xref: /linux/fs/nfsd/nfs4xdr.c (revision 90d32e92011eaae8e70a9169b4e7acf4ca8f9d3a)
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 static __be32
1736 nfsd4_decode_get_dir_delegation(struct nfsd4_compoundargs *argp,
1737 		union nfsd4_op_u *u)
1738 {
1739 	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
1740 	__be32 status;
1741 
1742 	memset(gdd, 0, sizeof(*gdd));
1743 
1744 	if (xdr_stream_decode_bool(argp->xdr, &gdd->gdda_signal_deleg_avail) < 0)
1745 		return nfserr_bad_xdr;
1746 	status = nfsd4_decode_bitmap4(argp, gdd->gdda_notification_types,
1747 				      ARRAY_SIZE(gdd->gdda_notification_types));
1748 	if (status)
1749 		return status;
1750 	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_child_attr_delay);
1751 	if (status)
1752 		return status;
1753 	status = nfsd4_decode_nfstime4(argp, &gdd->gdda_dir_attr_delay);
1754 	if (status)
1755 		return status;
1756 	status = nfsd4_decode_bitmap4(argp, gdd->gdda_child_attributes,
1757 					ARRAY_SIZE(gdd->gdda_child_attributes));
1758 	if (status)
1759 		return status;
1760 	return nfsd4_decode_bitmap4(argp, gdd->gdda_dir_attributes,
1761 					ARRAY_SIZE(gdd->gdda_dir_attributes));
1762 }
1763 
1764 #ifdef CONFIG_NFSD_PNFS
1765 static __be32
1766 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1767 		union nfsd4_op_u *u)
1768 {
1769 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
1770 	__be32 status;
1771 
1772 	memset(gdev, 0, sizeof(*gdev));
1773 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1774 	if (status)
1775 		return status;
1776 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1777 		return nfserr_bad_xdr;
1778 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1779 		return nfserr_bad_xdr;
1780 	if (xdr_stream_decode_uint32_array(argp->xdr,
1781 					   &gdev->gd_notify_types, 1) < 0)
1782 		return nfserr_bad_xdr;
1783 
1784 	return nfs_ok;
1785 }
1786 
1787 static __be32
1788 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1789 			  union nfsd4_op_u *u)
1790 {
1791 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
1792 	__be32 *p, status;
1793 
1794 	memset(lcp, 0, sizeof(*lcp));
1795 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1796 		return nfserr_bad_xdr;
1797 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1798 		return nfserr_bad_xdr;
1799 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1800 		return nfserr_bad_xdr;
1801 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1802 	if (status)
1803 		return status;
1804 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1805 		return nfserr_bad_xdr;
1806 	if (lcp->lc_newoffset) {
1807 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1808 			return nfserr_bad_xdr;
1809 	} else
1810 		lcp->lc_last_wr = 0;
1811 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1812 	if (!p)
1813 		return nfserr_bad_xdr;
1814 	if (xdr_item_is_present(p)) {
1815 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1816 		if (status)
1817 			return status;
1818 	} else {
1819 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1820 	}
1821 	return nfsd4_decode_layoutupdate4(argp, lcp);
1822 }
1823 
1824 static __be32
1825 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1826 		union nfsd4_op_u *u)
1827 {
1828 	struct nfsd4_layoutget *lgp = &u->layoutget;
1829 	__be32 status;
1830 
1831 	memset(lgp, 0, sizeof(*lgp));
1832 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1833 		return nfserr_bad_xdr;
1834 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1835 		return nfserr_bad_xdr;
1836 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1837 		return nfserr_bad_xdr;
1838 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1839 		return nfserr_bad_xdr;
1840 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1841 		return nfserr_bad_xdr;
1842 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1843 		return nfserr_bad_xdr;
1844 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1845 	if (status)
1846 		return status;
1847 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1848 		return nfserr_bad_xdr;
1849 
1850 	return nfs_ok;
1851 }
1852 
1853 static __be32
1854 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1855 		union nfsd4_op_u *u)
1856 {
1857 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
1858 	memset(lrp, 0, sizeof(*lrp));
1859 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1860 		return nfserr_bad_xdr;
1861 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1862 		return nfserr_bad_xdr;
1863 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1864 		return nfserr_bad_xdr;
1865 	return nfsd4_decode_layoutreturn4(argp, lrp);
1866 }
1867 #endif /* CONFIG_NFSD_PNFS */
1868 
1869 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1870 					   union nfsd4_op_u *u)
1871 {
1872 	struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name;
1873 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1874 		return nfserr_bad_xdr;
1875 
1876 	sin->sin_exp = NULL;
1877 	return nfs_ok;
1878 }
1879 
1880 static __be32
1881 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1882 		      union nfsd4_op_u *u)
1883 {
1884 	struct nfsd4_sequence *seq = &u->sequence;
1885 	__be32 *p, status;
1886 
1887 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1888 	if (status)
1889 		return status;
1890 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1891 	if (!p)
1892 		return nfserr_bad_xdr;
1893 	seq->seqid = be32_to_cpup(p++);
1894 	seq->slotid = be32_to_cpup(p++);
1895 	seq->maxslots = be32_to_cpup(p++);
1896 	seq->cachethis = be32_to_cpup(p);
1897 
1898 	seq->status_flags = 0;
1899 	return nfs_ok;
1900 }
1901 
1902 static __be32
1903 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp,
1904 			  union nfsd4_op_u *u)
1905 {
1906 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
1907 	struct nfsd4_test_stateid_id *stateid;
1908 	__be32 status;
1909 	u32 i;
1910 
1911 	memset(test_stateid, 0, sizeof(*test_stateid));
1912 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1913 		return nfserr_bad_xdr;
1914 
1915 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1916 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1917 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1918 		if (!stateid)
1919 			return nfserr_jukebox;
1920 		INIT_LIST_HEAD(&stateid->ts_id_list);
1921 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1922 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1923 		if (status)
1924 			return status;
1925 	}
1926 
1927 	return nfs_ok;
1928 }
1929 
1930 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1931 					    union nfsd4_op_u *u)
1932 {
1933 	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
1934 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1935 }
1936 
1937 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1938 					    union nfsd4_op_u *u)
1939 {
1940 	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
1941 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1942 		return nfserr_bad_xdr;
1943 	return nfs_ok;
1944 }
1945 
1946 static __be32
1947 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1948 		       union nfsd4_op_u *u)
1949 {
1950 	struct nfsd4_fallocate *fallocate = &u->allocate;
1951 	__be32 status;
1952 
1953 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1954 	if (status)
1955 		return status;
1956 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1957 		return nfserr_bad_xdr;
1958 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1959 		return nfserr_bad_xdr;
1960 
1961 	return nfs_ok;
1962 }
1963 
1964 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1965 				      struct nl4_server *ns)
1966 {
1967 	struct nfs42_netaddr *naddr;
1968 	__be32 *p;
1969 
1970 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1971 		return nfserr_bad_xdr;
1972 
1973 	/* currently support for 1 inter-server source server */
1974 	switch (ns->nl4_type) {
1975 	case NL4_NETADDR:
1976 		naddr = &ns->u.nl4_addr;
1977 
1978 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1979 			return nfserr_bad_xdr;
1980 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1981 			return nfserr_bad_xdr;
1982 
1983 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1984 		if (!p)
1985 			return nfserr_bad_xdr;
1986 		memcpy(naddr->netid, p, naddr->netid_len);
1987 
1988 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1989 			return nfserr_bad_xdr;
1990 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1991 			return nfserr_bad_xdr;
1992 
1993 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1994 		if (!p)
1995 			return nfserr_bad_xdr;
1996 		memcpy(naddr->addr, p, naddr->addr_len);
1997 		break;
1998 	default:
1999 		return nfserr_bad_xdr;
2000 	}
2001 
2002 	return nfs_ok;
2003 }
2004 
2005 static __be32
2006 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2007 {
2008 	struct nfsd4_copy *copy = &u->copy;
2009 	u32 consecutive, i, count, sync;
2010 	struct nl4_server *ns_dummy;
2011 	__be32 status;
2012 
2013 	memset(copy, 0, sizeof(*copy));
2014 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
2015 	if (status)
2016 		return status;
2017 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
2018 	if (status)
2019 		return status;
2020 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
2021 		return nfserr_bad_xdr;
2022 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
2023 		return nfserr_bad_xdr;
2024 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
2025 		return nfserr_bad_xdr;
2026 	/* ca_consecutive: we always do consecutive copies */
2027 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
2028 		return nfserr_bad_xdr;
2029 	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
2030 		return nfserr_bad_xdr;
2031 	nfsd4_copy_set_sync(copy, sync);
2032 
2033 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
2034 		return nfserr_bad_xdr;
2035 	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
2036 	if (copy->cp_src == NULL)
2037 		return nfserr_jukebox;
2038 	if (count == 0) { /* intra-server copy */
2039 		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
2040 		return nfs_ok;
2041 	}
2042 
2043 	/* decode all the supplied server addresses but use only the first */
2044 	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
2045 	if (status)
2046 		return status;
2047 
2048 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
2049 	if (ns_dummy == NULL)
2050 		return nfserr_jukebox;
2051 	for (i = 0; i < count - 1; i++) {
2052 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
2053 		if (status) {
2054 			kfree(ns_dummy);
2055 			return status;
2056 		}
2057 	}
2058 	kfree(ns_dummy);
2059 
2060 	return nfs_ok;
2061 }
2062 
2063 static __be32
2064 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
2065 			 union nfsd4_op_u *u)
2066 {
2067 	struct nfsd4_copy_notify *cn = &u->copy_notify;
2068 	__be32 status;
2069 
2070 	memset(cn, 0, sizeof(*cn));
2071 	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
2072 	if (cn->cpn_src == NULL)
2073 		return nfserr_jukebox;
2074 	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
2075 	if (cn->cpn_dst == NULL)
2076 		return nfserr_jukebox;
2077 
2078 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
2079 	if (status)
2080 		return status;
2081 	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
2082 }
2083 
2084 static __be32
2085 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
2086 			    union nfsd4_op_u *u)
2087 {
2088 	struct nfsd4_offload_status *os = &u->offload_status;
2089 	os->count = 0;
2090 	os->status = 0;
2091 	return nfsd4_decode_stateid4(argp, &os->stateid);
2092 }
2093 
2094 static __be32
2095 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2096 {
2097 	struct nfsd4_seek *seek = &u->seek;
2098 	__be32 status;
2099 
2100 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
2101 	if (status)
2102 		return status;
2103 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
2104 		return nfserr_bad_xdr;
2105 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
2106 		return nfserr_bad_xdr;
2107 
2108 	seek->seek_eof = 0;
2109 	seek->seek_pos = 0;
2110 	return nfs_ok;
2111 }
2112 
2113 static __be32
2114 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2115 {
2116 	struct nfsd4_clone *clone = &u->clone;
2117 	__be32 status;
2118 
2119 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
2120 	if (status)
2121 		return status;
2122 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
2123 	if (status)
2124 		return status;
2125 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
2126 		return nfserr_bad_xdr;
2127 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
2128 		return nfserr_bad_xdr;
2129 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
2130 		return nfserr_bad_xdr;
2131 
2132 	return nfs_ok;
2133 }
2134 
2135 /*
2136  * XDR data that is more than PAGE_SIZE in size is normally part of a
2137  * read or write. However, the size of extended attributes is limited
2138  * by the maximum request size, and then further limited by the underlying
2139  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2140  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2141  * and we're not dealing with contiguous pages, we need to do some copying.
2142  */
2143 
2144 /*
2145  * Decode data into buffer.
2146  */
2147 static __be32
2148 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2149 		       char **bufp, u32 buflen)
2150 {
2151 	struct page **pages = xdr->pages;
2152 	struct kvec *head = xdr->head;
2153 	char *tmp, *dp;
2154 	u32 len;
2155 
2156 	if (buflen <= head->iov_len) {
2157 		/*
2158 		 * We're in luck, the head has enough space. Just return
2159 		 * the head, no need for copying.
2160 		 */
2161 		*bufp = head->iov_base;
2162 		return 0;
2163 	}
2164 
2165 	tmp = svcxdr_tmpalloc(argp, buflen);
2166 	if (tmp == NULL)
2167 		return nfserr_jukebox;
2168 
2169 	dp = tmp;
2170 	memcpy(dp, head->iov_base, head->iov_len);
2171 	buflen -= head->iov_len;
2172 	dp += head->iov_len;
2173 
2174 	while (buflen > 0) {
2175 		len = min_t(u32, buflen, PAGE_SIZE);
2176 		memcpy(dp, page_address(*pages), len);
2177 
2178 		buflen -= len;
2179 		dp += len;
2180 		pages++;
2181 	}
2182 
2183 	*bufp = tmp;
2184 	return 0;
2185 }
2186 
2187 /*
2188  * Get a user extended attribute name from the XDR buffer.
2189  * It will not have the "user." prefix, so prepend it.
2190  * Lastly, check for nul characters in the name.
2191  */
2192 static __be32
2193 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2194 {
2195 	char *name, *sp, *dp;
2196 	u32 namelen, cnt;
2197 	__be32 *p;
2198 
2199 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2200 		return nfserr_bad_xdr;
2201 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2202 		return nfserr_nametoolong;
2203 	if (namelen == 0)
2204 		return nfserr_bad_xdr;
2205 	p = xdr_inline_decode(argp->xdr, namelen);
2206 	if (!p)
2207 		return nfserr_bad_xdr;
2208 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2209 	if (!name)
2210 		return nfserr_jukebox;
2211 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2212 
2213 	/*
2214 	 * Copy the extended attribute name over while checking for 0
2215 	 * characters.
2216 	 */
2217 	sp = (char *)p;
2218 	dp = name + XATTR_USER_PREFIX_LEN;
2219 	cnt = namelen;
2220 
2221 	while (cnt-- > 0) {
2222 		if (*sp == '\0')
2223 			return nfserr_bad_xdr;
2224 		*dp++ = *sp++;
2225 	}
2226 	*dp = '\0';
2227 
2228 	*namep = name;
2229 
2230 	return nfs_ok;
2231 }
2232 
2233 /*
2234  * A GETXATTR op request comes without a length specifier. We just set the
2235  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2236  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2237  * check it against getxa_len, and allocate + return the value.
