!p)
3217 			goto out_resource;
3218 		*p++ = cpu_to_be32(1);
3219 	}
3220 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
3221 		p = xdr_reserve_space(xdr, 4);
3222 		if (!p)
3223 			goto out_resource;
3224 		*p++ = cpu_to_be32(0);
3225 	}
3226 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
3227 		p = xdr_reserve_space(xdr, 4);
3228 		if (!p)
3229 			goto out_resource;
3230 		*p++ = cpu_to_be32(1);
3231 	}
3232 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
3233 		p = xdr_reserve_space(xdr, 4);
3234 		if (!p)
3235 			goto out_resource;
3236 		*p++ = cpu_to_be32(1);
3237 	}
3238 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
3239 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
3240 		if (!p)
3241 			goto out_resource;
3242 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw,
3243 					fhp->fh_handle.fh_size);
3244 	}
3245 	if (bmval0 & FATTR4_WORD0_FILEID) {
3246 		p = xdr_reserve_space(xdr, 8);
3247 		if (!p)
3248 			goto out_resource;
3249 		p = xdr_encode_hyper(p, stat.ino);
3250 	}
3251 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
3252 		p = xdr_reserve_space(xdr, 8);
3253 		if (!p)
3254 			goto out_resource;
3255 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3256 	}
3257 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
3258 		p = xdr_reserve_space(xdr, 8);
3259 		if (!p)
3260 			goto out_resource;
3261 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
3262 	}
3263 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
3264 		p = xdr_reserve_space(xdr, 8);
3265 		if (!p)
3266 			goto out_resource;
3267 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
3268 	}
3269 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
3270 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
3271 		if (status)
3272 			goto out;
3273 	}
3274 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
3275 		p = xdr_reserve_space(xdr, 4);
3276 		if (!p)
3277 			goto out_resource;
3278 		*p++ = cpu_to_be32(1);
3279 	}
3280 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
3281 		p = xdr_reserve_space(xdr, 8);
3282 		if (!p)
3283 			goto out_resource;
3284 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
3285 	}
3286 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
3287 		p = xdr_reserve_space(xdr, 4);
3288 		if (!p)
3289 			goto out_resource;
3290 		*p++ = cpu_to_be32(255);
3291 	}
3292 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
3293 		p = xdr_reserve_space(xdr, 4);
3294 		if (!p)
3295 			goto out_resource;
3296 		*p++ = cpu_to_be32(statfs.f_namelen);
3297 	}
3298 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
3299 		p = xdr_reserve_space(xdr, 8);
3300 		if (!p)
3301 			goto out_resource;
3302 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3303 	}
3304 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
3305 		p = xdr_reserve_space(xdr, 8);
3306 		if (!p)
3307 			goto out_resource;
3308 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
3309 	}
3310 	if (bmval1 & FATTR4_WORD1_MODE) {
3311 		p = xdr_reserve_space(xdr, 4);
3312 		if (!p)
3313 			goto out_resource;
3314 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
3315 	}
3316 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
3317 		p = xdr_reserve_space(xdr, 4);
3318 		if (!p)
3319 			goto out_resource;
3320 		*p++ = cpu_to_be32(1);
3321 	}
3322 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
3323 		p = xdr_reserve_space(xdr, 4);
3324 		if (!p)
3325 			goto out_resource;
3326 		*p++ = cpu_to_be32(stat.nlink);
3327 	}
3328 	if (bmval1 & FATTR4_WORD1_OWNER) {
3329 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
3330 		if (status)
3331 			goto out;
3332 	}
3333 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
3334 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
3335 		if (status)
3336 			goto out;
3337 	}
3338 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
3339 		p = xdr_reserve_space(xdr, 8);
3340 		if (!p)
3341 			goto out_resource;
3342 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
3343 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
3344 	}
3345 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
3346 		p = xdr_reserve_space(xdr, 8);
3347 		if (!p)
3348 			goto out_resource;
3349 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
3350 		p = xdr_encode_hyper(p, dummy64);
3351 	}
3352 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
3353 		p = xdr_reserve_space(xdr, 8);
3354 		if (!p)
3355 			goto out_resource;
3356 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
3357 		p = xdr_encode_hyper(p, dummy64);
3358 	}
3359 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
3360 		p = xdr_reserve_space(xdr, 8);
3361 		if (!p)
3362 			goto out_resource;
3363 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
3364 		p = xdr_encode_hyper(p, dummy64);
3365 	}
3366 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
3367 		p = xdr_reserve_space(xdr, 8);
3368 		if (!p)
3369 			goto out_resource;
3370 		dummy64 = (u64)stat.blocks << 9;
3371 		p = xdr_encode_hyper(p, dummy64);
3372 	}
3373 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
3374 		status = nfsd4_encode_nfstime4(xdr, &stat.atime);
3375 		if (status)
3376 			goto out;
3377 	}
3378 	if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
3379 		status = nfsd4_encode_nfstime4(xdr, &stat.btime);
3380 		if (status)
3381 			goto out;
3382 	}
3383 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
3384 		p = xdr_reserve_space(xdr, 12);
3385 		if (!p)
3386 			goto out_resource;
3387 		p = encode_time_delta(p, d_inode(dentry));
3388 	}
3389 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
3390 		status = nfsd4_encode_nfstime4(xdr, &stat.ctime);
3391 		if (status)
3392 			goto out;
3393 	}
3394 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
3395 		status = nfsd4_encode_nfstime4(xdr, &stat.mtime);
3396 		if (status)
3397 			goto out;
3398 	}
3399 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
3400 		u64 ino = stat.ino;
3401 
3402 		p = xdr_reserve_space(xdr, 8);
3403 		if (!p)
3404                 	goto out_resource;
3405 		/*
3406 		 * Get ino of mountpoint in parent filesystem, if not ignoring
3407 		 * crossmount and this is the root of a cross-mounted
3408 		 * filesystem.
3409 		 */
3410 		if (ignore_crossmnt == 0 &&
3411 		    dentry == exp->ex_path.mnt->mnt_root) {
3412 			err = nfsd4_get_mounted_on_ino(exp, &ino);
3413 			if (err)
3414 				goto out_nfserr;
3415 		}
3416 		p = xdr_encode_hyper(p, ino);
3417 	}
3418 #ifdef CONFIG_NFSD_PNFS
3419 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
3420 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3421 		if (status)
3422 			goto out;
3423 	}
3424 
3425 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
3426 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
3427 		if (status)
3428 			goto out;
3429 	}
3430 
3431 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
3432 		p = xdr_reserve_space(xdr, 4);
3433 		if (!p)
3434 			goto out_resource;
3435 		*p++ = cpu_to_be32(stat.blksize);
3436 	}
3437 #endif /* CONFIG_NFSD_PNFS */
3438 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
3439 		u32 supp[3];
3440 
3441 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
3442 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3443 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3444 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3445 
3446 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
3447 		if (status)
3448 			goto out;
3449 	}
3450 
3451 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3452 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
3453 		status = nfsd4_encode_security_label(xdr, rqstp, context,
3454 								contextlen);
3455 		if (status)
3456 			goto out;
3457 	}
3458 #endif
3459 
3460 	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
3461 		p = xdr_reserve_space(xdr, 4);
3462 		if (!p)
3463 			goto out_resource;
3464 		err = xattr_supports_user_prefix(d_inode(dentry));
3465 		*p++ = cpu_to_be32(err == 0);
3466 	}
3467 
3468 	*attrlen_p = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
3469 	status = nfs_ok;
3470 
3471 out:
3472 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3473 	if (context)
3474 		security_release_secctx(context, contextlen);
3475 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3476 	kfree(acl);
3477 	if (tempfh) {
3478 		fh_put(tempfh);
3479 		kfree(tempfh);
3480 	}
3481 	if (status)
3482 		xdr_truncate_encode(xdr, starting_len);
3483 	return status;
3484 out_nfserr:
3485 	status = nfserrno(err);
3486 	goto out;
3487 out_resource:
3488 	status = nfserr_resource;
3489 	goto out;
3490 }
3491 
3492 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3493 				struct xdr_buf *buf, __be32 *p, int bytes)
3494 {
3495 	xdr->scratch.iov_len = 0;
3496 	memset(buf, 0, sizeof(struct xdr_buf));
3497 	buf->head[0].iov_base = p;
3498 	buf->head[0].iov_len = 0;
3499 	buf->len = 0;
3500 	xdr->buf = buf;
3501 	xdr->iov = buf->head;
3502 	xdr->p = p;
3503 	xdr->end = (void *)p + bytes;
3504 	buf->buflen = bytes;
3505 }
3506 
3507 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3508 			struct svc_fh *fhp, struct svc_export *exp,
3509 			struct dentry *dentry, u32 *bmval,
3510 			struct svc_rqst *rqstp, int ignore_crossmnt)
3511 {
3512 	struct xdr_buf dummy;
3513 	struct xdr_stream xdr;
3514 	__be32 ret;
3515 
3516 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3517 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
3518 							ignore_crossmnt);
3519 	*p = xdr.p;
3520 	return ret;
3521 }
3522 
3523 static inline int attributes_need_mount(u32 *bmval)
3524 {
3525 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3526 		return 1;
3527 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3528 		return 1;
3529 	return 0;
3530 }
3531 
3532 static __be32
3533 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
3534 			const char *name, int namlen)
3535 {
3536 	struct svc_export *exp = cd->rd_fhp->fh_export;
3537 	struct dentry *dentry;
3538 	__be32 nfserr;
3539 	int ignore_crossmnt = 0;
3540 
3541 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3542 	if (IS_ERR(dentry))
3543 		return nfserrno(PTR_ERR(dentry));
3544 
3545 	exp_get(exp);
3546 	/*
3547 	 * In the case of a mountpoint, the client may be asking for
3548 	 * attributes that are only properties of the underlying filesystem
3549 	 * as opposed to the cross-mounted file system. In such a case,
3550 	 * we will not follow the cross mount and will fill the attribtutes
3551 	 * directly from the mountpoint dentry.