2238  */
2239 static __be32
2240 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2241 		      union nfsd4_op_u *u)
2242 {
2243 	struct nfsd4_getxattr *getxattr = &u->getxattr;
2244 	__be32 status;
2245 	u32 maxcount;
2246 
2247 	memset(getxattr, 0, sizeof(*getxattr));
2248 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2249 	if (status)
2250 		return status;
2251 
2252 	maxcount = svc_max_payload(argp->rqstp);
2253 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2254 
2255 	getxattr->getxa_len = maxcount;
2256 	return nfs_ok;
2257 }
2258 
2259 static __be32
2260 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2261 		      union nfsd4_op_u *u)
2262 {
2263 	struct nfsd4_setxattr *setxattr = &u->setxattr;
2264 	u32 flags, maxcount, size;
2265 	__be32 status;
2266 
2267 	memset(setxattr, 0, sizeof(*setxattr));
2268 
2269 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2270 		return nfserr_bad_xdr;
2271 
2272 	if (flags > SETXATTR4_REPLACE)
2273 		return nfserr_inval;
2274 	setxattr->setxa_flags = flags;
2275 
2276 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2277 	if (status)
2278 		return status;
2279 
2280 	maxcount = svc_max_payload(argp->rqstp);
2281 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2282 
2283 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2284 		return nfserr_bad_xdr;
2285 	if (size > maxcount)
2286 		return nfserr_xattr2big;
2287 
2288 	setxattr->setxa_len = size;
2289 	if (size > 0) {
2290 		struct xdr_buf payload;
2291 
2292 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2293 			return nfserr_bad_xdr;
2294 		status = nfsd4_vbuf_from_vector(argp, &payload,
2295 						&setxattr->setxa_buf, size);
2296 	}
2297 
2298 	return nfs_ok;
2299 }
2300 
2301 static __be32
2302 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2303 			union nfsd4_op_u *u)
2304 {
2305 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
2306 	u32 maxcount;
2307 
2308 	memset(listxattrs, 0, sizeof(*listxattrs));
2309 
2310 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2311 		return nfserr_bad_xdr;
2312 
2313 	/*
2314 	 * If the cookie  is too large to have even one user.x attribute
2315 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2316 	 */
2317 	if (listxattrs->lsxa_cookie >=
2318 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2319 		return nfserr_badcookie;
2320 
2321 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2322 		return nfserr_bad_xdr;
2323 	if (maxcount < 8)
2324 		/* Always need at least 2 words (length and one character) */
2325 		return nfserr_inval;
2326 
2327 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2328 	listxattrs->lsxa_maxcount = maxcount;
2329 
2330 	return nfs_ok;
2331 }
2332 
2333 static __be32
2334 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2335 			 union nfsd4_op_u *u)
2336 {
2337 	struct nfsd4_removexattr *removexattr = &u->removexattr;
2338 	memset(removexattr, 0, sizeof(*removexattr));
2339 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2340 }
2341 
2342 static __be32
2343 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2344 {
2345 	return nfs_ok;
2346 }
2347 
2348 static __be32
2349 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2350 {
2351 	return nfserr_notsupp;
2352 }
2353 
2354 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u);
2355 
2356 static const nfsd4_dec nfsd4_dec_ops[] = {
2357 	[OP_ACCESS]		= nfsd4_decode_access,
2358 	[OP_CLOSE]		= nfsd4_decode_close,
2359 	[OP_COMMIT]		= nfsd4_decode_commit,
2360 	[OP_CREATE]		= nfsd4_decode_create,
2361 	[OP_DELEGPURGE]		= nfsd4_decode_notsupp,
2362 	[OP_DELEGRETURN]	= nfsd4_decode_delegreturn,
2363 	[OP_GETATTR]		= nfsd4_decode_getattr,
2364 	[OP_GETFH]		= nfsd4_decode_noop,
2365 	[OP_LINK]		= nfsd4_decode_link,
2366 	[OP_LOCK]		= nfsd4_decode_lock,
2367 	[OP_LOCKT]		= nfsd4_decode_lockt,
2368 	[OP_LOCKU]		= nfsd4_decode_locku,
2369 	[OP_LOOKUP]		= nfsd4_decode_lookup,
2370 	[OP_LOOKUPP]		= nfsd4_decode_noop,
2371 	[OP_NVERIFY]		= nfsd4_decode_verify,
2372 	[OP_OPEN]		= nfsd4_decode_open,
2373 	[OP_OPENATTR]		= nfsd4_decode_notsupp,
2374 	[OP_OPEN_CONFIRM]	= nfsd4_decode_open_confirm,
2375 	[OP_OPEN_DOWNGRADE]	= nfsd4_decode_open_downgrade,
2376 	[OP_PUTFH]		= nfsd4_decode_putfh,
2377 	[OP_PUTPUBFH]		= nfsd4_decode_putpubfh,
2378 	[OP_PUTROOTFH]		= nfsd4_decode_noop,
2379 	[OP_READ]		= nfsd4_decode_read,
2380 	[OP_READDIR]		= nfsd4_decode_readdir,
2381 	[OP_READLINK]		= nfsd4_decode_noop,
2382 	[OP_REMOVE]		= nfsd4_decode_remove,
2383 	[OP_RENAME]		= nfsd4_decode_rename,
2384 	[OP_RENEW]		= nfsd4_decode_renew,
2385 	[OP_RESTOREFH]		= nfsd4_decode_noop,
2386 	[OP_SAVEFH]		= nfsd4_decode_noop,
2387 	[OP_SECINFO]		= nfsd4_decode_secinfo,
2388 	[OP_SETATTR]		= nfsd4_decode_setattr,
2389 	[OP_SETCLIENTID]	= nfsd4_decode_setclientid,
2390 	[OP_SETCLIENTID_CONFIRM] = nfsd4_decode_setclientid_confirm,
2391 	[OP_VERIFY]		= nfsd4_decode_verify,
2392 	[OP_WRITE]		= nfsd4_decode_write,
2393 	[OP_RELEASE_LOCKOWNER]	= nfsd4_decode_release_lockowner,
2394 
2395 	/* new operations for NFSv4.1 */
2396 	[OP_BACKCHANNEL_CTL]	= nfsd4_decode_backchannel_ctl,
2397 	[OP_BIND_CONN_TO_SESSION] = nfsd4_decode_bind_conn_to_session,
2398 	[OP_EXCHANGE_ID]	= nfsd4_decode_exchange_id,
2399 	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
2400 	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
2401 	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
2402 	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_get_dir_delegation,
2403 #ifdef CONFIG_NFSD_PNFS
2404 	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
2405 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2406 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_layoutcommit,
2407 	[OP_LAYOUTGET]		= nfsd4_decode_layoutget,
2408 	[OP_LAYOUTRETURN]	= nfsd4_decode_layoutreturn,
2409 #else
2410 	[OP_GETDEVICEINFO]	= nfsd4_decode_notsupp,
2411 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2412 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_notsupp,
2413 	[OP_LAYOUTGET]		= nfsd4_decode_notsupp,
2414 	[OP_LAYOUTRETURN]	= nfsd4_decode_notsupp,
2415 #endif
2416 	[OP_SECINFO_NO_NAME]	= nfsd4_decode_secinfo_no_name,
2417 	[OP_SEQUENCE]		= nfsd4_decode_sequence,
2418 	[OP_SET_SSV]		= nfsd4_decode_notsupp,
2419 	[OP_TEST_STATEID]	= nfsd4_decode_test_stateid,
2420 	[OP_WANT_DELEGATION]	= nfsd4_decode_notsupp,
2421 	[OP_DESTROY_CLIENTID]	= nfsd4_decode_destroy_clientid,
2422 	[OP_RECLAIM_COMPLETE]	= nfsd4_decode_reclaim_complete,
2423 
2424 	/* new operations for NFSv4.2 */
2425 	[OP_ALLOCATE]		= nfsd4_decode_fallocate,
2426 	[OP_COPY]		= nfsd4_decode_copy,
2427 	[OP_COPY_NOTIFY]	= nfsd4_decode_copy_notify,
2428 	[OP_DEALLOCATE]		= nfsd4_decode_fallocate,
2429 	[OP_IO_ADVISE]		= nfsd4_decode_notsupp,
2430 	[OP_LAYOUTERROR]	= nfsd4_decode_notsupp,
2431 	[OP_LAYOUTSTATS]	= nfsd4_decode_notsupp,
2432 	[OP_OFFLOAD_CANCEL]	= nfsd4_decode_offload_status,
2433 	[OP_OFFLOAD_STATUS]	= nfsd4_decode_offload_status,
2434 	[OP_READ_PLUS]		= nfsd4_decode_read,
2435 	[OP_SEEK]		= nfsd4_decode_seek,
2436 	[OP_WRITE_SAME]		= nfsd4_decode_notsupp,
2437 	[OP_CLONE]		= nfsd4_decode_clone,
2438 	/* RFC 8276 extended atributes operations */
2439 	[OP_GETXATTR]		= nfsd4_decode_getxattr,
2440 	[OP_SETXATTR]		= nfsd4_decode_setxattr,
2441 	[OP_LISTXATTRS]		= nfsd4_decode_listxattrs,
2442 	[OP_REMOVEXATTR]	= nfsd4_decode_removexattr,
2443 };
2444 
2445 static inline bool
2446 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2447 {
2448 	if (op->opnum < FIRST_NFS4_OP)
2449 		return false;
2450 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2451 		return false;
2452 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2453 		return false;
2454 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2455 		return false;
2456 	return true;
2457 }
2458 
2459 static bool
2460 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2461 {
2462 	struct nfsd4_op *op;
2463 	bool cachethis = false;
2464 	int auth_slack= argp->rqstp->rq_auth_slack;
2465 	int max_reply = auth_slack + 8; /* opcnt, status */
2466 	int readcount = 0;
2467 	int readbytes = 0;
2468 	__be32 *p;
2469 	int i;
2470 
2471 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2472 		return false;
2473 	max_reply += XDR_UNIT;
2474 	argp->tag = NULL;
2475 	if (unlikely(argp->taglen)) {
2476 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2477 			return false;
2478 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2479 		if (!p)
2480 			return false;
2481 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2482 		if (!argp->tag)
2483 			return false;
2484 		max_reply += xdr_align_size(argp->taglen);
2485 	}
2486 
2487 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2488 		return false;
2489 	if (xdr_stream_decode_u32(argp->xdr, &argp->client_opcnt) < 0)
2490 		return false;
2491 	argp->opcnt = min_t(u32, argp->client_opcnt,
2492 			    NFSD_MAX_OPS_PER_COMPOUND);
2493 
2494 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2495 		argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops));
2496 		if (!argp->ops) {
2497 			argp->ops = argp->iops;
2498 			return false;
2499 		}
2500 	}
2501 
2502 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2503 		argp->opcnt = 0;
2504 
2505 	for (i = 0; i < argp->opcnt; i++) {
2506 		op = &argp->ops[i];
2507 		op->replay = NULL;
2508 		op->opdesc = NULL;
2509 
2510 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2511 			return false;
2512 		if (nfsd4_opnum_in_range(argp, op)) {
2513 			op->opdesc = OPDESC(op);
2514 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2515 			if (op->status != nfs_ok)
2516 				trace_nfsd_compound_decode_err(argp->rqstp,
2517 							       argp->opcnt, i,
2518 							       op->opnum,
2519 							       op->status);
2520 		} else {
2521 			op->opnum = OP_ILLEGAL;
2522 			op->status = nfserr_op_illegal;
2523 		}
2524 
2525 		/*
2526 		 * We'll try to cache the result in the DRC if any one
2527 		 * op in the compound wants to be cached:
2528 		 */
2529 		cachethis |= nfsd4_cache_this_op(op);
2530 
2531 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2532 			readcount++;
2533 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2534 		} else
2535 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2536 		/*
2537 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2538 		 * (Special case because it will just skip encoding this
2539 		 * if it runs out of xdr buffer space, and it is the only
2540 		 * operation that behaves this way.)
2541 		 */
2542 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2543 			max_reply += NFS4_OPAQUE_LIMIT;
2544 
2545 		if (op->status) {
2546 			argp->opcnt = i+1;
2547 			break;
2548 		}
2549 	}
2550 	/* Sessions make the DRC unnecessary: */
2551 	if (argp->minorversion)
2552 		cachethis = false;
2553 	svc_reserve(argp->rqstp, max_reply + readbytes);
2554 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2555 
2556 	argp->splice_ok = nfsd_read_splice_ok(argp->rqstp);
2557 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2558 		argp->splice_ok = false;
2559 
2560 	return true;
2561 }
2562 
2563 static __be32 nfsd4_encode_nfs_fh4(struct xdr_stream *xdr,
2564 				   struct knfsd_fh *fh_handle)
2565 {
2566 	return nfsd4_encode_opaque(xdr, fh_handle->fh_raw, fh_handle->fh_size);
2567 }
2568 
2569 /* This is a frequently-encoded type; open-coded for speed */
2570 static __be32 nfsd4_encode_nfstime4(struct xdr_stream *xdr,
2571 				    const struct timespec64 *tv)
2572 {
2573 	__be32 *p;
2574 
2575 	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
2576 	if (!p)
2577 		return nfserr_resource;
2578 	p = xdr_encode_hyper(p, tv->tv_sec);
2579 	*p = cpu_to_be32(tv->tv_nsec);
2580 	return nfs_ok;
2581 }
2582 
2583 static __be32 nfsd4_encode_specdata4(struct xdr_stream *xdr,
2584 				     unsigned int major, unsigned int minor)
2585 {
2586 	__be32 status;
2587 
2588 	status = nfsd4_encode_uint32_t(xdr, major);
2589 	if (status != nfs_ok)
2590 		return status;
2591 	return nfsd4_encode_uint32_t(xdr, minor);
2592 }
2593 
2594 static __be32
2595 nfsd4_encode_change_info4(struct xdr_stream *xdr, const struct nfsd4_change_info *c)
2596 {
2597 	__be32 status;
2598 
2599 	status = nfsd4_encode_bool(xdr, c->atomic);
2600 	if (status != nfs_ok)
2601 		return status;
2602 	status = nfsd4_encode_changeid4(xdr, c->before_change);
2603 	if (status != nfs_ok)
2604 		return status;
2605 	return nfsd4_encode_changeid4(xdr, c->after_change);
2606 }
2607 
2608 static __be32 nfsd4_encode_netaddr4(struct xdr_stream *xdr,
2609 				    const struct nfs42_netaddr *addr)
2610 {
2611 	__be32 status;
2612 
2613 	/* na_r_netid */
2614 	status = nfsd4_encode_opaque(xdr, addr->netid, addr->netid_len);
2615 	if (status != nfs_ok)
2616 		return status;
2617 	/* na_r_addr */
2618 	return nfsd4_encode_opaque(xdr, addr->addr, addr->addr_len);
2619 }
2620 
2621 /* Encode as an array of strings the string given with components
2622  * separated @sep, escaped with esc_enter and esc_exit.
2623  */
2624 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2625 					  char *components, char esc_enter,
2626 					  char esc_exit)
2627 {
2628 	__be32 *p;
2629 	__be32 pathlen;
2630 	int pathlen_offset;
2631 	int strlen, count=0;
2632 	char *str, *end, *next;
2633 
2634 	dprintk("nfsd4_encode_components(%s)\n", components);
2635 
2636 	pathlen_offset = xdr->buf->len;
2637 	p = xdr_reserve_space(xdr, 4);
2638 	if (!p)
2639 		return nfserr_resource;
2640 	p++; /* We will fill this in with @count later */
2641 
2642 	end = str = components;
2643 	while (*end) {
2644 		bool found_esc = false;
2645 
2646 		/* try to parse as esc_start, ..., esc_end, sep */
2647 		if (*str == esc_enter) {
2648 			for (; *end && (*end != esc_exit); end++)
2649 				/* find esc_exit or end of string */;
2650 			next = end + 1;
2651 			if (*end && (!*next || *next == sep)) {
2652 				str++;
2653 				found_esc = true;
2654 			}
2655 		}
2656 
2657 		if (!found_esc)
2658 			for (; *end && (*end != sep); end++)
2659 				/* find sep or end of string */;
2660 
2661 		strlen = end - str;
2662 		if (strlen) {
2663 			p = xdr_reserve_space(xdr, strlen + 4);
2664 			if (!p)
2665 				return nfserr_resource;
2666 			p = xdr_encode_opaque(p, str, strlen);
2667 			count++;
2668 		}
2669 		else
2670 			end++;
2671 		if (found_esc)
2672 			end = next;
2673 
2674 		str = end;
2675 	}
2676 	pathlen = htonl(count);
2677 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2678 	return 0;
2679 }
2680 
2681 /* Encode as an array of strings the string given with components
2682  * separated @sep.
2683  */
2684 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2685 				      char *components)
2686 {
2687 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2688 }
2689 
2690 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2691 					struct nfsd4_fs_location *location)
2692 {
2693 	__be32 status;
2694 
2695 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2696 						'[', ']');
2697 	if (status)
2698 		return status;
2699 	status = nfsd4_encode_components(xdr, '/', location->path);
2700 	if (status)
2701 		return status;
2702 	return nfs_ok;
2703 }
2704 
2705 static __be32 nfsd4_encode_pathname4(struct xdr_stream *xdr,
2706 				     const struct path *root,
2707 				     const struct path *path)
2708 {
2709 	struct path cur = *path;
2710 	__be32 *p;
2711 	struct dentry **components = NULL;
2712 	unsigned int ncomponents = 0;
2713 	__be32 err = nfserr_jukebox;
2714 
2715 	dprintk("nfsd4_encode_components(");
2716 
2717 	path_get(&cur);
2718 	/* First walk the path up to the nfsd root, and store the
2719 	 * dentries/path components in an array.
2720 	 */
2721 	for (;;) {
2722 		if (path_equal(&cur, root))
2723 			break;
2724 		if (cur.dentry == cur.mnt->mnt_root) {
2725 			if (follow_up(&cur))
2726 				continue;
2727 			goto out_free;
2728 		}
2729 		if ((ncomponents & 15) == 0) {
2730 			struct dentry **new;
2731 			new = krealloc(components,
2732 					sizeof(*new) * (ncomponents + 16),
2733 					GFP_KERNEL);
2734 			if (!new)
2735 				goto out_free;
2736 			components = new;
2737 		}
2738 		components[ncomponents++] = cur.dentry;
2739 		cur.dentry = dget_parent(cur.dentry);
2740 	}
2741 	err = nfserr_resource;
2742 	p = xdr_reserve_space(xdr, 4);
2743 	if (!p)
2744 		goto out_free;
2745 	*p++ = cpu_to_be32(ncomponents);
2746 
2747 	while (ncomponents) {
2748 		struct dentry *dentry = components[ncomponents - 1];
2749 		unsigned int len;
2750 
2751 		spin_lock(&dentry->d_lock);
2752 		len = dentry->d_name.len;
2753 		p = xdr_reserve_space(xdr, len + 4);
2754 		if (!p) {
2755 			spin_unlock(&dentry->d_lock);
2756 			goto out_free;
2757 		}
2758 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2759 		dprintk("/%pd", dentry);
2760 		spin_unlock(&dentry->d_lock);
2761 		dput(dentry);
2762 		ncomponents--;
2763 	}
2764 
2765 	err = 0;
2766 out_free:
2767 	dprintk(")\n");
2768 	while (ncomponents)
2769 		dput(components[--ncomponents]);
2770 	kfree(components);
2771 	path_put(&cur);
2772 	return err;
2773 }
2774 
2775 static __be32 nfsd4_encode_fs_locations4(struct xdr_stream *xdr,
2776 					 struct svc_rqst *rqstp,
2777 					 struct svc_export *exp)
2778 {
2779 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2780 	struct svc_export *exp_ps;
2781 	unsigned int i;
2782 	__be32 status;
2783 
2784 	/* fs_root */
2785 	exp_ps = rqst_find_fsidzero_export(rqstp);
2786 	if (IS_ERR(exp_ps))
2787 		return nfserrno(PTR_ERR(exp_ps));
2788 	status = nfsd4_encode_pathname4(xdr, &exp_ps->ex_path, &exp->ex_path);
2789 	exp_put(exp_ps);
2790 	if (status != nfs_ok)
2791 		return status;
2792 
2793 	/* locations<> */
2794 	if (xdr_stream_encode_u32(xdr, fslocs->locations_count) != XDR_UNIT)
2795 		return nfserr_resource;
2796 	for (i = 0; i < fslocs->locations_count; i++) {
2797 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2798 		if (status != nfs_ok)
2799 			return status;
2800 	}
2801 
2802 	return nfs_ok;
2803 }
2804 
2805 static __be32 nfsd4_encode_nfsace4(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2806 				   struct nfs4_ace *ace)
2807 {
2808 	__be32 status;
2809 
2810 	/* type */
2811 	status = nfsd4_encode_acetype4(xdr, ace->type);
2812 	if (status != nfs_ok)
2813 		return nfserr_resource;
2814 	/* flag */
2815 	status = nfsd4_encode_aceflag4(xdr, ace->flag);
2816 	if (status != nfs_ok)
2817 		return nfserr_resource;
2818 	/* access mask */
2819 	status = nfsd4_encode_acemask4(xdr, ace->access_mask & NFS4_ACE_MASK_ALL);
2820 	if (status != nfs_ok)
2821 		return nfserr_resource;
2822 	/* who */
2823 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2824 		return nfs4_acl_write_who(xdr, ace->whotype);
2825 	if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2826 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2827 	return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2828 }
2829 
2830 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2831 			      FATTR4_WORD0_RDATTR_ERROR)
2832 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2833 #define WORD2_ABSENT_FS_ATTRS 0
2834 
2835 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2836 static inline __be32
2837 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2838 			    void *context, int len)
2839 {
2840 	__be32 *p;
2841 
2842 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2843 	if (!p)
2844 		return nfserr_resource;
2845 
2846 	/*
2847 	 * For now we use a 0 here to indicate the null translation; in
2848 	 * the future we may place a call to translation code here.
2849 	 */
2850 	*p++ = cpu_to_be32(0); /* lfs */
2851 	*p++ = cpu_to_be32(0); /* pi */
2852 	p = xdr_encode_opaque(p, context, len);
2853 	return 0;
2854 }
2855 #else
2856 static inline __be32
2857 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2858 			    void *context, int len)
2859 { return 0; }
2860 #endif
2861 
2862 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2863 {
2864 	/* As per referral draft:  */
2865 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2866 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2867 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2868 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2869 			*rdattr_err = NFSERR_MOVED;
2870 		else
2871 			return nfserr_moved;
2872 	}
2873 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2874 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2875 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2876 	return 0;
2877 }
2878 
2879 
2880 static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
2881 {
2882 	struct path path = exp->ex_path;
2883 	struct kstat stat;
2884 	int err;
2885 
2886 	path_get(&path);
2887 	while (follow_up(&path)) {
2888 		if (path.dentry != path.mnt->mnt_root)
2889 			break;
2890 	}
2891 	err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
2892 	path_put(&path);
2893 	if (!err)
2894 		*pino = stat.ino;
2895 	return err;
2896 }
2897 
2898 static __be32
2899 nfsd4_encode_bitmap4(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2900 {
2901 	__be32 *p;
2902 
2903 	if (bmval2) {
2904 		p = xdr_reserve_space(xdr, XDR_UNIT * 4);
2905 		if (!p)
2906 			goto out_resource;
2907 		*p++ = cpu_to_be32(3);
2908 		*p++ = cpu_to_be32(bmval0);
2909 		*p++ = cpu_to_be32(bmval1);
2910 		*p++ = cpu_to_be32(bmval2);
2911 	} else if (bmval1) {
2912 		p = xdr_reserve_space(xdr, XDR_UNIT * 3);
2913 		if (!p)
2914 			goto out_resource;
2915 		*p++ = cpu_to_be32(2);
2916 		*p++ = cpu_to_be32(bmval0);
2917 		*p++ = cpu_to_be32(bmval1);
2918 	} else {
2919 		p = xdr_reserve_space(xdr, XDR_UNIT * 2);
2920 		if (!p)
2921 			goto out_resource;
2922 		*p++ = cpu_to_be32(1);
2923 		*p++ = cpu_to_be32(bmval0);
2924 	}
2925 
2926 	return nfs_ok;
2927 out_resource:
2928 	return nfserr_resource;
2929 }
2930 
2931 struct nfsd4_fattr_args {
2932 	struct svc_rqst		*rqstp;
2933 	struct svc_fh		*fhp;
2934 	struct svc_export	*exp;
2935 	struct dentry		*dentry;
2936 	struct kstat		stat;
2937 	struct kstatfs		statfs;
2938 	struct nfs4_acl		*acl;
2939 	u64			size;
2940 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2941 	void			*context;
2942 	int			contextlen;
2943 #endif
2944 	u32			rdattr_err;
2945 	bool			contextsupport;
2946 	bool			ignore_crossmnt;
2947 };
2948 
2949 typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr,
2950 				const struct nfsd4_fattr_args *args);
2951 
2952 static __be32 nfsd4_encode_fattr4__noop(struct xdr_stream *xdr,
2953 					const struct nfsd4_fattr_args *args)
2954 {
2955 	return nfs_ok;
2956 }
2957 
2958 static __be32 nfsd4_encode_fattr4__true(struct xdr_stream *xdr,
2959 					const struct nfsd4_fattr_args *args)
2960 {
2961 	return nfsd4_encode_bool(xdr, true);
2962 }
2963 
2964 static __be32 nfsd4_encode_fattr4__false(struct xdr_stream *xdr,
2965 					 const struct nfsd4_fattr_args *args)
2966 {
2967 	return nfsd4_encode_bool(xdr, false);
2968 }
2969 
2970 static __be32 nfsd4_encode_fattr4_supported_attrs(struct xdr_stream *xdr,
2971 						  const struct nfsd4_fattr_args *args)
2972 {
2973 	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
2974 	u32 minorversion = resp->cstate.minorversion;
2975 	u32 supp[3];
2976 
2977 	memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2978 	if (!IS_POSIXACL(d_inode(args->dentry)))
2979 		supp[0] &= ~FATTR4_WORD0_ACL;
2980 	if (!args->contextsupport)
2981 		supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2982 
2983 	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
2984 }
2985 
2986 static __be32 nfsd4_encode_fattr4_type(struct xdr_stream *xdr,
2987 				       const struct nfsd4_fattr_args *args)
2988 {
2989 	__be32 *p;
2990 
2991 	p = xdr_reserve_space(xdr, XDR_UNIT);
2992 	if (!p)
2993 		return nfserr_resource;
2994 
2995 	switch (args->stat.mode & S_IFMT) {
2996 	case S_IFIFO:
2997 		*p = cpu_to_be32(NF4FIFO);
2998 		break;
2999 	case S_IFCHR:
3000 		*p = cpu_to_be32(NF4CHR);
3001 		break;
3002 	case S_IFDIR:
3003 		*p = cpu_to_be32(NF4DIR);
3004 		break;
3005 	case S_IFBLK:
3006 		*p = cpu_to_be32(NF4BLK);
3007 		break;
3008 	case S_IFLNK:
3009 		*p = cpu_to_be32(NF4LNK);
3010 		break;
3011 	case S_IFREG:
3012 		*p = cpu_to_be32(NF4REG);
3013 		break;
3014 	case S_IFSOCK:
3015 		*p = cpu_to_be32(NF4SOCK);
3016 		break;
3017 	default:
3018 		return nfserr_serverfault;
3019 	}
3020 
3021 	return nfs_ok;
3022 }
3023 
3024 static __be32 nfsd4_encode_fattr4_fh_expire_type(struct xdr_stream *xdr,
3025 						 const struct nfsd4_fattr_args *args)
3026 {
3027 	u32 mask;
3028 
3029 	mask = NFS4_FH_PERSISTENT;
3030 	if (!(args->exp->ex_flags & NFSEXP_NOSUBTREECHECK))
3031 		mask |= NFS4_FH_VOL_RENAME;
3032 	return nfsd4_encode_uint32_t(xdr, mask);
3033 }
3034 
3035 static __be32 nfsd4_encode_fattr4_change(struct xdr_stream *xdr,
3036 					 const struct nfsd4_fattr_args *args)
3037 {
3038 	const struct svc_export *exp = args->exp;
3039 	u64 c;
3040 
3041 	if (unlikely(exp->ex_flags & NFSEXP_V4ROOT)) {
3042 		u32 flush_time = convert_to_wallclock(exp->cd->flush_time);
3043 
3044 		if (xdr_stream_encode_u32(xdr, flush_time) != XDR_UNIT)
3045 			return nfserr_resource;
3046 		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
3047 			return nfserr_resource;
3048 		return nfs_ok;
3049 	}
3050 
3051 	c = nfsd4_change_attribute(&args->stat, d_inode(args->dentry));
3052 	return nfsd4_encode_changeid4(xdr, c);
3053 }
3054 
3055 static __be32 nfsd4_encode_fattr4_size(struct xdr_stream *xdr,
3056 				       const struct nfsd4_fattr_args *args)
3057 {
3058 	return nfsd4_encode_uint64_t(xdr, args->size);
3059 }
3060 
3061 static __be32 nfsd4_encode_fattr4_fsid(struct xdr_stream *xdr,
3062 				       const struct nfsd4_fattr_args *args)
3063 {
3064 	__be32 *p;
3065 
3066 	p = xdr_reserve_space(xdr, XDR_UNIT * 2 + XDR_UNIT * 2);
3067 	if (!p)
3068 		return nfserr_resource;
3069 
3070 	if (unlikely(args->exp->ex_fslocs.migrated)) {
3071 		p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
3072 		xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
3073 		return nfs_ok;
3074 	}
3075 	switch (fsid_source(args->fhp)) {
3076 	case FSIDSOURCE_FSID:
3077 		p = xdr_encode_hyper(p, (u64)args->exp->ex_fsid);
3078 		xdr_encode_hyper(p, (u64)0);
3079 		break;
3080 	case FSIDSOURCE_DEV:
3081 		*p++ = xdr_zero;
3082 		*p++ = cpu_to_be32(MAJOR(args->stat.dev));
3083 		*p++ = xdr_zero;
3084 		*p   = cpu_to_be32(MINOR(args->stat.dev));
3085 		break;
3086 	case FSIDSOURCE_UUID:
3087 		xdr_encode_opaque_fixed(p, args->exp->ex_uuid, EX_UUID_LEN);
3088 		break;
3089 	}
3090 
3091 	return nfs_ok;
3092 }
3093 
3094 static __be32 nfsd4_encode_fattr4_lease_time(struct xdr_stream *xdr,
3095 					     const struct nfsd4_fattr_args *args)
3096 {
3097 	struct nfsd_net *nn = net_generic(SVC_NET(args->rqstp), nfsd_net_id);
3098 
3099 	return nfsd4_encode_nfs_lease4(xdr, nn->nfsd4_lease);
3100 }
3101 
3102 static __be32 nfsd4_encode_fattr4_rdattr_error(struct xdr_stream *xdr,
3103 					       const struct nfsd4_fattr_args *args)
3104 {
3105 	return nfsd4_encode_uint32_t(xdr, args->rdattr_err);
3106 }
3107 
3108 static __be32 nfsd4_encode_fattr4_aclsupport(struct xdr_stream *xdr,
3109 					     const struct nfsd4_fattr_args *args)
3110 {
3111 	u32 mask;
3112 
3113 	mask = 0;
3114 	if (IS_POSIXACL(d_inode(args->dentry)))
3115 		mask = ACL4_SUPPORT_ALLOW_ACL | ACL4_SUPPORT_DENY_ACL;
3116 	return nfsd4_encode_uint32_t(xdr, mask);
3117 }
3118 
3119 static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,
3120 				      const struct nfsd4_fattr_args *args)
3121 {
3122 	struct nfs4_acl *acl = args->acl;
3123 	struct nfs4_ace *ace;
3124 	__be32 status;
3125 
3126 	/* nfsace4<> */
3127 	if (!acl) {
3128 		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
3129 			return nfserr_resource;
3130 	} else {
3131 		if (xdr_stream_encode_u32(xdr, acl->naces) != XDR_UNIT)
3132 			return nfserr_resource;
3133 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3134 			status = nfsd4_encode_nfsace4(xdr, args->rqstp, ace);
3135 			if (status != nfs_ok)
3136 				return status;
3137 		}
3138 	}
3139 	return nfs_ok;
3140 }
3141 
3142 static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,
3143 					     const struct nfsd4_fattr_args *args)
3144 {
3145 	return nfsd4_encode_nfs_fh4(xdr, &args->fhp->fh_handle);
3146 }
3147 
3148 static __be32 nfsd4_encode_fattr4_fileid(struct xdr_stream *xdr,
3149 					 const struct nfsd4_fattr_args *args)
3150 {
3151 	return nfsd4_encode_uint64_t(xdr, args->stat.ino);
3152 }
3153 
3154 static __be32 nfsd4_encode_fattr4_files_avail(struct xdr_stream *xdr,
3155 					      const struct nfsd4_fattr_args *args)
3156 {
3157 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
3158 }
3159 
3160 static __be32 nfsd4_encode_fattr4_files_free(struct xdr_stream *xdr,
3161 					     const struct nfsd4_fattr_args *args)
3162 {
3163 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
3164 }
3165 
3166 static __be32 nfsd4_encode_fattr4_files_total(struct xdr_stream *xdr,
3167 					      const struct nfsd4_fattr_args *args)
3168 {
3169 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_files);
3170 }
3171 
3172 static __be32 nfsd4_encode_fattr4_fs_locations(struct xdr_stream *xdr,
3173 					       const struct nfsd4_fattr_args *args)
3174 {
3175 	return nfsd4_encode_fs_locations4(xdr, args->rqstp, args->exp);
3176 }
3177 
3178 static __be32 nfsd4_encode_fattr4_maxfilesize(struct xdr_stream *xdr,
3179 					      const struct nfsd4_fattr_args *args)
3180 {
3181 	struct super_block *sb = args->exp->ex_path.mnt->mnt_sb;
3182 
3183 	return nfsd4_encode_uint64_t(xdr, sb->s_maxbytes);
3184 }
3185 
3186 static __be32 nfsd4_encode_fattr4_maxlink(struct xdr_stream *xdr,
3187 					  const struct nfsd4_fattr_args *args)
3188 {
3189 	return nfsd4_encode_uint32_t(xdr, 255);
3190 }
3191 
3192 static __be32 nfsd4_encode_fattr4_maxname(struct xdr_stream *xdr,
3193 					  const struct nfsd4_fattr_args *args)
3194 {
3195 	return nfsd4_encode_uint32_t(xdr, args->statfs.f_namelen);
3196 }
3197 
3198 static __be32 nfsd4_encode_fattr4_maxread(struct xdr_stream *xdr,
3199 					  const struct nfsd4_fattr_args *args)
3200 {
3201 	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
3202 }
3203 
3204 static __be32 nfsd4_encode_fattr4_maxwrite(struct xdr_stream *xdr,
3205 					   const struct nfsd4_fattr_args *args)
3206 {
3207 	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
3208 }
3209 
3210 static __be32 nfsd4_encode_fattr4_mode(struct xdr_stream *xdr,
3211 				       const struct nfsd4_fattr_args *args)
3212 {
3213 	return nfsd4_encode_mode4(xdr, args->stat.mode & S_IALLUGO);
3214 }
3215 
3216 static __be32 nfsd4_encode_fattr4_numlinks(struct xdr_stream *xdr,
3217 					   const struct nfsd4_fattr_args *args)
3218 {
3219 	return nfsd4_encode_uint32_t(xdr, args->stat.nlink);
3220 }
3221 
3222 static __be32 nfsd4_encode_fattr4_owner(struct xdr_stream *xdr,
3223 					const struct nfsd4_fattr_args *args)
3224 {
3225 	return nfsd4_encode_user(xdr, args->rqstp, args->stat.uid);
3226 }
3227 
3228 static __be32 nfsd4_encode_fattr4_owner_group(struct xdr_stream *xdr,
3229 					      const struct nfsd4_fattr_args *args)
3230 {
3231 	return nfsd4_encode_group(xdr, args->rqstp, args->stat.gid);
3232 }
3233 
3234 static __be32 nfsd4_encode_fattr4_rawdev(struct xdr_stream *xdr,
3235 					 const struct nfsd4_fattr_args *args)
3236 {
3237 	return nfsd4_encode_specdata4(xdr, MAJOR(args->stat.rdev),
3238 				      MINOR(args->stat.rdev));
3239 }
3240 
3241 static __be32 nfsd4_encode_fattr4_space_avail(struct xdr_stream *xdr,
3242 					      const struct nfsd4_fattr_args *args)
3243 {
3244 	u64 avail = (u64)args->statfs.f_bavail * (u64)args->statfs.f_bsize;
3245 
3246 	return nfsd4_encode_uint64_t(xdr, avail);
3247 }
3248 
3249 static __be32 nfsd4_encode_fattr4_space_free(struct xdr_stream *xdr,
3250 					     const struct nfsd4_fattr_args *args)
3251 {
3252 	u64 free = (u64)args->statfs.f_bfree * (u64)args->statfs.f_bsize;
3253 
3254 	return nfsd4_encode_uint64_t(xdr, free);
3255 }
3256 
3257 static __be32 nfsd4_encode_fattr4_space_total(struct xdr_stream *xdr,
3258 					      const struct nfsd4_fattr_args *args)
3259 {
3260 	u64 total = (u64)args->statfs.f_blocks * (u64)args->statfs.f_bsize;
3261 
3262 	return nfsd4_encode_uint64_t(xdr, total);
3263 }
3264 
3265 static __be32 nfsd4_encode_fattr4_space_used(struct xdr_stream *xdr,
3266 					     const struct nfsd4_fattr_args *args)
3267 {
3268 	return nfsd4_encode_uint64_t(xdr, (u64)args->stat.blocks << 9);
3269 }
3270 
3271 static __be32 nfsd4_encode_fattr4_time_access(struct xdr_stream *xdr,
3272 					      const struct nfsd4_fattr_args *args)
3273 {
3274 	return nfsd4_encode_nfstime4(xdr, &args->stat.atime);
3275 }
3276 
3277 static __be32 nfsd4_encode_fattr4_time_create(struct xdr_stream *xdr,
3278 					      const struct nfsd4_fattr_args *args)
3279 {
3280 	return nfsd4_encode_nfstime4(xdr, &args->stat.btime);
3281 }
3282 
3283 /*
3284  * ctime (in NFSv4, time_metadata) is not writeable, and the client
3285  * doesn't really care what resolution could theoretically be stored by
3286  * the filesystem.
3287  *
3288  * The client cares how close together changes can be while still
3289  * guaranteeing ctime changes.  For most filesystems (which have
3290  * timestamps with nanosecond fields) that is limited by the resolution
3291  * of the time returned from current_time() (which I'm assuming to be
3292  * 1/HZ).