3552 	 */
3553 	if (nfsd_mountpoint(dentry, exp)) {
3554 		int err;
3555 
3556 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3557 				&& !attributes_need_mount(cd->rd_bmval)) {
3558 			ignore_crossmnt = 1;
3559 			goto out_encode;
3560 		}
3561 		/*
3562 		 * Why the heck aren't we just using nfsd_lookup??
3563 		 * Different "."/".." handling?  Something else?
3564 		 * At least, add a comment here to explain....
3565 		 */
3566 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3567 		if (err) {
3568 			nfserr = nfserrno(err);
3569 			goto out_put;
3570 		}
3571 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3572 		if (nfserr)
3573 			goto out_put;
3574 
3575 	}
3576 out_encode:
3577 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
3578 					cd->rd_rqstp, ignore_crossmnt);
3579 out_put:
3580 	dput(dentry);
3581 	exp_put(exp);
3582 	return nfserr;
3583 }
3584 
3585 static __be32 *
3586 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3587 {
3588 	__be32 *p;
3589 
3590 	p = xdr_reserve_space(xdr, 20);
3591 	if (!p)
3592 		return NULL;
3593 	*p++ = htonl(2);
3594 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3595 	*p++ = htonl(0);			 /* bmval1 */
3596 
3597 	*p++ = htonl(4);     /* attribute length */
3598 	*p++ = nfserr;       /* no htonl */
3599 	return p;
3600 }
3601 
3602 static int
3603 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3604 		    loff_t offset, u64 ino, unsigned int d_type)
3605 {
3606 	struct readdir_cd *ccd = ccdv;
3607 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3608 	struct xdr_stream *xdr = cd->xdr;
3609 	int start_offset = xdr->buf->len;
3610 	int cookie_offset;
3611 	u32 name_and_cookie;
3612 	int entry_bytes;
3613 	__be32 nfserr = nfserr_toosmall;
3614 	__be64 wire_offset;
3615 	__be32 *p;
3616 
3617 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3618 	if (name && isdotent(name, namlen)) {
3619 		cd->common.err = nfs_ok;
3620 		return 0;
3621 	}
3622 
3623 	if (cd->cookie_offset) {
3624 		wire_offset = cpu_to_be64(offset);
3625 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3626 							&wire_offset, 8);
3627 	}
3628 
3629 	p = xdr_reserve_space(xdr, 4);
3630 	if (!p)
3631 		goto fail;
3632 	*p++ = xdr_one;                             /* mark entry present */
3633 	cookie_offset = xdr->buf->len;
3634 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3635 	if (!p)
3636 		goto fail;
3637 	p = xdr_encode_hyper(p, OFFSET_MAX);        /* offset of next entry */
3638 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3639 
3640 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3641 	switch (nfserr) {
3642 	case nfs_ok:
3643 		break;
3644 	case nfserr_resource:
3645 		nfserr = nfserr_toosmall;
3646 		goto fail;
3647 	case nfserr_noent:
3648 		xdr_truncate_encode(xdr, start_offset);
3649 		goto skip_entry;
3650 	case nfserr_jukebox:
3651 		/*
3652 		 * The pseudoroot should only display dentries that lead to
3653 		 * exports. If we get EJUKEBOX here, then we can't tell whether
3654 		 * this entry should be included. Just fail the whole READDIR
3655 		 * with NFS4ERR_DELAY in that case, and hope that the situation
3656 		 * will resolve itself by the client's next attempt.
3657 		 */
3658 		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
3659 			goto fail;
3660 		fallthrough;
3661 	default:
3662 		/*
3663 		 * If the client requested the RDATTR_ERROR attribute,
3664 		 * we stuff the error code into this attribute
3665 		 * and continue.  If this attribute was not requested,
3666 		 * then in accordance with the spec, we fail the
3667 		 * entire READDIR operation(!)
3668 		 */
3669 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3670 			goto fail;
3671 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3672 		if (p == NULL) {
3673 			nfserr = nfserr_toosmall;
3674 			goto fail;
3675 		}
3676 	}
3677 	nfserr = nfserr_toosmall;
3678 	entry_bytes = xdr->buf->len - start_offset;
3679 	if (entry_bytes > cd->rd_maxcount)
3680 		goto fail;
3681 	cd->rd_maxcount -= entry_bytes;
3682 	/*
3683 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3684 	 * notes that it could be zero. If it is zero, then the server
3685 	 * should enforce only the rd_maxcount value.
3686 	 */
3687 	if (cd->rd_dircount) {
3688 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3689 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3690 			goto fail;
3691 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3692 		if (!cd->rd_dircount)
3693 			cd->rd_maxcount = 0;
3694 	}
3695 
3696 	cd->cookie_offset = cookie_offset;
3697 skip_entry:
3698 	cd->common.err = nfs_ok;
3699 	return 0;
3700 fail:
3701 	xdr_truncate_encode(xdr, start_offset);
3702 	cd->common.err = nfserr;
3703 	return -EINVAL;
3704 }
3705 
3706 static __be32
3707 nfsd4_encode_verifier4(struct xdr_stream *xdr, const nfs4_verifier *verf)
3708 {
3709 	__be32 *p;
3710 
3711 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3712 	if (!p)
3713 		return nfserr_resource;
3714 	memcpy(p, verf->data, sizeof(verf->data));
3715 	return nfs_ok;
3716 }
3717 
3718 static __be32
3719 nfsd4_encode_clientid4(struct xdr_stream *xdr, const clientid_t *clientid)
3720 {
3721 	__be32 *p;
3722 
3723 	p = xdr_reserve_space(xdr, sizeof(__be64));
3724 	if (!p)
3725 		return nfserr_resource;
3726 	memcpy(p, clientid, sizeof(*clientid));
3727 	return nfs_ok;
3728 }
3729 
3730 static __be32
3731 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3732 {
3733 	__be32 *p;
3734 
3735 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3736 	if (!p)
3737 		return nfserr_resource;
3738 	*p++ = cpu_to_be32(sid->si_generation);
3739 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3740 					sizeof(stateid_opaque_t));
3741 	return 0;
3742 }
3743 
3744 static __be32
3745 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr,
3746 		    union nfsd4_op_u *u)
3747 {
3748 	struct nfsd4_access *access = &u->access;
3749 	struct xdr_stream *xdr = resp->xdr;
3750 	__be32 *p;
3751 
3752 	p = xdr_reserve_space(xdr, 8);
3753 	if (!p)
3754 		return nfserr_resource;
3755 	*p++ = cpu_to_be32(access->ac_supported);
3756 	*p++ = cpu_to_be32(access->ac_resp_access);
3757 	return 0;
3758 }
3759 
3760 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr,
3761 						union nfsd4_op_u *u)
3762 {
3763 	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
3764 	struct xdr_stream *xdr = resp->xdr;
3765 	__be32 *p;
3766 
3767 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3768 	if (!p)
3769 		return nfserr_resource;
3770 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3771 					NFS4_MAX_SESSIONID_LEN);
3772 	*p++ = cpu_to_be32(bcts->dir);
3773 	/* Upshifting from TCP to RDMA is not supported */
3774 	*p++ = cpu_to_be32(0);
3775 	return 0;
3776 }
3777 
3778 static __be32
3779 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr,
3780 		   union nfsd4_op_u *u)
3781 {
3782 	struct nfsd4_close *close = &u->close;
3783 	struct xdr_stream *xdr = resp->xdr;
3784 
3785 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3786 }
3787 
3788 
3789 static __be32
3790 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr,
3791 		    union nfsd4_op_u *u)
3792 {
3793 	struct nfsd4_commit *commit = &u->commit;
3794 
3795 	return nfsd4_encode_verifier4(resp->xdr, &commit->co_verf);
3796 }
3797 
3798 static __be32
3799 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr,
3800 		    union nfsd4_op_u *u)
3801 {
3802 	struct nfsd4_create *create = &u->create;
3803 	struct xdr_stream *xdr = resp->xdr;
3804 
3805 	nfserr = nfsd4_encode_change_info4(xdr, &create->cr_cinfo);
3806 	if (nfserr)
3807 		return nfserr;
3808 	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3809 			create->cr_bmval[1], create->cr_bmval[2]);
3810 }
3811 
3812 static __be32
3813 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr,
3814 		     union nfsd4_op_u *u)
3815 {
3816 	struct nfsd4_getattr *getattr = &u->getattr;
3817 	struct svc_fh *fhp = getattr->ga_fhp;
3818 	struct xdr_stream *xdr = resp->xdr;
3819 
3820 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3821 				    getattr->ga_bmval, resp->rqstp, 0);
3822 }
3823 
3824 static __be32
3825 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr,
3826 		   union nfsd4_op_u *u)
3827 {