3293  */
3294 static __be32 nfsd4_encode_fattr4_time_delta(struct xdr_stream *xdr,
3295 					     const struct nfsd4_fattr_args *args)
3296 {
3297 	const struct inode *inode = d_inode(args->dentry);
3298 	u32 ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
3299 	struct timespec64 ts = ns_to_timespec64(ns);
3300 
3301 	return nfsd4_encode_nfstime4(xdr, &ts);
3302 }
3303 
3304 static __be32 nfsd4_encode_fattr4_time_metadata(struct xdr_stream *xdr,
3305 						const struct nfsd4_fattr_args *args)
3306 {
3307 	return nfsd4_encode_nfstime4(xdr, &args->stat.ctime);
3308 }
3309 
3310 static __be32 nfsd4_encode_fattr4_time_modify(struct xdr_stream *xdr,
3311 					      const struct nfsd4_fattr_args *args)
3312 {
3313 	return nfsd4_encode_nfstime4(xdr, &args->stat.mtime);
3314 }
3315 
3316 static __be32 nfsd4_encode_fattr4_mounted_on_fileid(struct xdr_stream *xdr,
3317 						    const struct nfsd4_fattr_args *args)
3318 {
3319 	u64 ino;
3320 	int err;
3321 
3322 	if (!args->ignore_crossmnt &&
3323 	    args->dentry == args->exp->ex_path.mnt->mnt_root) {
3324 		err = nfsd4_get_mounted_on_ino(args->exp, &ino);
3325 		if (err)
3326 			return nfserrno(err);
3327 	} else
3328 		ino = args->stat.ino;
3329 
3330 	return nfsd4_encode_uint64_t(xdr, ino);
3331 }
3332 
3333 #ifdef CONFIG_NFSD_PNFS
3334 
3335 static __be32 nfsd4_encode_fattr4_fs_layout_types(struct xdr_stream *xdr,
3336 						  const struct nfsd4_fattr_args *args)
3337 {
3338 	unsigned long mask = args->exp->ex_layout_types;
3339 	int i;
3340 
3341 	/* Hamming weight of @mask is the number of layout types to return */
3342 	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
3343 		return nfserr_resource;
3344 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
3345 		if (mask & BIT(i)) {
3346 			/* layouttype4 */
3347 			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
3348 				return nfserr_resource;
3349 		}
3350 	return nfs_ok;
3351 }
3352 
3353 static __be32 nfsd4_encode_fattr4_layout_types(struct xdr_stream *xdr,
3354 					       const struct nfsd4_fattr_args *args)
3355 {
3356 	unsigned long mask = args->exp->ex_layout_types;
3357 	int i;
3358 
3359 	/* Hamming weight of @mask is the number of layout types to return */
3360 	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
3361 		return nfserr_resource;
3362 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
3363 		if (mask & BIT(i)) {
3364 			/* layouttype4 */
3365 			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
3366 				return nfserr_resource;
3367 		}
3368 	return nfs_ok;
3369 }
3370 
3371 static __be32 nfsd4_encode_fattr4_layout_blksize(struct xdr_stream *xdr,
3372 						 const struct nfsd4_fattr_args *args)
3373 {
3374 	return nfsd4_encode_uint32_t(xdr, args->stat.blksize);
3375 }
3376 
3377 #endif
3378 
3379 static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr,
3380 						     const struct nfsd4_fattr_args *args)
3381 {
3382 	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
3383 	u32 supp[3];
3384 
3385 	memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp));
3386 	supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3387 	supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3388 	supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3389 
3390 	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
3391 }
3392 
3393 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3394 static __be32 nfsd4_encode_fattr4_sec_label(struct xdr_stream *xdr,
3395 					    const struct nfsd4_fattr_args *args)
3396 {
3397 	return nfsd4_encode_security_label(xdr, args->rqstp,
3398 					   args->context, args->contextlen);
3399 }
3400 #endif
3401 
3402 static __be32 nfsd4_encode_fattr4_xattr_support(struct xdr_stream *xdr,
3403 						const struct nfsd4_fattr_args *args)
3404 {
3405 	int err = xattr_supports_user_prefix(d_inode(args->dentry));
3406 
3407 	return nfsd4_encode_bool(xdr, err == 0);
3408 }
3409 
3410 static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {
3411 	[FATTR4_SUPPORTED_ATTRS]	= nfsd4_encode_fattr4_supported_attrs,
3412 	[FATTR4_TYPE]			= nfsd4_encode_fattr4_type,
3413 	[FATTR4_FH_EXPIRE_TYPE]		= nfsd4_encode_fattr4_fh_expire_type,
3414 	[FATTR4_CHANGE]			= nfsd4_encode_fattr4_change,
3415 	[FATTR4_SIZE]			= nfsd4_encode_fattr4_size,
3416 	[FATTR4_LINK_SUPPORT]		= nfsd4_encode_fattr4__true,
3417 	[FATTR4_SYMLINK_SUPPORT]	= nfsd4_encode_fattr4__true,
3418 	[FATTR4_NAMED_ATTR]		= nfsd4_encode_fattr4__false,
3419 	[FATTR4_FSID]			= nfsd4_encode_fattr4_fsid,
3420 	[FATTR4_UNIQUE_HANDLES]		= nfsd4_encode_fattr4__true,
3421 	[FATTR4_LEASE_TIME]		= nfsd4_encode_fattr4_lease_time,
3422 	[FATTR4_RDATTR_ERROR]		= nfsd4_encode_fattr4_rdattr_error,
3423 	[FATTR4_ACL]			= nfsd4_encode_fattr4_acl,
3424 	[FATTR4_ACLSUPPORT]		= nfsd4_encode_fattr4_aclsupport,
3425 	[FATTR4_ARCHIVE]		= nfsd4_encode_fattr4__noop,
3426 	[FATTR4_CANSETTIME]		= nfsd4_encode_fattr4__true,
3427 	[FATTR4_CASE_INSENSITIVE]	= nfsd4_encode_fattr4__false,
3428 	[FATTR4_CASE_PRESERVING]	= nfsd4_encode_fattr4__true,
3429 	[FATTR4_CHOWN_RESTRICTED]	= nfsd4_encode_fattr4__true,
3430 	[FATTR4_FILEHANDLE]		= nfsd4_encode_fattr4_filehandle,
3431 	[FATTR4_FILEID]			= nfsd4_encode_fattr4_fileid,
3432 	[FATTR4_FILES_AVAIL]		= nfsd4_encode_fattr4_files_avail,
3433 	[FATTR4_FILES_FREE]		= nfsd4_encode_fattr4_files_free,
3434 	[FATTR4_FILES_TOTAL]		= nfsd4_encode_fattr4_files_total,
3435 	[FATTR4_FS_LOCATIONS]		= nfsd4_encode_fattr4_fs_locations,
3436 	[FATTR4_HIDDEN]			= nfsd4_encode_fattr4__noop,
3437 	[FATTR4_HOMOGENEOUS]		= nfsd4_encode_fattr4__true,
3438 	[FATTR4_MAXFILESIZE]		= nfsd4_encode_fattr4_maxfilesize,
3439 	[FATTR4_MAXLINK]		= nfsd4_encode_fattr4_maxlink,
3440 	[FATTR4_MAXNAME]		= nfsd4_encode_fattr4_maxname,
3441 	[FATTR4_MAXREAD]		= nfsd4_encode_fattr4_maxread,
3442 	[FATTR4_MAXWRITE]		= nfsd4_encode_fattr4_maxwrite,
3443 	[FATTR4_MIMETYPE]		= nfsd4_encode_fattr4__noop,
3444 	[FATTR4_MODE]			= nfsd4_encode_fattr4_mode,
3445 	[FATTR4_NO_TRUNC]		= nfsd4_encode_fattr4__true,
3446 	[FATTR4_NUMLINKS]		= nfsd4_encode_fattr4_numlinks,
3447 	[FATTR4_OWNER]			= nfsd4_encode_fattr4_owner,
3448 	[FATTR4_OWNER_GROUP]		= nfsd4_encode_fattr4_owner_group,
3449 	[FATTR4_QUOTA_AVAIL_HARD]	= nfsd4_encode_fattr4__noop,
3450 	[FATTR4_QUOTA_AVAIL_SOFT]	= nfsd4_encode_fattr4__noop,
3451 	[FATTR4_QUOTA_USED]		= nfsd4_encode_fattr4__noop,
3452 	[FATTR4_RAWDEV]			= nfsd4_encode_fattr4_rawdev,
3453 	[FATTR4_SPACE_AVAIL]		= nfsd4_encode_fattr4_space_avail,
3454 	[FATTR4_SPACE_FREE]		= nfsd4_encode_fattr4_space_free,
3455 	[FATTR4_SPACE_TOTAL]		= nfsd4_encode_fattr4_space_total,
3456 	[FATTR4_SPACE_USED]		= nfsd4_encode_fattr4_space_used,
3457 	[FATTR4_SYSTEM]			= nfsd4_encode_fattr4__noop,
3458 	[FATTR4_TIME_ACCESS]		= nfsd4_encode_fattr4_time_access,
3459 	[FATTR4_TIME_ACCESS_SET]	= nfsd4_encode_fattr4__noop,
3460 	[FATTR4_TIME_BACKUP]		= nfsd4_encode_fattr4__noop,
3461 	[FATTR4_TIME_CREATE]		= nfsd4_encode_fattr4_time_create,
3462 	[FATTR4_TIME_DELTA]		= nfsd4_encode_fattr4_time_delta,
3463 	[FATTR4_TIME_METADATA]		= nfsd4_encode_fattr4_time_metadata,
3464 	[FATTR4_TIME_MODIFY]		= nfsd4_encode_fattr4_time_modify,
3465 	[FATTR4_TIME_MODIFY_SET]	= nfsd4_encode_fattr4__noop,
3466 	[FATTR4_MOUNTED_ON_FILEID]	= nfsd4_encode_fattr4_mounted_on_fileid,
3467 	[FATTR4_DIR_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
3468 	[FATTR4_DIRENT_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
3469 	[FATTR4_DACL]			= nfsd4_encode_fattr4__noop,
3470 	[FATTR4_SACL]			= nfsd4_encode_fattr4__noop,
3471 	[FATTR4_CHANGE_POLICY]		= nfsd4_encode_fattr4__noop,
3472 	[FATTR4_FS_STATUS]		= nfsd4_encode_fattr4__noop,
3473 
3474 #ifdef CONFIG_NFSD_PNFS
3475 	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4_fs_layout_types,
3476 	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
3477 	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4_layout_types,
3478 	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4_layout_blksize,
3479 	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
3480 #else
3481 	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4__noop,
3482 	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
3483 	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4__noop,
3484 	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4__noop,
3485 	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
3486 #endif
3487 
3488 	[FATTR4_FS_LOCATIONS_INFO]	= nfsd4_encode_fattr4__noop,
3489 	[FATTR4_MDSTHRESHOLD]		= nfsd4_encode_fattr4__noop,
3490 	[FATTR4_RETENTION_GET]		= nfsd4_encode_fattr4__noop,
3491 	[FATTR4_RETENTION_SET]		= nfsd4_encode_fattr4__noop,
3492 	[FATTR4_RETENTEVT_GET]		= nfsd4_encode_fattr4__noop,
3493 	[FATTR4_RETENTEVT_SET]		= nfsd4_encode_fattr4__noop,
3494 	[FATTR4_RETENTION_HOLD]		= nfsd4_encode_fattr4__noop,
3495 	[FATTR4_MODE_SET_MASKED]	= nfsd4_encode_fattr4__noop,
3496 	[FATTR4_SUPPATTR_EXCLCREAT]	= nfsd4_encode_fattr4_suppattr_exclcreat,
3497 	[FATTR4_FS_CHARSET_CAP]		= nfsd4_encode_fattr4__noop,
3498 	[FATTR4_CLONE_BLKSIZE]		= nfsd4_encode_fattr4__noop,
3499 	[FATTR4_SPACE_FREED]		= nfsd4_encode_fattr4__noop,
3500 	[FATTR4_CHANGE_ATTR_TYPE]	= nfsd4_encode_fattr4__noop,
3501 
3502 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3503 	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4_sec_label,
3504 #else
3505 	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4__noop,
3506 #endif
3507 
3508 	[FATTR4_MODE_UMASK]		= nfsd4_encode_fattr4__noop,
3509 	[FATTR4_XATTR_SUPPORT]		= nfsd4_encode_fattr4_xattr_support,
3510 };
3511 
3512 /*
3513  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
3514  * ourselves.
3515  */
3516 static __be32
3517 nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
3518 		    struct svc_fh *fhp, struct svc_export *exp,
3519 		    struct dentry *dentry, const u32 *bmval,
3520 		    int ignore_crossmnt)
3521 {
3522 	DECLARE_BITMAP(attr_bitmap, ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops));
3523 	struct nfsd4_fattr_args args;
3524 	struct svc_fh *tempfh = NULL;
3525 	int starting_len = xdr->buf->len;
3526 	__be32 *attrlen_p, status;
3527 	int attrlen_offset;
3528 	u32 attrmask[3];
3529 	int err;
3530 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
3531 	u32 minorversion = resp->cstate.minorversion;
3532 	struct path path = {
3533 		.mnt	= exp->ex_path.mnt,
3534 		.dentry	= dentry,
3535 	};
3536 	unsigned long bit;
3537 	bool file_modified = false;
3538 	u64 size = 0;
3539 
3540 	WARN_ON_ONCE(bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1);
3541 	WARN_ON_ONCE(!nfsd_attrs_supported(minorversion, bmval));
3542 
3543 	args.rqstp = rqstp;
3544 	args.exp = exp;
3545 	args.dentry = dentry;
3546 	args.ignore_crossmnt = (ignore_crossmnt != 0);
3547 	args.acl = NULL;
3548 
3549 	/*
3550 	 * Make a local copy of the attribute bitmap that can be modified.
3551 	 */
3552 	attrmask[0] = bmval[0];
3553 	attrmask[1] = bmval[1];
3554 	attrmask[2] = bmval[2];
3555 
3556 	args.rdattr_err = 0;
3557 	if (exp->ex_fslocs.migrated) {
3558 		status = fattr_handle_absent_fs(&attrmask[0], &attrmask[1],
3559 						&attrmask[2], &args.rdattr_err);
3560 		if (status)
3561 			goto out;
3562 	}
3563 	args.size = 0;
3564 	if (attrmask[0] & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {
3565 		status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry),
3566 					&file_modified, &size);
3567 		if (status)
3568 			goto out;
3569 	}
3570 
3571 	err = vfs_getattr(&path, &args.stat,
3572 			  STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
3573 			  AT_STATX_SYNC_AS_STAT);
3574 	if (err)
3575 		goto out_nfserr;
3576 	if (file_modified)
3577 		args.size = size;
3578 	else
3579 		args.size = args.stat.size;
3580 
3581 	if (!(args.stat.result_mask & STATX_BTIME))
3582 		/* underlying FS does not offer btime so we can't share it */
3583 		attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
3584 	if ((attrmask[0] & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
3585 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
3586 	    (attrmask[1] & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
3587 		       FATTR4_WORD1_SPACE_TOTAL))) {
3588 		err = vfs_statfs(&path, &args.statfs);
3589 		if (err)
3590 			goto out_nfserr;
3591 	}
3592 	if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) &&
3593 	    !fhp) {
3594 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
3595 		status = nfserr_jukebox;
3596 		if (!tempfh)
3597 			goto out;
3598 		fh_init(tempfh, NFS4_FHSIZE);
3599 		status = fh_compose(tempfh, exp, dentry, NULL);
3600 		if (status)
3601 			goto out;
3602 		args.fhp = tempfh;
3603 	} else
3604 		args.fhp = fhp;
3605 
3606 	if (attrmask[0] & FATTR4_WORD0_ACL) {
3607 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);
3608 		if (err == -EOPNOTSUPP)
3609 			attrmask[0] &= ~FATTR4_WORD0_ACL;
3610 		else if (err == -EINVAL) {
3611 			status = nfserr_attrnotsupp;
3612 			goto out;
3613 		} else if (err != 0)
3614 			goto out_nfserr;
3615 	}
3616 
3617 	args.contextsupport = false;
3618 
3619 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3620 	args.context = NULL;
3621 	if ((attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) ||
3622 	     attrmask[0] & FATTR4_WORD0_SUPPORTED_ATTRS) {
3623 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
3624 			err = security_inode_getsecctx(d_inode(dentry),
3625 						&args.context, &args.contextlen);
3626 		else
3627 			err = -EOPNOTSUPP;
3628 		args.contextsupport = (err == 0);
3629 		if (attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) {
3630 			if (err == -EOPNOTSUPP)
3631 				attrmask[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
3632 			else if (err)
3633 				goto out_nfserr;
3634 		}
3635 	}
3636 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3637 
3638 	/* attrmask */
3639 	status = nfsd4_encode_bitmap4(xdr, attrmask[0], attrmask[1],
3640 				      attrmask[2]);
3641 	if (status)
3642 		goto out;
3643 
3644 	/* attr_vals */
3645 	attrlen_offset = xdr->buf->len;
3646 	attrlen_p = xdr_reserve_space(xdr, XDR_UNIT);
3647 	if (!attrlen_p)
3648 		goto out_resource;
3649 	bitmap_from_arr32(attr_bitmap, attrmask,
3650 			  ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops));
3651 	for_each_set_bit(bit, attr_bitmap,
3652 			 ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops)) {
3653 		status = nfsd4_enc_fattr4_encode_ops[bit](xdr, &args);
3654 		if (status != nfs_ok)
3655 			goto out;
3656 	}
3657 	*attrlen_p = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
3658 	status = nfs_ok;
3659 
3660 out:
3661 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3662 	if (args.context)
3663 		security_release_secctx(args.context, args.contextlen);
3664 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3665 	kfree(args.acl);
3666 	if (tempfh) {
3667 		fh_put(tempfh);
3668 		kfree(tempfh);
3669 	}
3670 	if (status)
3671 		xdr_truncate_encode(xdr, starting_len);
3672 	return status;
3673 out_nfserr:
3674 	status = nfserrno(err);
3675 	goto out;
3676 out_resource:
3677 	status = nfserr_resource;
3678 	goto out;
3679 }
3680 
3681 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3682 				struct xdr_buf *buf, __be32 *p, int bytes)
3683 {
3684 	xdr->scratch.iov_len = 0;
3685 	memset(buf, 0, sizeof(struct xdr_buf));
3686 	buf->head[0].iov_base = p;
3687 	buf->head[0].iov_len = 0;
3688 	buf->len = 0;
3689 	xdr->buf = buf;
3690 	xdr->iov = buf->head;
3691 	xdr->p = p;
3692 	xdr->end = (void *)p + bytes;
3693 	buf->buflen = bytes;
3694 }
3695 
3696 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3697 			struct svc_fh *fhp, struct svc_export *exp,
3698 			struct dentry *dentry, u32 *bmval,
3699 			struct svc_rqst *rqstp, int ignore_crossmnt)
3700 {
3701 	struct xdr_buf dummy;
3702 	struct xdr_stream xdr;
3703 	__be32 ret;
3704 
3705 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3706 	ret = nfsd4_encode_fattr4(rqstp, &xdr, fhp, exp, dentry, bmval,
3707 				  ignore_crossmnt);
3708 	*p = xdr.p;
3709 	return ret;
3710 }
3711 
3712 /*
3713  * The buffer space for this field was reserved during a previous
3714  * call to nfsd4_encode_entry4().