3828 	struct svc_fh **fhpp = &u->getfh;
3829 	struct xdr_stream *xdr = resp->xdr;
3830 	struct svc_fh *fhp = *fhpp;
3831 	unsigned int len;
3832 	__be32 *p;
3833 
3834 	len = fhp->fh_handle.fh_size;
3835 	p = xdr_reserve_space(xdr, len + 4);
3836 	if (!p)
3837 		return nfserr_resource;
3838 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw, len);
3839 	return 0;
3840 }
3841 
3842 /*
3843 * Including all fields other than the name, a LOCK4denied structure requires
3844 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3845 */
3846 static __be32
3847 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3848 {
3849 	struct xdr_netobj *conf = &ld->ld_owner;
3850 	__be32 *p;
3851 
3852 again:
3853 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3854 	if (!p) {
3855 		/*
3856 		 * Don't fail to return the result just because we can't
3857 		 * return the conflicting open:
3858 		 */
3859 		if (conf->len) {
3860 			kfree(conf->data);
3861 			conf->len = 0;
3862 			conf->data = NULL;
3863 			goto again;
3864 		}
3865 		return nfserr_resource;
3866 	}
3867 	p = xdr_encode_hyper(p, ld->ld_start);
3868 	p = xdr_encode_hyper(p, ld->ld_length);
3869 	*p++ = cpu_to_be32(ld->ld_type);
3870 	if (conf->len) {
3871 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3872 		p = xdr_encode_opaque(p, conf->data, conf->len);
3873 		kfree(conf->data);
3874 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3875 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3876 		*p++ = cpu_to_be32(0); /* length of owner name */
3877 	}
3878 	return nfserr_denied;
3879 }
3880 
3881 static __be32
3882 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr,
3883 		  union nfsd4_op_u *u)
3884 {
3885 	struct nfsd4_lock *lock = &u->lock;
3886 	struct xdr_stream *xdr = resp->xdr;
3887 
3888 	if (!nfserr)
3889 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3890 	else if (nfserr == nfserr_denied)
3891 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3892 
3893 	return nfserr;
3894 }
3895 
3896 static __be32
3897 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr,
3898 		   union nfsd4_op_u *u)
3899 {
3900 	struct nfsd4_lockt *lockt = &u->lockt;
3901 	struct xdr_stream *xdr = resp->xdr;
3902 
3903 	if (nfserr == nfserr_denied)
3904 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3905 	return nfserr;
3906 }
3907 
3908 static __be32
3909 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr,
3910 		   union nfsd4_op_u *u)
3911 {
3912 	struct nfsd4_locku *locku = &u->locku;
3913 	struct xdr_stream *xdr = resp->xdr;
3914 
3915 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3916 }
3917 
3918 
3919 static __be32
3920 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr,
3921 		  union nfsd4_op_u *u)
3922 {
3923 	struct nfsd4_link *link = &u->link;
3924 	struct xdr_stream *xdr = resp->xdr;
3925 
3926 	return nfsd4_encode_change_info4(xdr, &link->li_cinfo);
3927 }
3928 
3929 
3930 static __be32
3931 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
3932 		  union nfsd4_op_u *u)
3933 {
3934 	struct nfsd4_open *open = &u->open;
3935 	struct xdr_stream *xdr = resp->xdr;
3936 	__be32 *p;
3937 
3938 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3939 	if (nfserr)
3940 		return nfserr;
3941 	nfserr = nfsd4_encode_change_info4(xdr, &open->op_cinfo);
3942 	if (nfserr)
3943 		return nfserr;
3944 	if (xdr_stream_encode_u32(xdr, open->op_rflags) < 0)
3945 		return nfserr_resource;
3946 
3947 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3948 					open->op_bmval[2]);
3949 	if (nfserr)
3950 		return nfserr;
3951 
3952 	p = xdr_reserve_space(xdr, 4);
3953 	if (!p)
3954 		return nfserr_resource;
3955 
3956 	*p++ = cpu_to_be32(open->op_delegate_type);
3957 	switch (open->op_delegate_type) {
3958 	case NFS4_OPEN_DELEGATE_NONE:
3959 		break;
3960 	case NFS4_OPEN_DELEGATE_READ:
3961 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3962 		if (nfserr)
3963 			return nfserr;
3964 		p = xdr_reserve_space(xdr, 20);
3965 		if (!p)
3966 			return nfserr_resource;
3967 		*p++ = cpu_to_be32(open->op_recall);
3968 
3969 		/*
3970 		 * TODO: ACE's in delegations
3971 		 */
3972 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3973 		*p++ = cpu_to_be32(0);
3974 		*p++ = cpu_to_be32(0);
3975 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3976 		break;
3977 	case NFS4_OPEN_DELEGATE_WRITE:
3978 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3979 		if (nfserr)
3980 			return nfserr;
3981 
3982 		p = xdr_reserve_space(xdr, XDR_UNIT * 8);
3983 		if (!p)
3984 			return nfserr_resource;
3985 		*p++ = cpu_to_be32(open->op_recall);
3986 
3987 		/*
3988 		 * Always flush on close
3989 		 *
3990 		 * TODO: space_limit's in delegations
3991 		 */
3992 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3993 		*p++ = xdr_zero;
3994 		*p++ = xdr_zero;
3995 
3996 		/*
3997 		 * TODO: ACE's in delegations
3998 		 */
3999 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
4000 		*p++ = cpu_to_be32(0);
4001 		*p++ = cpu_to_be32(0);
4002 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
4003 		break;
4004 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
4005 		switch (open->op_why_no_deleg) {
4006 		case WND4_CONTENTION:
4007 		case WND4_RESOURCE:
4008 			p = xdr_reserve_space(xdr, 8);
4009 			if (!p)
4010 				return nfserr_resource;
4011 			*p++ = cpu_to_be32(open->op_why_no_deleg);
4012 			/* deleg signaling not supported yet: */
4013 			*p++ = cpu_to_be32(0);
4014 			break;
4015 		default:
4016 			p = xdr_reserve_space(xdr, 4);
4017 			if (!p)
4018 				return nfserr_resource;
4019 			*p++ = cpu_to_be32(open->op_why_no_deleg);
4020 		}
4021 		break;
4022 	default:
4023 		BUG();
4024 	}
4025 	/* XXX save filehandle here */
4026 	return 0;
4027 }
4028 
4029 static __be32
4030 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr,
4031 			  union nfsd4_op_u *u)
4032 {
4033 	struct nfsd4_open_confirm *oc = &u->open_confirm;
4034 	struct xdr_stream *xdr = resp->xdr;
4035 
4036 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
4037 }
4038 
4039 static __be32
4040 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr,
4041 			    union nfsd4_op_u *u)
4042 {
4043 	struct nfsd4_open_downgrade *od = &u->open_downgrade;
4044 	struct xdr_stream *xdr = resp->xdr;
4045 
4046 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
4047 }
4048 
4049 /*
4050  * The operation of this function assumes that this is the only
4051  * READ operation in the COMPOUND. If there are multiple READs,
4052  * we use nfsd4_encode_readv().
4053  */
4054 static __be32 nfsd4_encode_splice_read(
4055 				struct nfsd4_compoundres *resp,
4056 				struct nfsd4_read *read,
4057 				struct file *file, unsigned long maxcount)
4058 {
4059 	struct xdr_stream *xdr = resp->xdr;
4060 	struct xdr_buf *buf = xdr->buf;
4061 	int status, space_left;
4062 	__be32 nfserr;
4063 
4064 	/*
4065 	 * Make sure there is room at the end of buf->head for
4066 	 * svcxdr_encode_opaque_pages() to create a tail buffer
4067 	 * to XDR-pad the payload.
4068 	 */
4069 	if (xdr->iov != xdr->buf->head || xdr->end - xdr->p < 1)
4070 		return nfserr_resource;
4071 
4072 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
4073 				  file, read->rd_offset, &maxcount,
4074 				  &read->rd_eof);
4075 	read->rd_length = maxcount;
4076 	if (nfserr)
4077 		goto out_err;
4078 	svcxdr_encode_opaque_pages(read->rd_rqstp, xdr, buf->pages,
4079 				   buf->page_base, maxcount);
4080 	status = svc_encode_result_payload(read->rd_rqstp,
4081 					   buf->head[0].iov_len, maxcount);
4082 	if (status) {
4083 		nfserr = nfserrno(status);
4084 		goto out_err;
4085 	}
4086 
4087 	/*
4088 	 * Prepare to encode subsequent operations.
4089 	 *
4090 	 * xdr_truncate_encode() is not safe to use after a successful
4091 	 * splice read has been done, so the following stream
4092 	 * manipulations are open-coded.
4093 	 */
4094 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
4095 				buf->buflen - buf->len);
4096 	buf->buflen = buf->len + space_left;
4097 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
4098 
4099 	return nfs_ok;
4100 
4101 out_err:
4102 	/*
4103 	 * nfsd_splice_actor may have already messed with the
4104 	 * page length; reset it so as not to confuse
4105 	 * xdr_truncate_encode in our caller.
4106 	 */
4107 	buf->page_len = 0;
4108 	return nfserr;
4109 }
4110 
4111 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
4112 				 struct nfsd4_read *read,
4113 				 struct file *file, unsigned long maxcount)
4114 {
4115 	struct xdr_stream *xdr = resp->xdr;
4116 	unsigned int starting_len = xdr->buf->len;
4117 	__be32 zero = xdr_zero;
4118 	__be32 nfserr;
4119 
4120 	if (xdr_reserve_space_vec(xdr, maxcount) < 0)
4121 		return nfserr_resource;
4122 
4123 	nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, file,
4124 				read->rd_offset, &maxcount,
4125 				xdr->buf->page_len & ~PAGE_MASK,
4126 				&read->rd_eof);
4127 	read->rd_length = maxcount;
4128 	if (nfserr)
4129 		return nfserr;
4130 	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
4131 		return nfserr_io;
4132 	xdr_truncate_encode(xdr, starting_len + xdr_align_size(maxcount));
4133 
4134 	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
4135 			       xdr_pad_size(maxcount));
4136 	return nfs_ok;
4137 }
4138 
4139 static __be32
4140 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
4141 		  union nfsd4_op_u *u)
4142 {
4143 	struct nfsd4_read *read = &u->read;
4144 	bool splice_ok = test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags);
4145 	unsigned long maxcount;
4146 	struct xdr_stream *xdr = resp->xdr;
4147 	struct file *file;
4148 	int starting_len = xdr->buf->len;
4149 	__be32 *p;
4150 
4151 	if (nfserr)
4152 		return nfserr;
4153 	file = read->rd_nf->nf_file;
4154 
4155 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
4156 	if (!p) {
4157 		WARN_ON_ONCE(splice_ok);
4158 		return nfserr_resource;
4159 	}
4160 	if (resp->xdr->buf->page_len && splice_ok) {
4161 		WARN_ON_ONCE(1);
4162 		return nfserr_serverfault;
4163 	}
4164 	xdr_commit_encode(xdr);
4165 
4166 	maxcount = min_t(unsigned long, read->rd_length,
4167 			 (xdr->buf->buflen - xdr->buf->len));
4168 
4169 	if (file->f_op->splice_read && splice_ok)
4170 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4171 	else
4172 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4173 	if (nfserr) {
4174 		xdr_truncate_encode(xdr, starting_len);
4175 		return nfserr;
4176 	}
4177 
4178 	p = xdr_encode_bool(p, read->rd_eof);
4179 	*p = cpu_to_be32(read->rd_length);
4180 	return nfs_ok;
4181 }
4182 
4183 static __be32
4184 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr,
4185 		      union nfsd4_op_u *u)
4186 {
4187 	struct nfsd4_readlink *readlink = &u->readlink;
4188 	__be32 *p, *maxcount_p, zero = xdr_zero;
4189 	struct xdr_stream *xdr = resp->xdr;
4190 	int length_offset = xdr->buf->len;
4191 	int maxcount, status;
4192 
4193 	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
4194 	if (!maxcount_p)
4195 		return nfserr_resource;
4196 	maxcount = PAGE_SIZE;
4197 
4198 	p = xdr_reserve_space(xdr, maxcount);
4199 	if (!p)
4200 		return nfserr_resource;
4201 	/*
4202 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4203 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4204 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4205 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4206 	 */
4207 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4208 						(char *)p, &maxcount);
4209 	if (nfserr == nfserr_isdir)
4210 		nfserr = nfserr_inval;
4211 	if (nfserr)
4212 		goto out_err;
4213 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4214 					   maxcount);
4215 	if (status) {
4216 		nfserr = nfserrno(status);
4217 		goto out_err;
4218 	}
4219 	*maxcount_p = cpu_to_be32(maxcount);
4220 	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
4221 	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
4222 			       xdr_pad_size(maxcount));
4223 	return nfs_ok;
4224 
4225 out_err:
4226 	xdr_truncate_encode(xdr, length_offset);
4227 	return nfserr;
4228 }
4229 
4230 static __be32
4231 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr,
4232 		     union nfsd4_op_u *u)
4233 {
4234 	struct nfsd4_readdir *readdir = &u->readdir;
4235 	int maxcount;
4236 	int bytes_left;
4237 	loff_t offset;
4238 	__be64 wire_offset;
4239 	struct xdr_stream *xdr = resp->xdr;
4240 	int starting_len = xdr->buf->len;
4241 	__be32 *p;
4242 
4243 	nfserr = nfsd4_encode_verifier4(xdr, &readdir->rd_verf);
4244 	if (nfserr != nfs_ok)
4245 		return nfserr;
4246 
4247 	/*
4248 	 * Number of bytes left for directory entries allowing for the
4249 	 * final 8 bytes of the readdir and a following failed op:
4250 	 */
4251 	bytes_left = xdr->buf->buflen - xdr->buf->len
4252 			- COMPOUND_ERR_SLACK_SPACE - 8;
4253 	if (bytes_left < 0) {
4254 		nfserr = nfserr_resource;
4255 		goto err_no_verf;
4256 	}
4257 	maxcount = svc_max_payload(resp->rqstp);
4258 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
4259 	/*
4260 	 * Note the rfc defines rd_maxcount as the size of the
4261 	 * READDIR4resok structure, which includes the verifier above
4262 	 * and the 8 bytes encoded at the end of this function:
4263 	 */
4264 	if (maxcount < 16) {
4265 		nfserr = nfserr_toosmall;
4266 		goto err_no_verf;
4267 	}
4268 	maxcount = min_t(int, maxcount-16, bytes_left);
4269 
4270 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
4271 	if (!readdir->rd_dircount)
4272 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
4273 
4274 	readdir->xdr = xdr;
4275 	readdir->rd_maxcount = maxcount;
4276 	readdir->common.err = 0;
4277 	readdir->cookie_offset = 0;
4278 
4279 	offset = readdir->rd_cookie;
4280 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
4281 			      &offset,
4282 			      &readdir->common, nfsd4_encode_dirent);
4283 	if (nfserr == nfs_ok &&
4284 	    readdir->common.err == nfserr_toosmall &&
4285 	    xdr->buf->len == starting_len + 8) {
4286 		/* nothing encoded; which limit did we hit?: */
4287 		if (maxcount - 16 < bytes_left)
4288 			/* It was the fault of rd_maxcount: */
4289 			nfserr = nfserr_toosmall;
4290 		else
4291 			/* We ran out of buffer space: */
4292 			nfserr = nfserr_resource;
4293 	}
4294 	if (nfserr)
4295 		goto err_no_verf;
4296 
4297 	if (readdir->cookie_offset) {
4298 		wire_offset = cpu_to_be64(offset);
4299 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
4300 							&wire_offset, 8);
4301 	}
4302 
4303 	p = xdr_reserve_space(xdr, 8);
4304 	if (!p) {
4305 		WARN_ON_ONCE(1);
4306 		goto err_no_verf;
4307 	}
4308 	*p++ = 0;	/* no more entries */
4309 	*p++ = htonl(readdir->common.err == nfserr_eof);
4310 
4311 	return 0;
4312 err_no_verf:
4313 	xdr_truncate_encode(xdr, starting_len);
4314 	return nfserr;
4315 }
4316 
4317 static __be32
4318 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr,
4319 		    union nfsd4_op_u *u)
4320 {
4321 	struct nfsd4_remove *remove = &u->remove;
4322 	struct xdr_stream *xdr = resp->xdr;
4323 
4324 	return nfsd4_encode_change_info4(xdr, &remove->rm_cinfo);
4325 }
4326 
4327 static __be32
4328 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr,
4329 		    union nfsd4_op_u *u)
4330 {
4331 	struct nfsd4_rename *rename = &u->rename;
4332 	struct xdr_stream *xdr = resp->xdr;
4333 
4334 	nfserr = nfsd4_encode_change_info4(xdr, &rename->rn_sinfo);
4335 	if (nfserr)
4336 		return nfserr;
4337 	return nfsd4_encode_change_info4(xdr, &rename->rn_tinfo);
4338 }
4339 
4340 static __be32
4341 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4342 {
4343 	u32 i, nflavs, supported;
4344 	struct exp_flavor_info *flavs;
4345 	struct exp_flavor_info def_flavs[2];
4346 	__be32 *p, *flavorsp;
4347 	static bool report = true;
4348 
4349 	if (exp->ex_nflavors) {
4350 		flavs = exp->ex_flavors;
4351 		nflavs = exp->ex_nflavors;
4352 	} else { /* Handling of some defaults in absence of real secinfo: */
4353 		flavs = def_flavs;
4354 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4355 			nflavs = 2;
4356 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4357 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4358 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4359 			nflavs = 1;
4360 			flavs[0].pseudoflavor
4361 					= svcauth_gss_flavor(exp->ex_client);
4362 		} else {
4363 			nflavs = 1;
4364 			flavs[0].pseudoflavor
4365 					= exp->ex_client->flavour->flavour;
4366 		}
4367 	}
4368 
4369 	supported = 0;
4370 	p = xdr_reserve_space(xdr, 4);
4371 	if (!p)
4372 		return nfserr_resource;
4373 	flavorsp = p++;		/* to be backfilled later */
4374 
4375 	for (i = 0; i < nflavs; i++) {
4376 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4377 		struct rpcsec_gss_info info;
4378 
4379 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4380 			supported++;
4381 			p = xdr_reserve_space(xdr, 4 + 4 +
4382 					      XDR_LEN(info.oid.len) + 4 + 4);
4383 			if (!p)
4384 				return nfserr_resource;
4385 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
4386 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
4387 			*p++ = cpu_to_be32(info.qop);
4388 			*p++ = cpu_to_be32(info.service);
4389 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4390 			supported++;
4391 			p = xdr_reserve_space(xdr, 4);
4392 			if (!p)
4393 				return nfserr_resource;
4394 			*p++ = cpu_to_be32(pf);
4395 		} else {
4396 			if (report)
4397 				pr_warn("NFS: SECINFO: security flavor %u "
4398 					"is not supported\n", pf);
4399 		}
4400 	}
4401 
4402 	if (nflavs != supported)
4403 		report = false;
4404 	*flavorsp = htonl(supported);
4405 	return 0;
4406 }
4407 
4408 static __be32
4409 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4410 		     union nfsd4_op_u *u)
4411 {
4412 	struct nfsd4_secinfo *secinfo = &u->secinfo;
4413 	struct xdr_stream *xdr = resp->xdr;
4414 
4415 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4416 }
4417 
4418 static __be32
4419 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4420 		     union nfsd4_op_u *u)
4421 {
4422 	struct nfsd4_secinfo_no_name *secinfo = &u->secinfo_no_name;
4423 	struct xdr_stream *xdr = resp->xdr;
4424 
4425 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4426 }
4427 
4428 /*
4429  * The SETATTR encode routine is special -- it always encodes a bitmap,
4430  * regardless of the error status.