3715  */
3716 static void nfsd4_encode_entry4_nfs_cookie4(const struct nfsd4_readdir *readdir,
3717 					    u64 offset)
3718 {
3719 	__be64 cookie = cpu_to_be64(offset);
3720 	struct xdr_stream *xdr = readdir->xdr;
3721 
3722 	if (!readdir->cookie_offset)
3723 		return;
3724 	write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset, &cookie,
3725 			       sizeof(cookie));
3726 }
3727 
3728 static inline int attributes_need_mount(u32 *bmval)
3729 {
3730 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3731 		return 1;
3732 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3733 		return 1;
3734 	return 0;
3735 }
3736 
3737 static __be32
3738 nfsd4_encode_entry4_fattr(struct nfsd4_readdir *cd, const char *name,
3739 			  int namlen)
3740 {
3741 	struct svc_export *exp = cd->rd_fhp->fh_export;
3742 	struct dentry *dentry;
3743 	__be32 nfserr;
3744 	int ignore_crossmnt = 0;
3745 
3746 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3747 	if (IS_ERR(dentry))
3748 		return nfserrno(PTR_ERR(dentry));
3749 
3750 	exp_get(exp);
3751 	/*
3752 	 * In the case of a mountpoint, the client may be asking for
3753 	 * attributes that are only properties of the underlying filesystem
3754 	 * as opposed to the cross-mounted file system. In such a case,
3755 	 * we will not follow the cross mount and will fill the attribtutes
3756 	 * directly from the mountpoint dentry.
3757 	 */
3758 	if (nfsd_mountpoint(dentry, exp)) {
3759 		int err;
3760 
3761 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3762 				&& !attributes_need_mount(cd->rd_bmval)) {
3763 			ignore_crossmnt = 1;
3764 			goto out_encode;
3765 		}
3766 		/*
3767 		 * Why the heck aren't we just using nfsd_lookup??
3768 		 * Different "."/".." handling?  Something else?
3769 		 * At least, add a comment here to explain....
3770 		 */
3771 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3772 		if (err) {
3773 			nfserr = nfserrno(err);
3774 			goto out_put;
3775 		}
3776 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3777 		if (nfserr)
3778 			goto out_put;
3779 
3780 	}
3781 out_encode:
3782 	nfserr = nfsd4_encode_fattr4(cd->rd_rqstp, cd->xdr, NULL, exp, dentry,
3783 				     cd->rd_bmval, ignore_crossmnt);
3784 out_put:
3785 	dput(dentry);
3786 	exp_put(exp);
3787 	return nfserr;
3788 }
3789 
3790 static __be32
3791 nfsd4_encode_entry4_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3792 {
3793 	__be32 status;
3794 
3795 	/* attrmask */
3796 	status = nfsd4_encode_bitmap4(xdr, FATTR4_WORD0_RDATTR_ERROR, 0, 0);
3797 	if (status != nfs_ok)
3798 		return status;
3799 	/* attr_vals */
3800 	if (xdr_stream_encode_u32(xdr, XDR_UNIT) != XDR_UNIT)
3801 		return nfserr_resource;
3802 	/* rdattr_error */
3803 	if (xdr_stream_encode_be32(xdr, nfserr) != XDR_UNIT)
3804 		return nfserr_resource;
3805 	return nfs_ok;
3806 }
3807 
3808 static int
3809 nfsd4_encode_entry4(void *ccdv, const char *name, int namlen,
3810 		    loff_t offset, u64 ino, unsigned int d_type)
3811 {
3812 	struct readdir_cd *ccd = ccdv;
3813 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3814 	struct xdr_stream *xdr = cd->xdr;
3815 	int start_offset = xdr->buf->len;
3816 	int cookie_offset;
3817 	u32 name_and_cookie;
3818 	int entry_bytes;
3819 	__be32 nfserr = nfserr_toosmall;
3820 
3821 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3822 	if (name && isdotent(name, namlen)) {
3823 		cd->common.err = nfs_ok;
3824 		return 0;
3825 	}
3826 
3827 	/* Encode the previous entry's cookie value */
3828 	nfsd4_encode_entry4_nfs_cookie4(cd, offset);
3829 
3830 	if (xdr_stream_encode_item_present(xdr) != XDR_UNIT)
3831 		goto fail;
3832 
3833 	/* Reserve send buffer space for this entry's cookie value. */
3834 	cookie_offset = xdr->buf->len;
3835 	if (nfsd4_encode_nfs_cookie4(xdr, OFFSET_MAX) != nfs_ok)
3836 		goto fail;
3837 	if (nfsd4_encode_component4(xdr, name, namlen) != nfs_ok)
3838 		goto fail;
3839 	nfserr = nfsd4_encode_entry4_fattr(cd, name, namlen);
3840 	switch (nfserr) {
3841 	case nfs_ok:
3842 		break;
3843 	case nfserr_resource:
3844 		nfserr = nfserr_toosmall;
3845 		goto fail;
3846 	case nfserr_noent:
3847 		xdr_truncate_encode(xdr, start_offset);
3848 		goto skip_entry;
3849 	case nfserr_jukebox:
3850 		/*
3851 		 * The pseudoroot should only display dentries that lead to
3852 		 * exports. If we get EJUKEBOX here, then we can't tell whether
3853 		 * this entry should be included. Just fail the whole READDIR
3854 		 * with NFS4ERR_DELAY in that case, and hope that the situation
3855 		 * will resolve itself by the client's next attempt.
3856 		 */
3857 		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
3858 			goto fail;
3859 		fallthrough;
3860 	default:
3861 		/*
3862 		 * If the client requested the RDATTR_ERROR attribute,
3863 		 * we stuff the error code into this attribute
3864 		 * and continue.  If this attribute was not requested,
3865 		 * then in accordance with the spec, we fail the
3866 		 * entire READDIR operation(!)
3867 		 */
3868 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3869 			goto fail;
3870 		if (nfsd4_encode_entry4_rdattr_error(xdr, nfserr)) {
3871 			nfserr = nfserr_toosmall;
3872 			goto fail;
3873 		}
3874 	}
3875 	nfserr = nfserr_toosmall;
3876 	entry_bytes = xdr->buf->len - start_offset;
3877 	if (entry_bytes > cd->rd_maxcount)
3878 		goto fail;
3879 	cd->rd_maxcount -= entry_bytes;
3880 	/*
3881 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3882 	 * notes that it could be zero. If it is zero, then the server
3883 	 * should enforce only the rd_maxcount value.
3884 	 */
3885 	if (cd->rd_dircount) {
3886 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3887 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3888 			goto fail;
3889 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3890 		if (!cd->rd_dircount)
3891 			cd->rd_maxcount = 0;
3892 	}
3893 
3894 	cd->cookie_offset = cookie_offset;
3895 skip_entry:
3896 	cd->common.err = nfs_ok;
3897 	return 0;
3898 fail:
3899 	xdr_truncate_encode(xdr, start_offset);
3900 	cd->common.err = nfserr;
3901 	return -EINVAL;
3902 }
3903 
3904 static __be32
3905 nfsd4_encode_verifier4(struct xdr_stream *xdr, const nfs4_verifier *verf)
3906 {
3907 	__be32 *p;
3908 
3909 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3910 	if (!p)
3911 		return nfserr_resource;
3912 	memcpy(p, verf->data, sizeof(verf->data));
3913 	return nfs_ok;
3914 }
3915 
3916 static __be32
3917 nfsd4_encode_clientid4(struct xdr_stream *xdr, const clientid_t *clientid)
3918 {
3919 	__be32 *p;
3920 
3921 	p = xdr_reserve_space(xdr, sizeof(__be64));
3922 	if (!p)
3923 		return nfserr_resource;
3924 	memcpy(p, clientid, sizeof(*clientid));
3925 	return nfs_ok;
3926 }
3927 
3928 /* This is a frequently-encoded item; open-coded for speed */
3929 static __be32
3930 nfsd4_encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
3931 {
3932 	__be32 *p;
3933 
3934 	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
3935 	if (!p)
3936 		return nfserr_resource;
3937 	*p++ = cpu_to_be32(sid->si_generation);
3938 	memcpy(p, &sid->si_opaque, sizeof(sid->si_opaque));
3939 	return nfs_ok;
3940 }
3941 
3942 static __be32
3943 nfsd4_encode_sessionid4(struct xdr_stream *xdr,
3944 			const struct nfs4_sessionid *sessionid)
3945 {
3946 	return nfsd4_encode_opaque_fixed(xdr, sessionid->data,
3947 					 NFS4_MAX_SESSIONID_LEN);
3948 }
3949 
3950 static __be32
3951 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr,
3952 		    union nfsd4_op_u *u)
3953 {
3954 	struct nfsd4_access *access = &u->access;
3955 	struct xdr_stream *xdr = resp->xdr;
3956 	__be32 status;
3957 
3958 	/* supported */
3959 	status = nfsd4_encode_uint32_t(xdr, access->ac_supported);
3960 	if (status != nfs_ok)
3961 		return status;
3962 	/* access */
3963 	return nfsd4_encode_uint32_t(xdr, access->ac_resp_access);
3964 }
3965 
3966 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr,
3967 						union nfsd4_op_u *u)
3968 {
3969 	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
3970 	struct xdr_stream *xdr = resp->xdr;
3971 
3972 	/* bctsr_sessid */
3973 	nfserr = nfsd4_encode_sessionid4(xdr, &bcts->sessionid);
3974 	if (nfserr != nfs_ok)
3975 		return nfserr;
3976 	/* bctsr_dir */
3977 	if (xdr_stream_encode_u32(xdr, bcts->dir) != XDR_UNIT)
3978 		return nfserr_resource;
3979 	/* bctsr_use_conn_in_rdma_mode */
3980 	return nfsd4_encode_bool(xdr, false);
3981 }
3982 
3983 static __be32
3984 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr,
3985 		   union nfsd4_op_u *u)
3986 {
3987 	struct nfsd4_close *close = &u->close;
3988 	struct xdr_stream *xdr = resp->xdr;
3989 
3990 	/* open_stateid */
3991 	return nfsd4_encode_stateid4(xdr, &close->cl_stateid);
3992 }
3993 
3994 
3995 static __be32
3996 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr,
3997 		    union nfsd4_op_u *u)
3998 {
3999 	struct nfsd4_commit *commit = &u->commit;
4000 
4001 	return nfsd4_encode_verifier4(resp->xdr, &commit->co_verf);
4002 }
4003 
4004 static __be32
4005 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr,
4006 		    union nfsd4_op_u *u)
4007 {
4008 	struct nfsd4_create *create = &u->create;
4009 	struct xdr_stream *xdr = resp->xdr;
4010 
4011 	/* cinfo */
4012 	nfserr = nfsd4_encode_change_info4(xdr, &create->cr_cinfo);
4013 	if (nfserr)
4014 		return nfserr;
4015 	/* attrset */
4016 	return nfsd4_encode_bitmap4(xdr, create->cr_bmval[0],
4017 				    create->cr_bmval[1], create->cr_bmval[2]);
4018 }
4019 
4020 static __be32
4021 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4022 		     union nfsd4_op_u *u)
4023 {
4024 	struct nfsd4_getattr *getattr = &u->getattr;
4025 	struct svc_fh *fhp = getattr->ga_fhp;
4026 	struct xdr_stream *xdr = resp->xdr;
4027 
4028 	/* obj_attributes */
4029 	return nfsd4_encode_fattr4(resp->rqstp, xdr, fhp, fhp->fh_export,
4030 				   fhp->fh_dentry, getattr->ga_bmval, 0);
4031 }
4032 
4033 static __be32
4034 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr,
4035 		   union nfsd4_op_u *u)
4036 {
4037 	struct xdr_stream *xdr = resp->xdr;
4038 	struct svc_fh *fhp = u->getfh;
4039 
4040 	/* object */
4041 	return nfsd4_encode_nfs_fh4(xdr, &fhp->fh_handle);
4042 }
4043 
4044 static __be32
4045 nfsd4_encode_lock_owner4(struct xdr_stream *xdr, const clientid_t *clientid,
4046 			 const struct xdr_netobj *owner)
4047 {
4048 	__be32 status;
4049 
4050 	/* clientid */
4051 	status = nfsd4_encode_clientid4(xdr, clientid);
4052 	if (status != nfs_ok)
4053 		return status;
4054 	/* owner */
4055 	return nfsd4_encode_opaque(xdr, owner->data, owner->len);
4056 }
4057 
4058 static __be32
4059 nfsd4_encode_lock4denied(struct xdr_stream *xdr,
4060 			 const struct nfsd4_lock_denied *ld)
4061 {
4062 	__be32 status;
4063 
4064 	/* offset */
4065 	status = nfsd4_encode_offset4(xdr, ld->ld_start);
4066 	if (status != nfs_ok)
4067 		return status;
4068 	/* length */
4069 	status = nfsd4_encode_length4(xdr, ld->ld_length);
4070 	if (status != nfs_ok)
4071 		return status;
4072 	/* locktype */
4073 	if (xdr_stream_encode_u32(xdr, ld->ld_type) != XDR_UNIT)
4074 		return nfserr_resource;
4075 	/* owner */
4076 	return nfsd4_encode_lock_owner4(xdr, &ld->ld_clientid,
4077 					&ld->ld_owner);
4078 }
4079 
4080 static __be32
4081 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr,
4082 		  union nfsd4_op_u *u)
4083 {
4084 	struct nfsd4_lock *lock = &u->lock;
4085 	struct xdr_stream *xdr = resp->xdr;
4086 	__be32 status;
4087 
4088 	switch (nfserr) {
4089 	case nfs_ok:
4090 		/* resok4 */
4091 		status = nfsd4_encode_stateid4(xdr, &lock->lk_resp_stateid);
4092 		break;
4093 	case nfserr_denied:
4094 		/* denied */
4095 		status = nfsd4_encode_lock4denied(xdr, &lock->lk_denied);
4096 		break;
4097 	default:
4098 		return nfserr;
4099 	}
4100 	return status != nfs_ok ? status : nfserr;
4101 }
4102 
4103 static __be32
4104 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr,
4105 		   union nfsd4_op_u *u)
4106 {
4107 	struct nfsd4_lockt *lockt = &u->lockt;
4108 	struct xdr_stream *xdr = resp->xdr;
4109 	__be32 status;
4110 
4111 	if (nfserr == nfserr_denied) {
4112 		/* denied */
4113 		status = nfsd4_encode_lock4denied(xdr, &lockt->lt_denied);
4114 		if (status != nfs_ok)
4115 			return status;
4116 	}
4117 	return nfserr;
4118 }
4119 
4120 static __be32
4121 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr,
4122 		   union nfsd4_op_u *u)
4123 {
4124 	struct nfsd4_locku *locku = &u->locku;
4125 	struct xdr_stream *xdr = resp->xdr;
4126 
4127 	/* lock_stateid */
4128 	return nfsd4_encode_stateid4(xdr, &locku->lu_stateid);
4129 }
4130 
4131 
4132 static __be32
4133 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr,
4134 		  union nfsd4_op_u *u)
4135 {
4136 	struct nfsd4_link *link = &u->link;
4137 	struct xdr_stream *xdr = resp->xdr;
4138 
4139 	return nfsd4_encode_change_info4(xdr, &link->li_cinfo);
4140 }
4141 
4142 /*
4143  * This implementation does not yet support returning an ACE in an
4144  * OPEN that offers a delegation.