4431  */
4432 static __be32
4433 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4434 		     union nfsd4_op_u *u)
4435 {
4436 	struct nfsd4_setattr *setattr = &u->setattr;
4437 	struct xdr_stream *xdr = resp->xdr;
4438 	__be32 *p;
4439 
4440 	p = xdr_reserve_space(xdr, 16);
4441 	if (!p)
4442 		return nfserr_resource;
4443 	if (nfserr) {
4444 		*p++ = cpu_to_be32(3);
4445 		*p++ = cpu_to_be32(0);
4446 		*p++ = cpu_to_be32(0);
4447 		*p++ = cpu_to_be32(0);
4448 	}
4449 	else {
4450 		*p++ = cpu_to_be32(3);
4451 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
4452 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
4453 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
4454 	}
4455 	return nfserr;
4456 }
4457 
4458 static __be32
4459 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr,
4460 			 union nfsd4_op_u *u)
4461 {
4462 	struct nfsd4_setclientid *scd = &u->setclientid;
4463 	struct xdr_stream *xdr = resp->xdr;
4464 
4465 	if (!nfserr) {
4466 		nfserr = nfsd4_encode_clientid4(xdr, &scd->se_clientid);
4467 		if (nfserr != nfs_ok)
4468 			goto out;
4469 		nfserr = nfsd4_encode_verifier4(xdr, &scd->se_confirm);
4470 	} else if (nfserr == nfserr_clid_inuse) {
4471 		/* empty network id */
4472 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4473 			nfserr = nfserr_resource;
4474 			goto out;
4475 		}
4476 		/* empty universal address */
4477 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4478 			nfserr = nfserr_resource;
4479 			goto out;
4480 		}
4481 	}
4482 out:
4483 	return nfserr;
4484 }
4485 
4486 static __be32
4487 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr,
4488 		   union nfsd4_op_u *u)
4489 {
4490 	struct nfsd4_write *write = &u->write;
4491 
4492 	if (xdr_stream_encode_u32(resp->xdr, write->wr_bytes_written) < 0)
4493 		return nfserr_resource;
4494 	if (xdr_stream_encode_u32(resp->xdr, write->wr_how_written) < 0)
4495 		return nfserr_resource;
4496 	return nfsd4_encode_verifier4(resp->xdr, &write->wr_verifier);
4497 }
4498 
4499 static __be32
4500 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4501 			 union nfsd4_op_u *u)
4502 {
4503 	struct nfsd4_exchange_id *exid = &u->exchange_id;
4504 	struct xdr_stream *xdr = resp->xdr;
4505 	__be32 *p;
4506 	char *major_id;
4507 	char *server_scope;
4508 	int major_id_sz;
4509 	int server_scope_sz;
4510 	uint64_t minor_id = 0;
4511 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4512 
4513 	major_id = nn->nfsd_name;
4514 	major_id_sz = strlen(nn->nfsd_name);
4515 	server_scope = nn->nfsd_name;
4516 	server_scope_sz = strlen(nn->nfsd_name);
4517 
4518 	if (nfsd4_encode_clientid4(xdr, &exid->clientid) != nfs_ok)
4519 		return nfserr_resource;
4520 	if (xdr_stream_encode_u32(xdr, exid->seqid) < 0)
4521 		return nfserr_resource;
4522 	if (xdr_stream_encode_u32(xdr, exid->flags) < 0)
4523 		return nfserr_resource;
4524 
4525 	if (xdr_stream_encode_u32(xdr, exid->spa_how) < 0)
4526 		return nfserr_resource;
4527 	switch (exid->spa_how) {
4528 	case SP4_NONE:
4529 		break;
4530 	case SP4_MACH_CRED:
4531 		/* spo_must_enforce bitmap: */
4532 		nfserr = nfsd4_encode_bitmap(xdr,
4533 					exid->spo_must_enforce[0],
4534 					exid->spo_must_enforce[1],
4535 					exid->spo_must_enforce[2]);
4536 		if (nfserr)
4537 			return nfserr;
4538 		/* spo_must_allow bitmap: */
4539 		nfserr = nfsd4_encode_bitmap(xdr,
4540 					exid->spo_must_allow[0],
4541 					exid->spo_must_allow[1],
4542 					exid->spo_must_allow[2]);
4543 		if (nfserr)
4544 			return nfserr;
4545 		break;
4546 	default:
4547 		WARN_ON_ONCE(1);
4548 	}
4549 
4550 	p = xdr_reserve_space(xdr,
4551 		8 /* so_minor_id */ +
4552 		4 /* so_major_id.len */ +
4553 		(XDR_QUADLEN(major_id_sz) * 4) +
4554 		4 /* eir_server_scope.len */ +
4555 		(XDR_QUADLEN(server_scope_sz) * 4) +
4556 		4 /* eir_server_impl_id.count (0) */);
4557 	if (!p)
4558 		return nfserr_resource;
4559 
4560 	/* The server_owner struct */
4561 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
4562 	/* major id */
4563 	p = xdr_encode_opaque(p, major_id, major_id_sz);
4564 
4565 	/* Server scope */
4566 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
4567 
4568 	/* Implementation id */
4569 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
4570 	return 0;
4571 }
4572 
4573 static __be32
4574 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4575 			    union nfsd4_op_u *u)
4576 {
4577 	struct nfsd4_create_session *sess = &u->create_session;
4578 	struct xdr_stream *xdr = resp->xdr;
4579 	__be32 *p;
4580 
4581 	p = xdr_reserve_space(xdr, 24);
4582 	if (!p)
4583 		return nfserr_resource;
4584 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
4585 					NFS4_MAX_SESSIONID_LEN);
4586 	*p++ = cpu_to_be32(sess->seqid);
4587 	*p++ = cpu_to_be32(sess->flags);
4588 
4589 	p = xdr_reserve_space(xdr, 28);
4590 	if (!p)
4591 		return nfserr_resource;
4592 	*p++ = cpu_to_be32(0); /* headerpadsz */
4593 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
4594 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
4595 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
4596 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4597 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4598 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4599 
4600 	if (sess->fore_channel.nr_rdma_attrs) {
4601 		p = xdr_reserve_space(xdr, 4);
4602 		if (!p)
4603 			return nfserr_resource;
4604 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4605 	}
4606 
4607 	p = xdr_reserve_space(xdr, 28);
4608 	if (!p)
4609 		return nfserr_resource;
4610 	*p++ = cpu_to_be32(0); /* headerpadsz */
4611 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4612 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4613 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4614 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4615 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4616 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4617 
4618 	if (sess->back_channel.nr_rdma_attrs) {
4619 		p = xdr_reserve_space(xdr, 4);
4620 		if (!p)
4621 			return nfserr_resource;
4622 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4623 	}
4624 	return 0;
4625 }
4626 
4627 static __be32
4628 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4629 		      union nfsd4_op_u *u)
4630 {
4631 	struct nfsd4_sequence *seq = &u->sequence;
4632 	struct xdr_stream *xdr = resp->xdr;
4633 	__be32 *p;
4634 
4635 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4636 	if (!p)
4637 		return nfserr_resource;
4638 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4639 					NFS4_MAX_SESSIONID_LEN);
4640 	*p++ = cpu_to_be32(seq->seqid);
4641 	*p++ = cpu_to_be32(seq->slotid);
4642 	/* Note slotid's are numbered from zero: */
4643 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4644 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4645 	*p++ = cpu_to_be32(seq->status_flags);
4646 
4647 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4648 	return 0;
4649 }
4650 
4651 static __be32
4652 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4653 			  union nfsd4_op_u *u)
4654 {
4655 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
4656 	struct xdr_stream *xdr = resp->xdr;
4657 	struct nfsd4_test_stateid_id *stateid, *next;
4658 	__be32 *p;
4659 
4660 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4661 	if (!p)
4662 		return nfserr_resource;
4663 	*p++ = htonl(test_stateid->ts_num_ids);
4664 
4665 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4666 		*p++ = stateid->ts_id_status;
4667 	}
4668 
4669 	return 0;
4670 }
4671 
4672 #ifdef CONFIG_NFSD_PNFS
4673 static __be32
4674 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4675 		union nfsd4_op_u *u)
4676 {
4677 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
4678 	struct xdr_stream *xdr = resp->xdr;
4679 	const struct nfsd4_layout_ops *ops;
4680 	u32 starting_len = xdr->buf->len, needed_len;
4681 	__be32 *p;
4682 
4683 	p = xdr_reserve_space(xdr, 4);
4684 	if (!p)
4685 		return nfserr_resource;
4686 
4687 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4688 
4689 	ops = nfsd4_layout_ops[gdev->gd_layout_type];
4690 	nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4691 	if (nfserr) {
4692 		/*
4693 		 * We don't bother to burden the layout drivers with
4694 		 * enforcing gd_maxcount, just tell the client to
4695 		 * come back with a bigger buffer if it's not enough.