4145  */
4146 static __be32
4147 nfsd4_encode_open_nfsace4(struct xdr_stream *xdr)
4148 {
4149 	__be32 status;
4150 
4151 	/* type */
4152 	status = nfsd4_encode_acetype4(xdr, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
4153 	if (status != nfs_ok)
4154 		return nfserr_resource;
4155 	/* flag */
4156 	status = nfsd4_encode_aceflag4(xdr, 0);
4157 	if (status != nfs_ok)
4158 		return nfserr_resource;
4159 	/* access mask */
4160 	status = nfsd4_encode_acemask4(xdr, 0);
4161 	if (status != nfs_ok)
4162 		return nfserr_resource;
4163 	/* who - empty for now */
4164 	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
4165 		return nfserr_resource;
4166 	return nfs_ok;
4167 }
4168 
4169 static __be32
4170 nfsd4_encode_open_read_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
4171 {
4172 	__be32 status;
4173 
4174 	/* stateid */
4175 	status = nfsd4_encode_stateid4(xdr, &open->op_delegate_stateid);
4176 	if (status != nfs_ok)
4177 		return status;
4178 	/* recall */
4179 	status = nfsd4_encode_bool(xdr, open->op_recall);
4180 	if (status != nfs_ok)
4181 		return status;
4182 	/* permissions */
4183 	return nfsd4_encode_open_nfsace4(xdr);
4184 }
4185 
4186 static __be32
4187 nfsd4_encode_nfs_space_limit4(struct xdr_stream *xdr, u64 filesize)
4188 {
4189 	/* limitby */
4190 	if (xdr_stream_encode_u32(xdr, NFS4_LIMIT_SIZE) != XDR_UNIT)
4191 		return nfserr_resource;
4192 	/* filesize */
4193 	return nfsd4_encode_uint64_t(xdr, filesize);
4194 }
4195 
4196 static __be32
4197 nfsd4_encode_open_write_delegation4(struct xdr_stream *xdr,
4198 				    struct nfsd4_open *open)
4199 {
4200 	__be32 status;
4201 
4202 	/* stateid */
4203 	status = nfsd4_encode_stateid4(xdr, &open->op_delegate_stateid);
4204 	if (status != nfs_ok)
4205 		return status;
4206 	/* recall */
4207 	status = nfsd4_encode_bool(xdr, open->op_recall);
4208 	if (status != nfs_ok)
4209 		return status;
4210 	/* space_limit */
4211 	status = nfsd4_encode_nfs_space_limit4(xdr, 0);
4212 	if (status != nfs_ok)
4213 		return status;
4214 	return nfsd4_encode_open_nfsace4(xdr);
4215 }
4216 
4217 static __be32
4218 nfsd4_encode_open_none_delegation4(struct xdr_stream *xdr,
4219 				   struct nfsd4_open *open)
4220 {
4221 	__be32 status = nfs_ok;
4222 
4223 	/* ond_why */
4224 	if (xdr_stream_encode_u32(xdr, open->op_why_no_deleg) != XDR_UNIT)
4225 		return nfserr_resource;
4226 	switch (open->op_why_no_deleg) {
4227 	case WND4_CONTENTION:
4228 		/* ond_server_will_push_deleg */
4229 		status = nfsd4_encode_bool(xdr, false);
4230 		break;
4231 	case WND4_RESOURCE:
4232 		/* ond_server_will_signal_avail */
4233 		status = nfsd4_encode_bool(xdr, false);
4234 	}
4235 	return status;
4236 }
4237 
4238 static __be32
4239 nfsd4_encode_open_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
4240 {
4241 	__be32 status;
4242 
4243 	/* delegation_type */
4244 	if (xdr_stream_encode_u32(xdr, open->op_delegate_type) != XDR_UNIT)
4245 		return nfserr_resource;
4246 	switch (open->op_delegate_type) {
4247 	case NFS4_OPEN_DELEGATE_NONE:
4248 		status = nfs_ok;
4249 		break;
4250 	case NFS4_OPEN_DELEGATE_READ:
4251 		/* read */
4252 		status = nfsd4_encode_open_read_delegation4(xdr, open);
4253 		break;
4254 	case NFS4_OPEN_DELEGATE_WRITE:
4255 		/* write */
4256 		status = nfsd4_encode_open_write_delegation4(xdr, open);
4257 		break;
4258 	case NFS4_OPEN_DELEGATE_NONE_EXT:
4259 		/* od_whynone */
4260 		status = nfsd4_encode_open_none_delegation4(xdr, open);
4261 		break;
4262 	default:
4263 		status = nfserr_serverfault;
4264 	}
4265 
4266 	return status;
4267 }
4268 
4269 static __be32
4270 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
4271 		  union nfsd4_op_u *u)
4272 {
4273 	struct nfsd4_open *open = &u->open;
4274 	struct xdr_stream *xdr = resp->xdr;
4275 
4276 	/* stateid */
4277 	nfserr = nfsd4_encode_stateid4(xdr, &open->op_stateid);
4278 	if (nfserr != nfs_ok)
4279 		return nfserr;
4280 	/* cinfo */
4281 	nfserr = nfsd4_encode_change_info4(xdr, &open->op_cinfo);
4282 	if (nfserr != nfs_ok)
4283 		return nfserr;
4284 	/* rflags */
4285 	nfserr = nfsd4_encode_uint32_t(xdr, open->op_rflags);
4286 	if (nfserr != nfs_ok)
4287 		return nfserr;
4288 	/* attrset */
4289 	nfserr = nfsd4_encode_bitmap4(xdr, open->op_bmval[0],
4290 				      open->op_bmval[1], open->op_bmval[2]);
4291 	if (nfserr != nfs_ok)
4292 		return nfserr;
4293 	/* delegation */
4294 	return nfsd4_encode_open_delegation4(xdr, open);
4295 }
4296 
4297 static __be32
4298 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr,
4299 			  union nfsd4_op_u *u)
4300 {
4301 	struct nfsd4_open_confirm *oc = &u->open_confirm;
4302 	struct xdr_stream *xdr = resp->xdr;
4303 
4304 	/* open_stateid */
4305 	return nfsd4_encode_stateid4(xdr, &oc->oc_resp_stateid);
4306 }
4307 
4308 static __be32
4309 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr,
4310 			    union nfsd4_op_u *u)
4311 {
4312 	struct nfsd4_open_downgrade *od = &u->open_downgrade;
4313 	struct xdr_stream *xdr = resp->xdr;
4314 
4315 	/* open_stateid */
4316 	return nfsd4_encode_stateid4(xdr, &od->od_stateid);
4317 }
4318 
4319 /*
4320  * The operation of this function assumes that this is the only
4321  * READ operation in the COMPOUND. If there are multiple READs,
4322  * we use nfsd4_encode_readv().
4323  */
4324 static __be32 nfsd4_encode_splice_read(
4325 				struct nfsd4_compoundres *resp,
4326 				struct nfsd4_read *read,
4327 				struct file *file, unsigned long maxcount)
4328 {
4329 	struct xdr_stream *xdr = resp->xdr;
4330 	struct xdr_buf *buf = xdr->buf;
4331 	int status, space_left;
4332 	__be32 nfserr;
4333 
4334 	/*
4335 	 * Make sure there is room at the end of buf->head for
4336 	 * svcxdr_encode_opaque_pages() to create a tail buffer
4337 	 * to XDR-pad the payload.
4338 	 */
4339 	if (xdr->iov != xdr->buf->head || xdr->end - xdr->p < 1)
4340 		return nfserr_resource;
4341 
4342 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
4343 				  file, read->rd_offset, &maxcount,
4344 				  &read->rd_eof);
4345 	read->rd_length = maxcount;
4346 	if (nfserr)
4347 		goto out_err;
4348 	svcxdr_encode_opaque_pages(read->rd_rqstp, xdr, buf->pages,
4349 				   buf->page_base, maxcount);
4350 	status = svc_encode_result_payload(read->rd_rqstp,
4351 					   buf->head[0].iov_len, maxcount);
4352 	if (status) {
4353 		nfserr = nfserrno(status);
4354 		goto out_err;
4355 	}
4356 
4357 	/*
4358 	 * Prepare to encode subsequent operations.
4359 	 *
4360 	 * xdr_truncate_encode() is not safe to use after a successful
4361 	 * splice read has been done, so the following stream
4362 	 * manipulations are open-coded.
4363 	 */
4364 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
4365 				buf->buflen - buf->len);
4366 	buf->buflen = buf->len + space_left;
4367 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
4368 
4369 	return nfs_ok;
4370 
4371 out_err:
4372 	/*
4373 	 * nfsd_splice_actor may have already messed with the
4374 	 * page length; reset it so as not to confuse
4375 	 * xdr_truncate_encode in our caller.
4376 	 */
4377 	buf->page_len = 0;
4378 	return nfserr;
4379 }
4380 
4381 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
4382 				 struct nfsd4_read *read,
4383 				 struct file *file, unsigned long maxcount)
4384 {
4385 	struct xdr_stream *xdr = resp->xdr;
4386 	unsigned int base = xdr->buf->page_len & ~PAGE_MASK;
4387 	unsigned int starting_len = xdr->buf->len;
4388 	__be32 zero = xdr_zero;
4389 	__be32 nfserr;
4390 
4391 	if (xdr_reserve_space_vec(xdr, maxcount) < 0)
4392 		return nfserr_resource;
4393 
4394 	nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, file,
4395 				read->rd_offset, &maxcount, base,
4396 				&read->rd_eof);
4397 	read->rd_length = maxcount;
4398 	if (nfserr)
4399 		return nfserr;
4400 	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
4401 		return nfserr_io;
4402 	xdr_truncate_encode(xdr, starting_len + xdr_align_size(maxcount));
4403 
4404 	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
4405 			       xdr_pad_size(maxcount));
4406 	return nfs_ok;
4407 }
4408 
4409 static __be32
4410 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
4411 		  union nfsd4_op_u *u)
4412 {
4413 	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
4414 	struct nfsd4_read *read = &u->read;
4415 	struct xdr_stream *xdr = resp->xdr;
4416 	int starting_len = xdr->buf->len;
4417 	bool splice_ok = argp->splice_ok;
4418 	unsigned long maxcount;
4419 	struct file *file;
4420 	__be32 *p;
4421 
4422 	if (nfserr)
4423 		return nfserr;
4424 	file = read->rd_nf->nf_file;
4425 
4426 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
4427 	if (!p) {
4428 		WARN_ON_ONCE(splice_ok);
4429 		return nfserr_resource;
4430 	}
4431 	if (resp->xdr->buf->page_len && splice_ok) {
4432 		WARN_ON_ONCE(1);
4433 		return nfserr_serverfault;
4434 	}
4435 	xdr_commit_encode(xdr);
4436 
4437 	maxcount = min_t(unsigned long, read->rd_length,
4438 			 (xdr->buf->buflen - xdr->buf->len));
4439 
4440 	if (file->f_op->splice_read && splice_ok)
4441 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4442 	else
4443 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4444 	if (nfserr) {
4445 		xdr_truncate_encode(xdr, starting_len);
4446 		return nfserr;
4447 	}
4448 
4449 	p = xdr_encode_bool(p, read->rd_eof);
4450 	*p = cpu_to_be32(read->rd_length);
4451 	return nfs_ok;
4452 }
4453 
4454 static __be32
4455 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr,
4456 		      union nfsd4_op_u *u)
4457 {
4458 	struct nfsd4_readlink *readlink = &u->readlink;
4459 	__be32 *p, *maxcount_p, zero = xdr_zero;
4460 	struct xdr_stream *xdr = resp->xdr;
4461 	int length_offset = xdr->buf->len;
4462 	int maxcount, status;
4463 
4464 	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
4465 	if (!maxcount_p)
4466 		return nfserr_resource;
4467 	maxcount = PAGE_SIZE;
4468 
4469 	p = xdr_reserve_space(xdr, maxcount);
4470 	if (!p)
4471 		return nfserr_resource;
4472 	/*
4473 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4474 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4475 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4476 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4477 	 */
4478 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4479 						(char *)p, &maxcount);
4480 	if (nfserr == nfserr_isdir)
4481 		nfserr = nfserr_inval;
4482 	if (nfserr)
4483 		goto out_err;
4484 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4485 					   maxcount);
4486 	if (status) {
4487 		nfserr = nfserrno(status);
4488 		goto out_err;
4489 	}
4490 	*maxcount_p = cpu_to_be32(maxcount);
4491 	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
4492 	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
4493 			       xdr_pad_size(maxcount));
4494 	return nfs_ok;
4495 
4496 out_err:
4497 	xdr_truncate_encode(xdr, length_offset);
4498 	return nfserr;
4499 }
4500 
4501 static __be32 nfsd4_encode_dirlist4(struct xdr_stream *xdr,
4502 				    struct nfsd4_readdir *readdir,
4503 				    u32 max_payload)
4504 {
4505 	int bytes_left, maxcount, starting_len = xdr->buf->len;
4506 	loff_t offset;
4507 	__be32 status;
4508 
4509 	/*
4510 	 * Number of bytes left for directory entries allowing for the
4511 	 * final 8 bytes of the readdir and a following failed op.
4512 	 */
4513 	bytes_left = xdr->buf->buflen - xdr->buf->len -
4514 		COMPOUND_ERR_SLACK_SPACE - XDR_UNIT * 2;
4515 	if (bytes_left < 0)
4516 		return nfserr_resource;
4517 	maxcount = min_t(u32, readdir->rd_maxcount, max_payload);
4518 
4519 	/*
4520 	 * The RFC defines rd_maxcount as the size of the
4521 	 * READDIR4resok structure, which includes the verifier
4522 	 * and the 8 bytes encoded at the end of this function.
4523 	 */
4524 	if (maxcount < XDR_UNIT * 4)
4525 		return nfserr_toosmall;
4526 	maxcount = min_t(int, maxcount - XDR_UNIT * 4, bytes_left);
4527 
4528 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0 */
4529 	if (!readdir->rd_dircount)
4530 		readdir->rd_dircount = max_payload;
4531 
4532 	/* *entries */
4533 	readdir->xdr = xdr;
4534 	readdir->rd_maxcount = maxcount;
4535 	readdir->common.err = 0;
4536 	readdir->cookie_offset = 0;
4537 	offset = readdir->rd_cookie;
4538 	status = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp, &offset,
4539 			      &readdir->common, nfsd4_encode_entry4);
4540 	if (status)
4541 		return status;
4542 	if (readdir->common.err == nfserr_toosmall &&
4543 	    xdr->buf->len == starting_len) {
4544 		/* No entries were encoded. Which limit did we hit? */
4545 		if (maxcount - XDR_UNIT * 4 < bytes_left)
4546 			/* It was the fault of rd_maxcount */
4547 			return nfserr_toosmall;
4548 		/* We ran out of buffer space */
4549 		return nfserr_resource;
4550 	}
4551 	/* Encode the final entry's cookie value */
4552 	nfsd4_encode_entry4_nfs_cookie4(readdir, offset);
4553 	/* No entries follow */
4554 	if (xdr_stream_encode_item_absent(xdr) != XDR_UNIT)
4555 		return nfserr_resource;
4556 
4557 	/* eof */
4558 	return nfsd4_encode_bool(xdr, readdir->common.err == nfserr_eof);
4559 }
4560 
4561 static __be32
4562 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr,
4563 		     union nfsd4_op_u *u)
4564 {
4565 	struct nfsd4_readdir *readdir = &u->readdir;
4566 	struct xdr_stream *xdr = resp->xdr;
4567 	int starting_len = xdr->buf->len;
4568 
4569 	/* cookieverf */
4570 	nfserr = nfsd4_encode_verifier4(xdr, &readdir->rd_verf);
4571 	if (nfserr != nfs_ok)
4572 		return nfserr;
4573 
4574 	/* reply */
4575 	nfserr = nfsd4_encode_dirlist4(xdr, readdir, svc_max_payload(resp->rqstp));
4576 	if (nfserr != nfs_ok)
4577 		xdr_truncate_encode(xdr, starting_len);
4578 	return nfserr;
4579 }
4580 
4581 static __be32
4582 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr,
4583 		    union nfsd4_op_u *u)
4584 {
4585 	struct nfsd4_remove *remove = &u->remove;
4586 	struct xdr_stream *xdr = resp->xdr;
4587 
4588 	return nfsd4_encode_change_info4(xdr, &remove->rm_cinfo);
4589 }
4590 
4591 static __be32
4592 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr,
4593 		    union nfsd4_op_u *u)
4594 {
4595 	struct nfsd4_rename *rename = &u->rename;
4596 	struct xdr_stream *xdr = resp->xdr;
4597 
4598 	nfserr = nfsd4_encode_change_info4(xdr, &rename->rn_sinfo);
4599 	if (nfserr)
4600 		return nfserr;
4601 	return nfsd4_encode_change_info4(xdr, &rename->rn_tinfo);
4602 }
4603 
4604 static __be32
4605 nfsd4_encode_rpcsec_gss_info(struct xdr_stream *xdr,
4606 			     struct rpcsec_gss_info *info)
4607 {
4608 	__be32 status;
4609 
4610 	/* oid */
4611 	if (xdr_stream_encode_opaque(xdr, info->oid.data, info->oid.len) < 0)
4612 		return nfserr_resource;
4613 	/* qop */
4614 	status = nfsd4_encode_qop4(xdr, info->qop);
4615 	if (status != nfs_ok)
4616 		return status;
4617 	/* service */
4618 	if (xdr_stream_encode_u32(xdr, info->service) != XDR_UNIT)
4619 		return nfserr_resource;
4620 
4621 	return nfs_ok;
4622 }
4623 
4624 static __be32
4625 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4626 {
4627 	u32 i, nflavs, supported;
4628 	struct exp_flavor_info *flavs;
4629 	struct exp_flavor_info def_flavs[2];
4630 	static bool report = true;
4631 	__be32 *flavorsp;
4632 	__be32 status;
4633 
4634 	if (exp->ex_nflavors) {
4635 		flavs = exp->ex_flavors;
4636 		nflavs = exp->ex_nflavors;
4637 	} else { /* Handling of some defaults in absence of real secinfo: */
4638 		flavs = def_flavs;
4639 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4640 			nflavs = 2;
4641 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4642 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4643 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4644 			nflavs = 1;
4645 			flavs[0].pseudoflavor
4646 					= svcauth_gss_flavor(exp->ex_client);
4647 		} else {
4648 			nflavs = 1;
4649 			flavs[0].pseudoflavor
4650 					= exp->ex_client->flavour->flavour;
4651 		}
4652 	}
4653 
4654 	supported = 0;
4655 	flavorsp = xdr_reserve_space(xdr, XDR_UNIT);
4656 	if (!flavorsp)
4657 		return nfserr_resource;
4658 
4659 	for (i = 0; i < nflavs; i++) {
4660 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4661 		struct rpcsec_gss_info info;
4662 
4663 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4664 			supported++;
4665 
4666 			/* flavor */
4667 			status = nfsd4_encode_uint32_t(xdr, RPC_AUTH_GSS);
4668 			if (status != nfs_ok)
4669 				return status;
4670 			/* flavor_info */
4671 			status = nfsd4_encode_rpcsec_gss_info(xdr, &info);
4672 			if (status != nfs_ok)
4673 				return status;
4674 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4675 			supported++;
4676 
4677 			/* flavor */
4678 			status = nfsd4_encode_uint32_t(xdr, pf);
4679 			if (status != nfs_ok)
4680 				return status;
4681 		} else {
4682 			if (report)
4683 				pr_warn("NFS: SECINFO: security flavor %u "
4684 					"is not supported\n", pf);
4685 		}
4686 	}
4687 
4688 	if (nflavs != supported)
4689 		report = false;
4690 	*flavorsp = cpu_to_be32(supported);
4691 	return 0;
4692 }
4693 
4694 static __be32
4695 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4696 		     union nfsd4_op_u *u)
4697 {
4698 	struct nfsd4_secinfo *secinfo = &u->secinfo;
4699 	struct xdr_stream *xdr = resp->xdr;
4700 
4701 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4702 }
4703 
4704 static __be32
4705 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4706 		     union nfsd4_op_u *u)
4707 {
4708 	struct nfsd4_secinfo_no_name *secinfo = &u->secinfo_no_name;
4709 	struct xdr_stream *xdr = resp->xdr;
4710 
4711 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4712 }
4713 
4714 static __be32
4715 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4716 		     union nfsd4_op_u *u)
4717 {
4718 	struct nfsd4_setattr *setattr = &u->setattr;
4719 	__be32 status;
4720 
4721 	switch (nfserr) {
4722 	case nfs_ok:
4723 		/* attrsset */
4724 		status = nfsd4_encode_bitmap4(resp->xdr, setattr->sa_bmval[0],
4725 					      setattr->sa_bmval[1],
4726 					      setattr->sa_bmval[2]);
4727 		break;
4728 	default:
4729 		/* attrsset */
4730 		status = nfsd4_encode_bitmap4(resp->xdr, 0, 0, 0);
4731 	}
4732 	return status != nfs_ok ? status : nfserr;
4733 }
4734 
4735 static __be32
4736 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr,
4737 			 union nfsd4_op_u *u)
4738 {
4739 	struct nfsd4_setclientid *scd = &u->setclientid;
4740 	struct xdr_stream *xdr = resp->xdr;
4741 
4742 	if (!nfserr) {
4743 		nfserr = nfsd4_encode_clientid4(xdr, &scd->se_clientid);
4744 		if (nfserr != nfs_ok)
4745 			goto out;
4746 		nfserr = nfsd4_encode_verifier4(xdr, &scd->se_confirm);
4747 	} else if (nfserr == nfserr_clid_inuse) {
4748 		/* empty network id */
4749 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4750 			nfserr = nfserr_resource;
4751 			goto out;
4752 		}
4753 		/* empty universal address */
4754 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4755 			nfserr = nfserr_resource;
4756 			goto out;
4757 		}
4758 	}
4759 out:
4760 	return nfserr;
4761 }
4762 
4763 static __be32
4764 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr,
4765 		   union nfsd4_op_u *u)
4766 {
4767 	struct nfsd4_write *write = &u->write;
4768 	struct xdr_stream *xdr = resp->xdr;
4769 
4770 	/* count */
4771 	nfserr = nfsd4_encode_count4(xdr, write->wr_bytes_written);
4772 	if (nfserr)
4773 		return nfserr;
4774 	/* committed */
4775 	if (xdr_stream_encode_u32(xdr, write->wr_how_written) != XDR_UNIT)
4776 		return nfserr_resource;
4777 	/* writeverf */
4778 	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
4779 }
4780 
4781 static __be32
4782 nfsd4_encode_state_protect_ops4(struct xdr_stream *xdr,
4783 				struct nfsd4_exchange_id *exid)
4784 {
4785 	__be32 status;
4786 
4787 	/* spo_must_enforce */
4788 	status = nfsd4_encode_bitmap4(xdr, exid->spo_must_enforce[0],
4789 				      exid->spo_must_enforce[1],
4790 				      exid->spo_must_enforce[2]);
4791 	if (status != nfs_ok)
4792 		return status;
4793 	/* spo_must_allow */
4794 	return nfsd4_encode_bitmap4(xdr, exid->spo_must_allow[0],
4795 				    exid->spo_must_allow[1],
4796 				    exid->spo_must_allow[2]);
4797 }
4798 
4799 static __be32
4800 nfsd4_encode_state_protect4_r(struct xdr_stream *xdr, struct nfsd4_exchange_id *exid)
4801 {
4802 	__be32 status;
4803 
4804 	if (xdr_stream_encode_u32(xdr, exid->spa_how) != XDR_UNIT)
4805 		return nfserr_resource;
4806 	switch (exid->spa_how) {
4807 	case SP4_NONE:
4808 		status = nfs_ok;
4809 		break;
4810 	case SP4_MACH_CRED:
4811 		/* spr_mach_ops */
4812 		status = nfsd4_encode_state_protect_ops4(xdr, exid);
4813 		break;
4814 	default:
4815 		status = nfserr_serverfault;
4816 	}
4817 	return status;
4818 }
4819 
4820 static __be32
4821 nfsd4_encode_server_owner4(struct xdr_stream *xdr, struct svc_rqst *rqstp)
4822 {
4823 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
4824 	__be32 status;
4825 
4826 	/* so_minor_id */
4827 	status = nfsd4_encode_uint64_t(xdr, 0);
4828 	if (status != nfs_ok)
4829 		return status;
4830 	/* so_major_id */
4831 	return nfsd4_encode_opaque(xdr, nn->nfsd_name, strlen(nn->nfsd_name));
4832 }
4833 
4834 static __be32
4835 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4836 			 union nfsd4_op_u *u)
4837 {
4838 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4839 	struct nfsd4_exchange_id *exid = &u->exchange_id;
4840 	struct xdr_stream *xdr = resp->xdr;
4841 
4842 	/* eir_clientid */
4843 	nfserr = nfsd4_encode_clientid4(xdr, &exid->clientid);
4844 	if (nfserr != nfs_ok)
4845 		return nfserr;
4846 	/* eir_sequenceid */
4847 	nfserr = nfsd4_encode_sequenceid4(xdr, exid->seqid);
4848 	if (nfserr != nfs_ok)
4849 		return nfserr;
4850 	/* eir_flags */
4851 	nfserr = nfsd4_encode_uint32_t(xdr, exid->flags);
4852 	if (nfserr != nfs_ok)
4853 		return nfserr;
4854 	/* eir_state_protect */
4855 	nfserr = nfsd4_encode_state_protect4_r(xdr, exid);
4856 	if (nfserr != nfs_ok)
4857 		return nfserr;
4858 	/* eir_server_owner */
4859 	nfserr = nfsd4_encode_server_owner4(xdr, resp->rqstp);
4860 	if (nfserr != nfs_ok)
4861 		return nfserr;
4862 	/* eir_server_scope */
4863 	nfserr = nfsd4_encode_opaque(xdr, nn->nfsd_name,
4864 				     strlen(nn->nfsd_name));
4865 	if (nfserr != nfs_ok)
4866 		return nfserr;
4867 	/* eir_server_impl_id<1> */
4868 	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
4869 		return nfserr_resource;
4870 
4871 	return nfs_ok;
4872 }
4873 
4874 static __be32
4875 nfsd4_encode_channel_attrs4(struct xdr_stream *xdr,
4876 			    const struct nfsd4_channel_attrs *attrs)
4877 {
4878 	__be32 status;
4879 
4880 	/* ca_headerpadsize */
4881 	status = nfsd4_encode_count4(xdr, 0);
4882 	if (status != nfs_ok)
4883 		return status;
4884 	/* ca_maxrequestsize */
4885 	status = nfsd4_encode_count4(xdr, attrs->maxreq_sz);
4886 	if (status != nfs_ok)
4887 		return status;
4888 	/* ca_maxresponsesize */
4889 	status = nfsd4_encode_count4(xdr, attrs->maxresp_sz);
4890 	if (status != nfs_ok)
4891 		return status;
4892 	/* ca_maxresponsesize_cached */
4893 	status = nfsd4_encode_count4(xdr, attrs->maxresp_cached);
4894 	if (status != nfs_ok)
4895 		return status;
4896 	/* ca_maxoperations */
4897 	status = nfsd4_encode_count4(xdr, attrs->maxops);
4898 	if (status != nfs_ok)
4899 		return status;
4900 	/* ca_maxrequests */
4901 	status = nfsd4_encode_count4(xdr, attrs->maxreqs);
4902 	if (status != nfs_ok)
4903 		return status;
4904 	/* ca_rdma_ird<1> */
4905 	if (xdr_stream_encode_u32(xdr, attrs->nr_rdma_attrs) != XDR_UNIT)
4906 		return nfserr_resource;
4907 	if (attrs->nr_rdma_attrs)
4908 		return nfsd4_encode_uint32_t(xdr, attrs->rdma_attrs);
4909 	return nfs_ok;
4910 }
4911 
4912 static __be32
4913 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4914 			    union nfsd4_op_u *u)
4915 {
4916 	struct nfsd4_create_session *sess = &u->create_session;
4917 	struct xdr_stream *xdr = resp->xdr;
4918 
4919 	/* csr_sessionid */
4920 	nfserr = nfsd4_encode_sessionid4(xdr, &sess->sessionid);
4921 	if (nfserr != nfs_ok)
4922 		return nfserr;
4923 	/* csr_sequence */
4924 	nfserr = nfsd4_encode_sequenceid4(xdr, sess->seqid);
4925 	if (nfserr != nfs_ok)
4926 		return nfserr;
4927 	/* csr_flags */
4928 	nfserr = nfsd4_encode_uint32_t(xdr, sess->flags);
4929 	if (nfserr != nfs_ok)
4930 		return nfserr;
4931 	/* csr_fore_chan_attrs */
4932 	nfserr = nfsd4_encode_channel_attrs4(xdr, &sess->fore_channel);
4933 	if (nfserr != nfs_ok)
4934 		return nfserr;
4935 	/* csr_back_chan_attrs */
4936 	return nfsd4_encode_channel_attrs4(xdr, &sess->back_channel);
4937 }
4938 
4939 static __be32
4940 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4941 		      union nfsd4_op_u *u)
4942 {
4943 	struct nfsd4_sequence *seq = &u->sequence;
4944 	struct xdr_stream *xdr = resp->xdr;
4945 
4946 	/* sr_sessionid */
4947 	nfserr = nfsd4_encode_sessionid4(xdr, &seq->sessionid);
4948 	if (nfserr != nfs_ok)
4949 		return nfserr;
4950 	/* sr_sequenceid */
4951 	nfserr = nfsd4_encode_sequenceid4(xdr, seq->seqid);
4952 	if (nfserr != nfs_ok)
4953 		return nfserr;
4954 	/* sr_slotid */
4955 	nfserr = nfsd4_encode_slotid4(xdr, seq->slotid);
4956 	if (nfserr != nfs_ok)
4957 		return nfserr;
4958 	/* Note slotid's are numbered from zero: */
4959 	/* sr_highest_slotid */
4960 	nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots - 1);
4961 	if (nfserr != nfs_ok)
4962 		return nfserr;
4963 	/* sr_target_highest_slotid */
4964 	nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots - 1);
4965 	if (nfserr != nfs_ok)
4966 		return nfserr;
4967 	/* sr_status_flags */
4968 	nfserr = nfsd4_encode_uint32_t(xdr, seq->status_flags);
4969 	if (nfserr != nfs_ok)
4970 		return nfserr;
4971 
4972 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4973 	return nfs_ok;
4974 }
4975 
4976 static __be32
4977 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4978 			  union nfsd4_op_u *u)
4979 {
4980 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
4981 	struct nfsd4_test_stateid_id *stateid, *next;
4982 	struct xdr_stream *xdr = resp->xdr;
4983 
4984 	/* tsr_status_codes<> */
4985 	if (xdr_stream_encode_u32(xdr, test_stateid->ts_num_ids) != XDR_UNIT)
4986 		return nfserr_resource;
4987 	list_for_each_entry_safe(stateid, next,
4988 				 &test_stateid->ts_stateid_list, ts_id_list) {
4989 		if (xdr_stream_encode_be32(xdr, stateid->ts_id_status) != XDR_UNIT)
4990 			return nfserr_resource;
4991 	}
4992 	return nfs_ok;
4993 }
4994 
4995 static __be32
4996 nfsd4_encode_get_dir_delegation(struct nfsd4_compoundres *resp, __be32 nfserr,
4997 				union nfsd4_op_u *u)
4998 {
4999 	struct nfsd4_get_dir_delegation *gdd = &u->get_dir_delegation;
5000 	struct xdr_stream *xdr = resp->xdr;
5001 	__be32 status = nfserr_resource;
5002 
5003 	switch(gdd->gddrnf_status) {
5004 	case GDD4_OK:
5005 		if (xdr_stream_encode_u32(xdr, GDD4_OK) != XDR_UNIT)
5006 			break;
5007 		status = nfsd4_encode_verifier4(xdr, &gdd->gddr_cookieverf);
5008 		if (status)
5009 			break;
5010 		status = nfsd4_encode_stateid4(xdr, &gdd->gddr_stateid);
5011 		if (status)
5012 			break;
5013 		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_notification[0], 0, 0);
5014 		if (status)
5015 			break;
5016 		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_child_attributes[0],
5017 						   gdd->gddr_child_attributes[1],
5018 						   gdd->gddr_child_attributes[2]);
5019 		if (status)
5020 			break;
5021 		status = nfsd4_encode_bitmap4(xdr, gdd->gddr_dir_attributes[0],
5022 						   gdd->gddr_dir_attributes[1],
5023 						   gdd->gddr_dir_attributes[2]);
5024 		break;
5025 	default:
5026 		pr_warn("nfsd: bad gddrnf_status (%u)\n", gdd->gddrnf_status);
5027 		gdd->gddrnf_will_signal_deleg_avail = 0;
5028 		fallthrough;
5029 	case GDD4_UNAVAIL:
5030 		if (xdr_stream_encode_u32(xdr, GDD4_UNAVAIL) != XDR_UNIT)
5031 			break;
5032 		status = nfsd4_encode_bool(xdr, gdd->gddrnf_will_signal_deleg_avail);
5033 		break;
5034 	}
5035 	return status;
5036 }
5037 
5038 #ifdef CONFIG_NFSD_PNFS
5039 static __be32
5040 nfsd4_encode_device_addr4(struct xdr_stream *xdr,
5041 			  const struct nfsd4_getdeviceinfo *gdev)
5042 {
5043 	u32 needed_len, starting_len = xdr->buf->len;
5044 	const struct nfsd4_layout_ops *ops;
5045 	__be32 status;
5046 
5047 	/* da_layout_type */
5048 	if (xdr_stream_encode_u32(xdr, gdev->gd_layout_type) != XDR_UNIT)
5049 		return nfserr_resource;
5050 	/* da_addr_body */
5051 	ops = nfsd4_layout_ops[gdev->gd_layout_type];
5052 	status = ops->encode_getdeviceinfo(xdr, gdev);
5053 	if (status != nfs_ok) {
5054 		/*
5055 		 * Don't burden the layout drivers with enforcing
5056 		 * gd_maxcount. Just tell the client to come back
5057 		 * with a bigger buffer if it's not enough.