4696 		 */
4697 		if (xdr->buf->len + 4 > gdev->gd_maxcount)
4698 			goto toosmall;
4699 		return nfserr;
4700 	}
4701 
4702 	if (gdev->gd_notify_types) {
4703 		p = xdr_reserve_space(xdr, 4 + 4);
4704 		if (!p)
4705 			return nfserr_resource;
4706 		*p++ = cpu_to_be32(1);			/* bitmap length */
4707 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4708 	} else {
4709 		p = xdr_reserve_space(xdr, 4);
4710 		if (!p)
4711 			return nfserr_resource;
4712 		*p++ = 0;
4713 	}
4714 
4715 	return 0;
4716 toosmall:
4717 	dprintk("%s: maxcount too small\n", __func__);
4718 	needed_len = xdr->buf->len + 4 /* notifications */;
4719 	xdr_truncate_encode(xdr, starting_len);
4720 	p = xdr_reserve_space(xdr, 4);
4721 	if (!p)
4722 		return nfserr_resource;
4723 	*p++ = cpu_to_be32(needed_len);
4724 	return nfserr_toosmall;
4725 }
4726 
4727 static __be32
4728 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4729 		union nfsd4_op_u *u)
4730 {
4731 	struct nfsd4_layoutget *lgp = &u->layoutget;
4732 	struct xdr_stream *xdr = resp->xdr;
4733 	const struct nfsd4_layout_ops *ops;
4734 	__be32 *p;
4735 
4736 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4737 	if (!p)
4738 		return nfserr_resource;
4739 
4740 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4741 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4742 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4743 				    sizeof(stateid_opaque_t));
4744 
4745 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4746 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4747 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4748 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4749 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4750 
4751 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4752 	return ops->encode_layoutget(xdr, lgp);
4753 }
4754 
4755 static __be32
4756 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4757 			  union nfsd4_op_u *u)
4758 {
4759 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
4760 	struct xdr_stream *xdr = resp->xdr;
4761 	__be32 *p;
4762 
4763 	p = xdr_reserve_space(xdr, 4);
4764 	if (!p)
4765 		return nfserr_resource;
4766 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4767 	if (lcp->lc_size_chg) {
4768 		p = xdr_reserve_space(xdr, 8);
4769 		if (!p)
4770 			return nfserr_resource;
4771 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4772 	}
4773 
4774 	return 0;
4775 }
4776 
4777 static __be32
4778 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4779 		union nfsd4_op_u *u)
4780 {
4781 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
4782 	struct xdr_stream *xdr = resp->xdr;
4783 	__be32 *p;
4784 
4785 	p = xdr_reserve_space(xdr, 4);
4786 	if (!p)
4787 		return nfserr_resource;
4788 	*p++ = cpu_to_be32(lrp->lrs_present);
4789 	if (lrp->lrs_present)
4790 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4791 	return 0;
4792 }
4793 #endif /* CONFIG_NFSD_PNFS */
4794 
4795 static __be32
4796 nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
4797 		struct nfsd42_write_res *write, bool sync)
4798 {
4799 	__be32 *p;
4800 	p = xdr_reserve_space(resp->xdr, 4);
4801 	if (!p)
4802 		return nfserr_resource;
4803 
4804 	if (sync)
4805 		*p++ = cpu_to_be32(0);
4806 	else {
4807 		__be32 nfserr;
4808 		*p++ = cpu_to_be32(1);
4809 		nfserr = nfsd4_encode_stateid(resp->xdr, &write->cb_stateid);
4810 		if (nfserr)
4811 			return nfserr;
4812 	}
4813 	p = xdr_reserve_space(resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
4814 	if (!p)
4815 		return nfserr_resource;
4816 
4817 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4818 	*p++ = cpu_to_be32(write->wr_stable_how);
4819 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4820 				    NFS4_VERIFIER_SIZE);
4821 	return nfs_ok;
4822 }
4823 
4824 static __be32
4825 nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
4826 {
4827 	struct xdr_stream *xdr = resp->xdr;
4828 	struct nfs42_netaddr *addr;
4829 	__be32 *p;
4830 
4831 	p = xdr_reserve_space(xdr, 4);
4832 	*p++ = cpu_to_be32(ns->nl4_type);
4833 
4834 	switch (ns->nl4_type) {
4835 	case NL4_NETADDR:
4836 		addr = &ns->u.nl4_addr;
4837 
4838 		/* netid_len, netid, uaddr_len, uaddr (port included
4839 		 * in RPCBIND_MAXUADDRLEN)
4840 		 */
4841 		p = xdr_reserve_space(xdr,
4842 			4 /* netid len */ +
4843 			(XDR_QUADLEN(addr->netid_len) * 4) +
4844 			4 /* uaddr len */ +
4845 			(XDR_QUADLEN(addr->addr_len) * 4));
4846 		if (!p)
4847 			return nfserr_resource;
4848 
4849 		*p++ = cpu_to_be32(addr->netid_len);
4850 		p = xdr_encode_opaque_fixed(p, addr->netid,
4851 					    addr->netid_len);
4852 		*p++ = cpu_to_be32(addr->addr_len);
4853 		p = xdr_encode_opaque_fixed(p, addr->addr,
4854 					addr->addr_len);
4855 		break;
4856 	default:
4857 		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
4858 		return nfserr_inval;
4859 	}
4860 
4861 	return 0;
4862 }
4863 
4864 static __be32
4865 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4866 		  union nfsd4_op_u *u)
4867 {
4868 	struct nfsd4_copy *copy = &u->copy;
4869 	__be32 *p;
4870 
4871 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
4872 					 nfsd4_copy_is_sync(copy));
4873 	if (nfserr)
4874 		return nfserr;
4875 
4876 	p = xdr_reserve_space(resp->xdr, 4 + 4);
4877 	*p++ = xdr_one; /* cr_consecutive */
4878 	*p = nfsd4_copy_is_sync(copy) ? xdr_one : xdr_zero;
4879 	return 0;
4880 }
4881 
4882 static __be32
4883 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
4884 			    union nfsd4_op_u *u)
4885 {
4886 	struct nfsd4_offload_status *os = &u->offload_status;
4887 	struct xdr_stream *xdr = resp->xdr;
4888 	__be32 *p;
4889 
4890 	p = xdr_reserve_space(xdr, 8 + 4);
4891 	if (!p)
4892 		return nfserr_resource;
4893 	p = xdr_encode_hyper(p, os->count);
4894 	*p++ = cpu_to_be32(0);
4895 	return nfserr;
4896 }
4897 
4898 static __be32
4899 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
4900 			    struct nfsd4_read *read)
4901 {
4902 	bool splice_ok = test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags);
4903 	struct file *file = read->rd_nf->nf_file;
4904 	struct xdr_stream *xdr = resp->xdr;
4905 	unsigned long maxcount;
4906 	__be32 nfserr, *p;
4907 
4908 	/* Content type, offset, byte count */
4909 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
4910 	if (!p)
4911 		return nfserr_io;
4912 	if (resp->xdr->buf->page_len && splice_ok) {
4913 		WARN_ON_ONCE(splice_ok);
4914 		return nfserr_serverfault;
4915 	}
4916 
4917 	maxcount = min_t(unsigned long, read->rd_length,
4918 			 (xdr->buf->buflen - xdr->buf->len));
4919 
4920 	if (file->f_op->splice_read && splice_ok)
4921 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4922 	else
4923 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4924 	if (nfserr)
4925 		return nfserr;
4926 
4927 	*p++ = cpu_to_be32(NFS4_CONTENT_DATA);
4928 	p = xdr_encode_hyper(p, read->rd_offset);
4929 	*p = cpu_to_be32(read->rd_length);
4930 
4931 	return nfs_ok;
4932 }
4933 
4934 static __be32
4935 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
4936 		       union nfsd4_op_u *u)
4937 {
4938 	struct nfsd4_read *read = &u->read;
4939 	struct file *file = read->rd_nf->nf_file;
4940 	struct xdr_stream *xdr = resp->xdr;
4941 	int starting_len = xdr->buf->len;
4942 	u32 segments = 0;
4943 	__be32 *p;
4944 
4945 	if (nfserr)
4946 		return nfserr;
4947 
4948 	/* eof flag, segment count */
4949 	p = xdr_reserve_space(xdr, 4 + 4);
4950 	if (!p)
4951 		return nfserr_io;
4952 	xdr_commit_encode(xdr);
4953 
4954 	read->rd_eof = read->rd_offset >= i_size_read(file_inode(file));
4955 	if (read->rd_eof)
4956 		goto out;
4957 
4958 	nfserr = nfsd4_encode_read_plus_data(resp, read);
4959 	if (nfserr) {
4960 		xdr_truncate_encode(xdr, starting_len);
4961 		return nfserr;
4962 	}
4963 
4964 	segments++;
4965 
4966 out:
4967 	p = xdr_encode_bool(p, read->rd_eof);
4968 	*p = cpu_to_be32(segments);
4969 	return nfserr;
4970 }
4971 
4972 static __be32
4973 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
4974 			 union nfsd4_op_u *u)
4975 {
4976 	struct nfsd4_copy_notify *cn = &u->copy_notify;
4977 	struct xdr_stream *xdr = resp->xdr;
4978 	__be32 *p;
4979 
4980 	if (nfserr)
4981 		return nfserr;
4982 
4983 	/* 8 sec, 4 nsec */
4984 	p = xdr_reserve_space(xdr, 12);
4985 	if (!p)
4986 		return nfserr_resource;
4987 
4988 	/* cnr_lease_time */
4989 	p = xdr_encode_hyper(p, cn->cpn_sec);
4990 	*p++ = cpu_to_be32(cn->cpn_nsec);
4991 
4992 	/* cnr_stateid */
4993 	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
4994 	if (nfserr)
4995 		return nfserr;
4996 
4997 	/* cnr_src.nl_nsvr */
4998 	p = xdr_reserve_space(xdr, 4);
4999 	if (!p)
5000 		return nfserr_resource;
5001 
5002 	*p++ = cpu_to_be32(1);
5003 
5004 	nfserr = nfsd42_encode_nl4_server(resp, cn->cpn_src);
5005 	return nfserr;
5006 }
5007 
5008 static __be32
5009 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
5010 		  union nfsd4_op_u *u)
5011 {
5012 	struct nfsd4_seek *seek = &u->seek;
5013 	__be32 *p;
5014 
5015 	p = xdr_reserve_space(resp->xdr, 4 + 8);
5016 	*p++ = cpu_to_be32(seek->seek_eof);
5017 	p = xdr_encode_hyper(p, seek->seek_pos);
5018 
5019 	return 0;
5020 }
5021 
5022 static __be32
5023 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr,
5024 		  union nfsd4_op_u *p)
5025 {
5026 	return nfserr;
5027 }
5028 
5029 /*
5030  * Encode kmalloc-ed buffer in to XDR stream.
5031  */
5032 static __be32
5033 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
5034 {
5035 	u32 cplen;
5036 	__be32 *p;
5037 
5038 	cplen = min_t(unsigned long, buflen,
5039 		      ((void *)xdr->end - (void *)xdr->p));
5040 	p = xdr_reserve_space(xdr, cplen);
5041 	if (!p)
5042 		return nfserr_resource;
5043 
5044 	memcpy(p, buf, cplen);
5045 	buf += cplen;
5046 	buflen -= cplen;
5047 
5048 	while (buflen) {
5049 		cplen = min_t(u32, buflen, PAGE_SIZE);
5050 		p = xdr_reserve_space(xdr, cplen);
5051 		if (!p)
5052 			return nfserr_resource;
5053 
5054 		memcpy(p, buf, cplen);
5055 
5056 		if (cplen < PAGE_SIZE) {
5057 			/*
5058 			 * We're done, with a length that wasn't page
5059 			 * aligned, so possibly not word aligned. Pad
5060 			 * any trailing bytes with 0.
5061 			 */
5062 			xdr_encode_opaque_fixed(p, NULL, cplen);
5063 			break;
5064 		}
5065 
5066 		buflen -= PAGE_SIZE;
5067 		buf += PAGE_SIZE;
5068 	}
5069 
5070 	return 0;
5071 }
5072 
5073 static __be32
5074 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5075 		      union nfsd4_op_u *u)
5076 {
5077 	struct nfsd4_getxattr *getxattr = &u->getxattr;
5078 	struct xdr_stream *xdr = resp->xdr;
5079 	__be32 *p, err;
5080 
5081 	p = xdr_reserve_space(xdr, 4);
5082 	if (!p)
5083 		return nfserr_resource;
5084 
5085 	*p = cpu_to_be32(getxattr->getxa_len);
5086 
5087 	if (getxattr->getxa_len == 0)
5088 		return 0;
5089 
5090 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
5091 				    getxattr->getxa_len);
5092 
5093 	kvfree(getxattr->getxa_buf);
5094 
5095 	return err;
5096 }
5097 
5098 static __be32
5099 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5100 		      union nfsd4_op_u *u)
5101 {
5102 	struct nfsd4_setxattr *setxattr = &u->setxattr;
5103 	struct xdr_stream *xdr = resp->xdr;
5104 
5105 	return nfsd4_encode_change_info4(xdr, &setxattr->setxa_cinfo);
5106 }
5107 
5108 /*
5109  * See if there are cookie values that can be rejected outright.
5110  */
5111 static __be32
5112 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5113 				u32 *offsetp)
5114 {
5115 	u64 cookie = listxattrs->lsxa_cookie;
5116 
5117 	/*
5118 	 * If the cookie is larger than the maximum number we can fit
5119 	 * in either the buffer we just got back from vfs_listxattr, or,
5120 	 * XDR-encoded, in the return buffer, it's invalid.
5121 	 */
5122 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5123 		return nfserr_badcookie;
5124 
5125 	if (cookie > (listxattrs->lsxa_maxcount /
5126 		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
5127 		return nfserr_badcookie;
5128 
5129 	*offsetp = (u32)cookie;
5130 	return 0;
5131 }
5132 
5133 static __be32
5134 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5135 			union nfsd4_op_u *u)
5136 {
5137 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
5138 	struct xdr_stream *xdr = resp->xdr;
5139 	u32 cookie_offset, count_offset, eof;
5140 	u32 left, xdrleft, slen, count;
5141 	u32 xdrlen, offset;
5142 	u64 cookie;
5143 	char *sp;
5144 	__be32 status, tmp;
5145 	__be32 *p;
5146 	u32 nuser;
5147 
5148 	eof = 1;
5149 
5150 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5151 	if (status)
5152 		goto out;
5153 
5154 	/*
5155 	 * Reserve space for the cookie and the name array count. Record
5156 	 * the offsets to save them later.
5157 	 */
5158 	cookie_offset = xdr->buf->len;
5159 	count_offset = cookie_offset + 8;
5160 	p = xdr_reserve_space(xdr, 12);
5161 	if (!p) {
5162 		status = nfserr_resource;
5163 		goto out;
5164 	}
5165 
5166 	count = 0;
5167 	left = listxattrs->lsxa_len;
5168 	sp = listxattrs->lsxa_buf;
5169 	nuser = 0;
5170 
5171 	xdrleft = listxattrs->lsxa_maxcount;
5172 
5173 	while (left > 0 && xdrleft > 0) {
5174 		slen = strlen(sp);
5175 
5176 		/*
5177 		 * Check if this is a "user." attribute, skip it if not.
5178 		 */
5179 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5180 			goto contloop;
5181 
5182 		slen -= XATTR_USER_PREFIX_LEN;
5183 		xdrlen = 4 + ((slen + 3) & ~3);
5184 		if (xdrlen > xdrleft) {
5185 			if (count == 0) {
5186 				/*
5187 				 * Can't even fit the first attribute name.
5188 				 */
5189 				status = nfserr_toosmall;
5190 				goto out;
5191 			}
5192 			eof = 0;
5193 			goto wreof;
5194 		}
5195 
5196 		left -= XATTR_USER_PREFIX_LEN;
5197 		sp += XATTR_USER_PREFIX_LEN;
5198 		if (nuser++ < offset)
5199 			goto contloop;
5200 
5201 
5202 		p = xdr_reserve_space(xdr, xdrlen);
5203 		if (!p) {
5204 			status = nfserr_resource;
5205 			goto out;
5206 		}
5207 
5208 		xdr_encode_opaque(p, sp, slen);
5209 
5210 		xdrleft -= xdrlen;
5211 		count++;
5212 contloop:
5213 		sp += slen + 1;
5214 		left -= slen + 1;
5215 	}
5216 
5217 	/*
5218 	 * If there were user attributes to copy, but we didn't copy
5219 	 * any, the offset was too large (e.g. the cookie was invalid).
5220 	 */
5221 	if (nuser > 0 && count == 0) {
5222 		status = nfserr_badcookie;
5223 		goto out;
5224 	}
5225 
5226 wreof:
5227 	p = xdr_reserve_space(xdr, 4);
5228 	if (!p) {
5229 		status = nfserr_resource;
5230 		goto out;
5231 	}
5232 	*p = cpu_to_be32(eof);
5233 
5234 	cookie = offset + count;
5235 
5236 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
5237 	tmp = cpu_to_be32(count);
5238 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5239 out:
5240 	if (listxattrs->lsxa_len)
5241 		kvfree(listxattrs->lsxa_buf);
5242 	return status;
5243 }
5244 
5245 static __be32
5246 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5247 			 union nfsd4_op_u *u)
5248 {
5249 	struct nfsd4_removexattr *removexattr = &u->removexattr;
5250 	struct xdr_stream *xdr = resp->xdr;
5251 
5252 	return nfsd4_encode_change_info4(xdr, &removexattr->rmxa_cinfo);
5253 }
5254 
5255 typedef __be32(*nfsd4_enc)(struct nfsd4_compoundres *, __be32, union nfsd4_op_u *u);
5256 
5257 /*
5258  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5259  * since we don't need to filter out obsolete ops as this is
5260  * done in the decoding phase.
5261  */
5262 static const nfsd4_enc nfsd4_enc_ops[] = {
5263 	[OP_ACCESS]		= nfsd4_encode_access,
5264 	[OP_CLOSE]		= nfsd4_encode_close,
5265 	[OP_COMMIT]		= nfsd4_encode_commit,
5266 	[OP_CREATE]		= nfsd4_encode_create,
5267 	[OP_DELEGPURGE]		= nfsd4_encode_noop,
5268 	[OP_DELEGRETURN]	= nfsd4_encode_noop,
5269 	[OP_GETATTR]		= nfsd4_encode_getattr,
5270 	[OP_GETFH]		= nfsd4_encode_getfh,
5271 	[OP_LINK]		= nfsd4_encode_link,
5272 	[OP_LOCK]		= nfsd4_encode_lock,
5273 	[OP_LOCKT]		= nfsd4_encode_lockt,
5274 	[OP_LOCKU]		= nfsd4_encode_locku,
5275 	[OP_LOOKUP]		= nfsd4_encode_noop,
5276 	[OP_LOOKUPP]		= nfsd4_encode_noop,
5277 	[OP_NVERIFY]		= nfsd4_encode_noop,
5278 	[OP_OPEN]		= nfsd4_encode_open,
5279 	[OP_OPENATTR]		= nfsd4_encode_noop,
5280 	[OP_OPEN_CONFIRM]	= nfsd4_encode_open_confirm,
5281 	[OP_OPEN_DOWNGRADE]	= nfsd4_encode_open_downgrade,
5282 	[OP_PUTFH]		= nfsd4_encode_noop,
5283 	[OP_PUTPUBFH]		= nfsd4_encode_noop,
5284 	[OP_PUTROOTFH]		= nfsd4_encode_noop,
5285 	[OP_READ]		= nfsd4_encode_read,
5286 	[OP_READDIR]		= nfsd4_encode_readdir,
5287 	[OP_READLINK]		= nfsd4_encode_readlink,
5288 	[OP_REMOVE]		= nfsd4_encode_remove,
5289 	[OP_RENAME]		= nfsd4_encode_rename,
5290 	[OP_RENEW]		= nfsd4_encode_noop,
5291 	[OP_RESTOREFH]		= nfsd4_encode_noop,
5292 	[OP_SAVEFH]		= nfsd4_encode_noop,
5293 	[OP_SECINFO]		= nfsd4_encode_secinfo,
5294 	[OP_SETATTR]		= nfsd4_encode_setattr,
5295 	[OP_SETCLIENTID]	= nfsd4_encode_setclientid,
5296 	[OP_SETCLIENTID_CONFIRM] = nfsd4_encode_noop,
5297 	[OP_VERIFY]		= nfsd4_encode_noop,
5298 	[OP_WRITE]		= nfsd4_encode_write,
5299 	[OP_RELEASE_LOCKOWNER]	= nfsd4_encode_noop,
5300 
5301 	/* NFSv4.1 operations */
5302 	[OP_BACKCHANNEL_CTL]	= nfsd4_encode_noop,
5303 	[OP_BIND_CONN_TO_SESSION] = nfsd4_encode_bind_conn_to_session,
5304 	[OP_EXCHANGE_ID]	= nfsd4_encode_exchange_id,
5305 	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
5306 	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
5307 	[OP_FREE_STATEID]	= nfsd4_encode_noop,
5308 	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_noop,
5309 #ifdef CONFIG_NFSD_PNFS
5310 	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
5311 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5312 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_layoutcommit,
5313 	[OP_LAYOUTGET]		= nfsd4_encode_layoutget,
5314 	[OP_LAYOUTRETURN]	= nfsd4_encode_layoutreturn,
5315 #else
5316 	[OP_GETDEVICEINFO]	= nfsd4_encode_noop,
5317 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5318 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_noop,
5319 	[OP_LAYOUTGET]		= nfsd4_encode_noop,
5320 	[OP_LAYOUTRETURN]	= nfsd4_encode_noop,
5321 #endif
5322 	[OP_SECINFO_NO_NAME]	= nfsd4_encode_secinfo_no_name,
5323 	[OP_SEQUENCE]		= nfsd4_encode_sequence,
5324 	[OP_SET_SSV]		= nfsd4_encode_noop,
5325 	[OP_TEST_STATEID]	= nfsd4_encode_test_stateid,
5326 	[OP_WANT_DELEGATION]	= nfsd4_encode_noop,
5327 	[OP_DESTROY_CLIENTID]	= nfsd4_encode_noop,
5328 	[OP_RECLAIM_COMPLETE]	= nfsd4_encode_noop,
5329 
5330 	/* NFSv4.2 operations */
5331 	[OP_ALLOCATE]		= nfsd4_encode_noop,
5332 	[OP_COPY]		= nfsd4_encode_copy,
5333 	[OP_COPY_NOTIFY]	= nfsd4_encode_copy_notify,
5334 	[OP_DEALLOCATE]		= nfsd4_encode_noop,
5335 	[OP_IO_ADVISE]		= nfsd4_encode_noop,
5336 	[OP_LAYOUTERROR]	= nfsd4_encode_noop,
5337 	[OP_LAYOUTSTATS]	= nfsd4_encode_noop,
5338 	[OP_OFFLOAD_CANCEL]	= nfsd4_encode_noop,
5339 	[OP_OFFLOAD_STATUS]	= nfsd4_encode_offload_status,
5340 	[OP_READ_PLUS]		= nfsd4_encode_read_plus,
5341 	[OP_SEEK]		= nfsd4_encode_seek,
5342 	[OP_WRITE_SAME]		= nfsd4_encode_noop,
5343 	[OP_CLONE]		= nfsd4_encode_noop,
5344 
5345 	/* RFC 8276 extended atributes operations */
5346 	[OP_GETXATTR]		= nfsd4_encode_getxattr,
5347 	[OP_SETXATTR]		= nfsd4_encode_setxattr,
5348 	[OP_LISTXATTRS]		= nfsd4_encode_listxattrs,
5349 	[OP_REMOVEXATTR]	= nfsd4_encode_removexattr,
5350 };
5351 
5352 /*
5353  * Calculate whether we still have space to encode repsize bytes.
5354  * There are two considerations:
5355  *     - For NFS versions >=4.1, the size of the reply must stay within
5356  *       session limits
5357  *     - For all NFS versions, we must stay within limited preallocated
5358  *       buffer space.
5359  *
5360  * This is called before the operation is processed, so can only provide
5361  * an upper estimate.  For some nonidempotent operations (such as
5362  * getattr), it's not necessarily a problem if that estimate is wrong,
5363  * as we can fail it after processing without significant side effects.
5364  */
5365 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5366 {
5367 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5368 	struct nfsd4_slot *slot = resp->cstate.slot;
5369 
5370 	if (buf->len + respsize <= buf->buflen)
5371 		return nfs_ok;
5372 	if (!nfsd4_has_session(&resp->cstate))
5373 		return nfserr_resource;
5374 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5375 		WARN_ON_ONCE(1);
5376 		return nfserr_rep_too_big_to_cache;
5377 	}
5378 	return nfserr_rep_too_big;
5379 }
5380 
5381 void
5382 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5383 {
5384 	struct xdr_stream *xdr = resp->xdr;
5385 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5386 	struct svc_rqst *rqstp = resp->rqstp;
5387 	const struct nfsd4_operation *opdesc = op->opdesc;
5388 	int post_err_offset;
5389 	nfsd4_enc encoder;
5390 	__be32 *p;
5391 
5392 	p = xdr_reserve_space(xdr, 8);
5393 	if (!p)
5394 		goto release;
5395 	*p++ = cpu_to_be32(op->opnum);
5396 	post_err_offset = xdr->buf->len;
5397 
5398 	if (op->opnum == OP_ILLEGAL)
5399 		goto status;
5400 	if (op->status && opdesc &&
5401 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5402 		goto status;
5403 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5404 	       !nfsd4_enc_ops[op->opnum]);
5405 	encoder = nfsd4_enc_ops[op->opnum];
5406 	op->status = encoder(resp, op->status, &op->u);
5407 	if (op->status)
5408 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5409 	xdr_commit_encode(xdr);
5410 
5411 	/* nfsd4_check_resp_size guarantees enough room for error status */
5412 	if (!op->status) {
5413 		int space_needed = 0;
5414 		if (!nfsd4_last_compound_op(rqstp))
5415 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5416 		op->status = nfsd4_check_resp_size(resp, space_needed);
5417 	}
5418 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5419 		struct nfsd4_slot *slot = resp->cstate.slot;
5420 
5421 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5422 			op->status = nfserr_rep_too_big_to_cache;
5423 		else
5424 			op->status = nfserr_rep_too_big;
5425 	}
5426 	if (op->status == nfserr_resource ||
5427 	    op->status == nfserr_rep_too_big ||
5428 	    op->status == nfserr_rep_too_big_to_cache) {
5429 		/*
5430 		 * The operation may have already been encoded or
5431 		 * partially encoded.  No op returns anything additional
5432 		 * in the case of one of these three errors, so we can
5433 		 * just truncate back to after the status.  But it's a
5434 		 * bug if we had to do this on a non-idempotent op:
5435 		 */
5436 		warn_on_nonidempotent_op(op);
5437 		xdr_truncate_encode(xdr, post_err_offset);
5438 	}
5439 	if (so) {
5440 		int len = xdr->buf->len - post_err_offset;
5441 
5442 		so->so_replay.rp_status = op->status;
5443 		so->so_replay.rp_buflen = len;
5444 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5445 						so->so_replay.rp_buf, len);
5446 	}
5447 status:
5448 	*p = op->status;
5449 release:
5450 	if (opdesc && opdesc->op_release)
5451 		opdesc->op_release(&op->u);
5452 
5453 	/*
5454 	 * Account for pages consumed while encoding this operation.
5455 	 * The xdr_stream primitives don't manage rq_next_page.
5456 	 */
5457 	rqstp->rq_next_page = xdr->page_ptr + 1;
5458 }
5459 
5460 /*
5461  * Encode the reply stored in the stateowner reply cache
5462  *
5463  * XDR note: do not encode rp->rp_buflen: the buffer contains the
5464  * previously sent already encoded operation.
5465  */
5466 void
5467 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5468 {
5469 	__be32 *p;
5470 	struct nfs4_replay *rp = op->replay;
5471 
5472 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
5473 	if (!p) {
5474 		WARN_ON_ONCE(1);
5475 		return;
5476 	}
5477 	*p++ = cpu_to_be32(op->opnum);
5478 	*p++ = rp->rp_status;  /* already xdr'ed */
5479 
5480 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
5481 }
5482 
5483 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5484 {
5485 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5486 
5487 	if (args->ops != args->iops) {
5488 		vfree(args->ops);
5489 		args->ops = args->iops;
5490 	}
5491 	while (args->to_free) {
5492 		struct svcxdr_tmpbuf *tb = args->to_free;
5493 		args->to_free = tb->next;
5494 		kfree(tb);
5495 	}
5496 }
5497 
5498 bool
5499 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5500 {
5501 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5502 
5503 	/* svcxdr_tmp_alloc */
5504 	args->to_free = NULL;
5505 
5506 	args->xdr = xdr;
5507 	args->ops = args->iops;
5508 	args->rqstp = rqstp;
5509 
5510 	return nfsd4_decode_compound(args);
5511 }
5512 
5513 bool
5514 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5515 {
5516 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5517 	__be32 *p;
5518 
5519 	/*
5520 	 * Send buffer space for the following items is reserved
5521 	 * at the top of nfsd4_proc_compound().
5522 	 */
5523 	p = resp->statusp;
5524 
5525 	*p++ = resp->cstate.status;
5526 	*p++ = htonl(resp->taglen);
5527 	memcpy(p, resp->tag, resp->taglen);
5528 	p += XDR_QUADLEN(resp->taglen);
5529 	*p++ = htonl(resp->opcnt);
5530 
5531 	nfsd4_sequence_done(resp);
5532 	return true;
5533 }
5534