5058 		 */
5059 		if (xdr->buf->len + XDR_UNIT > gdev->gd_maxcount)
5060 			goto toosmall;
5061 		return status;
5062 	}
5063 
5064 	return nfs_ok;
5065 
5066 toosmall:
5067 	needed_len = xdr->buf->len + XDR_UNIT;	/* notifications */
5068 	xdr_truncate_encode(xdr, starting_len);
5069 
5070 	status = nfsd4_encode_count4(xdr, needed_len);
5071 	if (status != nfs_ok)
5072 		return status;
5073 	return nfserr_toosmall;
5074 }
5075 
5076 static __be32
5077 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
5078 		union nfsd4_op_u *u)
5079 {
5080 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
5081 	struct xdr_stream *xdr = resp->xdr;
5082 
5083 	/* gdir_device_addr */
5084 	nfserr = nfsd4_encode_device_addr4(xdr, gdev);
5085 	if (nfserr)
5086 		return nfserr;
5087 	/* gdir_notification */
5088 	return nfsd4_encode_bitmap4(xdr, gdev->gd_notify_types, 0, 0);
5089 }
5090 
5091 static __be32
5092 nfsd4_encode_layout4(struct xdr_stream *xdr, const struct nfsd4_layoutget *lgp)
5093 {
5094 	const struct nfsd4_layout_ops *ops = nfsd4_layout_ops[lgp->lg_layout_type];
5095 	__be32 status;
5096 
5097 	/* lo_offset */
5098 	status = nfsd4_encode_offset4(xdr, lgp->lg_seg.offset);
5099 	if (status != nfs_ok)
5100 		return status;
5101 	/* lo_length */
5102 	status = nfsd4_encode_length4(xdr, lgp->lg_seg.length);
5103 	if (status != nfs_ok)
5104 		return status;
5105 	/* lo_iomode */
5106 	if (xdr_stream_encode_u32(xdr, lgp->lg_seg.iomode) != XDR_UNIT)
5107 		return nfserr_resource;
5108 	/* lo_content */
5109 	if (xdr_stream_encode_u32(xdr, lgp->lg_layout_type) != XDR_UNIT)
5110 		return nfserr_resource;
5111 	return ops->encode_layoutget(xdr, lgp);
5112 }
5113 
5114 static __be32
5115 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
5116 		union nfsd4_op_u *u)
5117 {
5118 	struct nfsd4_layoutget *lgp = &u->layoutget;
5119 	struct xdr_stream *xdr = resp->xdr;
5120 
5121 	/* logr_return_on_close */
5122 	nfserr = nfsd4_encode_bool(xdr, true);
5123 	if (nfserr != nfs_ok)
5124 		return nfserr;
5125 	/* logr_stateid */
5126 	nfserr = nfsd4_encode_stateid4(xdr, &lgp->lg_sid);
5127 	if (nfserr != nfs_ok)
5128 		return nfserr;
5129 	/* logr_layout<> */
5130 	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
5131 		return nfserr_resource;
5132 	return nfsd4_encode_layout4(xdr, lgp);
5133 }
5134 
5135 static __be32
5136 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
5137 			  union nfsd4_op_u *u)
5138 {
5139 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
5140 	struct xdr_stream *xdr = resp->xdr;
5141 
5142 	/* ns_sizechanged */
5143 	nfserr = nfsd4_encode_bool(xdr, lcp->lc_size_chg);
5144 	if (nfserr != nfs_ok)
5145 		return nfserr;
5146 	if (lcp->lc_size_chg)
5147 		/* ns_size */
5148 		return nfsd4_encode_length4(xdr, lcp->lc_newsize);
5149 	return nfs_ok;
5150 }
5151 
5152 static __be32
5153 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
5154 		union nfsd4_op_u *u)
5155 {
5156 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
5157 	struct xdr_stream *xdr = resp->xdr;
5158 
5159 	/* lrs_present */
5160 	nfserr = nfsd4_encode_bool(xdr, lrp->lrs_present);
5161 	if (nfserr != nfs_ok)
5162 		return nfserr;
5163 	if (lrp->lrs_present)
5164 		/* lrs_stateid */
5165 		return nfsd4_encode_stateid4(xdr, &lrp->lr_sid);
5166 	return nfs_ok;
5167 }
5168 #endif /* CONFIG_NFSD_PNFS */
5169 
5170 static __be32
5171 nfsd4_encode_write_response4(struct xdr_stream *xdr,
5172 			     const struct nfsd4_copy *copy)
5173 {
5174 	const struct nfsd42_write_res *write = &copy->cp_res;
5175 	u32 count = nfsd4_copy_is_sync(copy) ? 0 : 1;
5176 	__be32 status;
5177 
5178 	/* wr_callback_id<1> */
5179 	if (xdr_stream_encode_u32(xdr, count) != XDR_UNIT)
5180 		return nfserr_resource;
5181 	if (count) {
5182 		status = nfsd4_encode_stateid4(xdr, &write->cb_stateid);
5183 		if (status != nfs_ok)
5184 			return status;
5185 	}
5186 
5187 	/* wr_count */
5188 	status = nfsd4_encode_length4(xdr, write->wr_bytes_written);
5189 	if (status != nfs_ok)
5190 		return status;
5191 	/* wr_committed */
5192 	if (xdr_stream_encode_u32(xdr, write->wr_stable_how) != XDR_UNIT)
5193 		return nfserr_resource;
5194 	/* wr_writeverf */
5195 	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
5196 }
5197 
5198 static __be32 nfsd4_encode_copy_requirements4(struct xdr_stream *xdr,
5199 					      const struct nfsd4_copy *copy)
5200 {
5201 	__be32 status;
5202 
5203 	/* cr_consecutive */
5204 	status = nfsd4_encode_bool(xdr, true);
5205 	if (status != nfs_ok)
5206 		return status;
5207 	/* cr_synchronous */
5208 	return nfsd4_encode_bool(xdr, nfsd4_copy_is_sync(copy));
5209 }
5210 
5211 static __be32
5212 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
5213 		  union nfsd4_op_u *u)
5214 {
5215 	struct nfsd4_copy *copy = &u->copy;
5216 
5217 	nfserr = nfsd4_encode_write_response4(resp->xdr, copy);
5218 	if (nfserr != nfs_ok)
5219 		return nfserr;
5220 	return nfsd4_encode_copy_requirements4(resp->xdr, copy);
5221 }
5222 
5223 static __be32
5224 nfsd4_encode_netloc4(struct xdr_stream *xdr, const struct nl4_server *ns)
5225 {
5226 	__be32 status;
5227 
5228 	if (xdr_stream_encode_u32(xdr, ns->nl4_type) != XDR_UNIT)
5229 		return nfserr_resource;
5230 	switch (ns->nl4_type) {
5231 	case NL4_NETADDR:
5232 		/* nl_addr */
5233 		status = nfsd4_encode_netaddr4(xdr, &ns->u.nl4_addr);
5234 		break;
5235 	default:
5236 		status = nfserr_serverfault;
5237 	}
5238 	return status;
5239 }
5240 
5241 static __be32
5242 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
5243 			 union nfsd4_op_u *u)
5244 {
5245 	struct nfsd4_copy_notify *cn = &u->copy_notify;
5246 	struct xdr_stream *xdr = resp->xdr;
5247 
5248 	/* cnr_lease_time */
5249 	nfserr = nfsd4_encode_nfstime4(xdr, &cn->cpn_lease_time);
5250 	if (nfserr)
5251 		return nfserr;
5252 	/* cnr_stateid */
5253 	nfserr = nfsd4_encode_stateid4(xdr, &cn->cpn_cnr_stateid);
5254 	if (nfserr)
5255 		return nfserr;
5256 	/* cnr_source_server<> */
5257 	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
5258 		return nfserr_resource;
5259 	return nfsd4_encode_netloc4(xdr, cn->cpn_src);
5260 }
5261 
5262 static __be32
5263 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
5264 			    union nfsd4_op_u *u)
5265 {
5266 	struct nfsd4_offload_status *os = &u->offload_status;
5267 	struct xdr_stream *xdr = resp->xdr;
5268 
5269 	/* osr_count */
5270 	nfserr = nfsd4_encode_length4(xdr, os->count);
5271 	if (nfserr != nfs_ok)
5272 		return nfserr;
5273 	/* osr_complete<1> */
5274 	if (os->completed) {
5275 		if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
5276 			return nfserr_resource;
5277 		if (xdr_stream_encode_be32(xdr, os->status) != XDR_UNIT)
5278 			return nfserr_resource;
5279 	} else if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
5280 		return nfserr_resource;
5281 	return nfs_ok;
5282 }
5283 
5284 static __be32
5285 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
5286 			    struct nfsd4_read *read)
5287 {
5288 	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
5289 	struct file *file = read->rd_nf->nf_file;
5290 	struct xdr_stream *xdr = resp->xdr;
5291 	bool splice_ok = argp->splice_ok;
5292 	unsigned long maxcount;
5293 	__be32 nfserr, *p;
5294 
5295 	/* Content type, offset, byte count */
5296 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
5297 	if (!p)
5298 		return nfserr_io;
5299 	if (resp->xdr->buf->page_len && splice_ok) {
5300 		WARN_ON_ONCE(splice_ok);
5301 		return nfserr_serverfault;
5302 	}
5303 
5304 	maxcount = min_t(unsigned long, read->rd_length,
5305 			 (xdr->buf->buflen - xdr->buf->len));
5306 
5307 	if (file->f_op->splice_read && splice_ok)
5308 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
5309 	else
5310 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
5311 	if (nfserr)
5312 		return nfserr;
5313 
5314 	*p++ = cpu_to_be32(NFS4_CONTENT_DATA);
5315 	p = xdr_encode_hyper(p, read->rd_offset);
5316 	*p = cpu_to_be32(read->rd_length);
5317 
5318 	return nfs_ok;
5319 }
5320 
5321 static __be32
5322 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
5323 		       union nfsd4_op_u *u)
5324 {
5325 	struct nfsd4_read *read = &u->read;
5326 	struct file *file = read->rd_nf->nf_file;
5327 	struct xdr_stream *xdr = resp->xdr;
5328 	int starting_len = xdr->buf->len;
5329 	u32 segments = 0;
5330 	__be32 *p;
5331 
5332 	if (nfserr)
5333 		return nfserr;
5334 
5335 	/* eof flag, segment count */
5336 	p = xdr_reserve_space(xdr, 4 + 4);
5337 	if (!p)
5338 		return nfserr_io;
5339 	xdr_commit_encode(xdr);
5340 
5341 	read->rd_eof = read->rd_offset >= i_size_read(file_inode(file));
5342 	if (read->rd_eof)
5343 		goto out;
5344 
5345 	nfserr = nfsd4_encode_read_plus_data(resp, read);
5346 	if (nfserr) {
5347 		xdr_truncate_encode(xdr, starting_len);
5348 		return nfserr;
5349 	}
5350 
5351 	segments++;
5352 
5353 out:
5354 	p = xdr_encode_bool(p, read->rd_eof);
5355 	*p = cpu_to_be32(segments);
5356 	return nfserr;
5357 }
5358 
5359 static __be32
5360 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
5361 		  union nfsd4_op_u *u)
5362 {
5363 	struct nfsd4_seek *seek = &u->seek;
5364 	struct xdr_stream *xdr = resp->xdr;
5365 
5366 	/* sr_eof */
5367 	nfserr = nfsd4_encode_bool(xdr, seek->seek_eof);
5368 	if (nfserr != nfs_ok)
5369 		return nfserr;
5370 	/* sr_offset */
5371 	return nfsd4_encode_offset4(xdr, seek->seek_pos);
5372 }
5373 
5374 static __be32
5375 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr,
5376 		  union nfsd4_op_u *p)
5377 {
5378 	return nfserr;
5379 }
5380 
5381 /*
5382  * Encode kmalloc-ed buffer in to XDR stream.
5383  */
5384 static __be32
5385 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
5386 {
5387 	u32 cplen;
5388 	__be32 *p;
5389 
5390 	cplen = min_t(unsigned long, buflen,
5391 		      ((void *)xdr->end - (void *)xdr->p));
5392 	p = xdr_reserve_space(xdr, cplen);
5393 	if (!p)
5394 		return nfserr_resource;
5395 
5396 	memcpy(p, buf, cplen);
5397 	buf += cplen;
5398 	buflen -= cplen;
5399 
5400 	while (buflen) {
5401 		cplen = min_t(u32, buflen, PAGE_SIZE);
5402 		p = xdr_reserve_space(xdr, cplen);
5403 		if (!p)
5404 			return nfserr_resource;
5405 
5406 		memcpy(p, buf, cplen);
5407 
5408 		if (cplen < PAGE_SIZE) {
5409 			/*
5410 			 * We're done, with a length that wasn't page
5411 			 * aligned, so possibly not word aligned. Pad
5412 			 * any trailing bytes with 0.
5413 			 */
5414 			xdr_encode_opaque_fixed(p, NULL, cplen);
5415 			break;
5416 		}
5417 
5418 		buflen -= PAGE_SIZE;
5419 		buf += PAGE_SIZE;
5420 	}
5421 
5422 	return 0;
5423 }
5424 
5425 static __be32
5426 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5427 		      union nfsd4_op_u *u)
5428 {
5429 	struct nfsd4_getxattr *getxattr = &u->getxattr;
5430 	struct xdr_stream *xdr = resp->xdr;
5431 	__be32 *p, err;
5432 
5433 	p = xdr_reserve_space(xdr, 4);
5434 	if (!p)
5435 		return nfserr_resource;
5436 
5437 	*p = cpu_to_be32(getxattr->getxa_len);
5438 
5439 	if (getxattr->getxa_len == 0)
5440 		return 0;
5441 
5442 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
5443 				    getxattr->getxa_len);
5444 
5445 	kvfree(getxattr->getxa_buf);
5446 
5447 	return err;
5448 }
5449 
5450 static __be32
5451 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5452 		      union nfsd4_op_u *u)
5453 {
5454 	struct nfsd4_setxattr *setxattr = &u->setxattr;
5455 	struct xdr_stream *xdr = resp->xdr;
5456 
5457 	return nfsd4_encode_change_info4(xdr, &setxattr->setxa_cinfo);
5458 }
5459 
5460 /*
5461  * See if there are cookie values that can be rejected outright.
5462  */
5463 static __be32
5464 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5465 				u32 *offsetp)
5466 {
5467 	u64 cookie = listxattrs->lsxa_cookie;
5468 
5469 	/*
5470 	 * If the cookie is larger than the maximum number we can fit
5471 	 * in the buffer we just got back from vfs_listxattr, it's invalid.
5472 	 */
5473 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5474 		return nfserr_badcookie;
5475 
5476 	*offsetp = (u32)cookie;
5477 	return 0;
5478 }
5479 
5480 static __be32
5481 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5482 			union nfsd4_op_u *u)
5483 {
5484 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
5485 	struct xdr_stream *xdr = resp->xdr;
5486 	u32 cookie_offset, count_offset, eof;
5487 	u32 left, xdrleft, slen, count;
5488 	u32 xdrlen, offset;
5489 	u64 cookie;
5490 	char *sp;
5491 	__be32 status, tmp;
5492 	__be64 wire_cookie;
5493 	__be32 *p;
5494 	u32 nuser;
5495 
5496 	eof = 1;
5497 
5498 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5499 	if (status)
5500 		goto out;
5501 
5502 	/*
5503 	 * Reserve space for the cookie and the name array count. Record
5504 	 * the offsets to save them later.
5505 	 */
5506 	cookie_offset = xdr->buf->len;
5507 	count_offset = cookie_offset + 8;
5508 	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
5509 	if (!p) {
5510 		status = nfserr_resource;
5511 		goto out;
5512 	}
5513 
5514 	count = 0;
5515 	left = listxattrs->lsxa_len;
5516 	sp = listxattrs->lsxa_buf;
5517 	nuser = 0;
5518 
5519 	/* Bytes left is maxcount - 8 (cookie) - 4 (array count) */
5520 	xdrleft = listxattrs->lsxa_maxcount - XDR_UNIT * 3;
5521 
5522 	while (left > 0 && xdrleft > 0) {
5523 		slen = strlen(sp);
5524 
5525 		/*
5526 		 * Check if this is a "user." attribute, skip it if not.
5527 		 */
5528 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5529 			goto contloop;
5530 
5531 		slen -= XATTR_USER_PREFIX_LEN;
5532 		xdrlen = 4 + ((slen + 3) & ~3);
5533 		/* Check if both entry and eof can fit in the XDR buffer */
5534 		if (xdrlen + XDR_UNIT > xdrleft) {
5535 			if (count == 0) {
5536 				/*
5537 				 * Can't even fit the first attribute name.
5538 				 */
5539 				status = nfserr_toosmall;
5540 				goto out;
5541 			}
5542 			eof = 0;
5543 			goto wreof;
5544 		}
5545 
5546 		left -= XATTR_USER_PREFIX_LEN;
5547 		sp += XATTR_USER_PREFIX_LEN;
5548 		if (nuser++ < offset)
5549 			goto contloop;
5550 
5551 
5552 		p = xdr_reserve_space(xdr, xdrlen);
5553 		if (!p) {
5554 			status = nfserr_resource;
5555 			goto out;
5556 		}
5557 
5558 		xdr_encode_opaque(p, sp, slen);
5559 
5560 		xdrleft -= xdrlen;
5561 		count++;
5562 contloop:
5563 		sp += slen + 1;
5564 		left -= slen + 1;
5565 	}
5566 
5567 	/*
5568 	 * If there were user attributes to copy, but we didn't copy
5569 	 * any, the offset was too large (e.g. the cookie was invalid).
5570 	 */
5571 	if (nuser > 0 && count == 0) {
5572 		status = nfserr_badcookie;
5573 		goto out;
5574 	}
5575 
5576 wreof:
5577 	p = xdr_reserve_space(xdr, 4);
5578 	if (!p) {
5579 		status = nfserr_resource;
5580 		goto out;
5581 	}
5582 	*p = cpu_to_be32(eof);
5583 
5584 	cookie = offset + count;
5585 
5586 	wire_cookie = cpu_to_be64(cookie);
5587 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &wire_cookie, 8);
5588 	tmp = cpu_to_be32(count);
5589 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5590 out:
5591 	if (listxattrs->lsxa_len)
5592 		kvfree(listxattrs->lsxa_buf);
5593 	return status;
5594 }
5595 
5596 static __be32
5597 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5598 			 union nfsd4_op_u *u)
5599 {
5600 	struct nfsd4_removexattr *removexattr = &u->removexattr;
5601 	struct xdr_stream *xdr = resp->xdr;
5602 
5603 	return nfsd4_encode_change_info4(xdr, &removexattr->rmxa_cinfo);
5604 }
5605 
5606 typedef __be32(*nfsd4_enc)(struct nfsd4_compoundres *, __be32, union nfsd4_op_u *u);
5607 
5608 /*
5609  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5610  * since we don't need to filter out obsolete ops as this is
5611  * done in the decoding phase.
5612  */
5613 static const nfsd4_enc nfsd4_enc_ops[] = {
5614 	[OP_ACCESS]		= nfsd4_encode_access,
5615 	[OP_CLOSE]		= nfsd4_encode_close,
5616 	[OP_COMMIT]		= nfsd4_encode_commit,
5617 	[OP_CREATE]		= nfsd4_encode_create,
5618 	[OP_DELEGPURGE]		= nfsd4_encode_noop,
5619 	[OP_DELEGRETURN]	= nfsd4_encode_noop,
5620 	[OP_GETATTR]		= nfsd4_encode_getattr,
5621 	[OP_GETFH]		= nfsd4_encode_getfh,
5622 	[OP_LINK]		= nfsd4_encode_link,
5623 	[OP_LOCK]		= nfsd4_encode_lock,
5624 	[OP_LOCKT]		= nfsd4_encode_lockt,
5625 	[OP_LOCKU]		= nfsd4_encode_locku,
5626 	[OP_LOOKUP]		= nfsd4_encode_noop,
5627 	[OP_LOOKUPP]		= nfsd4_encode_noop,
5628 	[OP_NVERIFY]		= nfsd4_encode_noop,
5629 	[OP_OPEN]		= nfsd4_encode_open,
5630 	[OP_OPENATTR]		= nfsd4_encode_noop,
5631 	[OP_OPEN_CONFIRM]	= nfsd4_encode_open_confirm,
5632 	[OP_OPEN_DOWNGRADE]	= nfsd4_encode_open_downgrade,
5633 	[OP_PUTFH]		= nfsd4_encode_noop,
5634 	[OP_PUTPUBFH]		= nfsd4_encode_noop,
5635 	[OP_PUTROOTFH]		= nfsd4_encode_noop,
5636 	[OP_READ]		= nfsd4_encode_read,
5637 	[OP_READDIR]		= nfsd4_encode_readdir,
5638 	[OP_READLINK]		= nfsd4_encode_readlink,
5639 	[OP_REMOVE]		= nfsd4_encode_remove,
5640 	[OP_RENAME]		= nfsd4_encode_rename,
5641 	[OP_RENEW]		= nfsd4_encode_noop,
5642 	[OP_RESTOREFH]		= nfsd4_encode_noop,
5643 	[OP_SAVEFH]		= nfsd4_encode_noop,
5644 	[OP_SECINFO]		= nfsd4_encode_secinfo,
5645 	[OP_SETATTR]		= nfsd4_encode_setattr,
5646 	[OP_SETCLIENTID]	= nfsd4_encode_setclientid,
5647 	[OP_SETCLIENTID_CONFIRM] = nfsd4_encode_noop,
5648 	[OP_VERIFY]		= nfsd4_encode_noop,
5649 	[OP_WRITE]		= nfsd4_encode_write,
5650 	[OP_RELEASE_LOCKOWNER]	= nfsd4_encode_noop,
5651 
5652 	/* NFSv4.1 operations */
5653 	[OP_BACKCHANNEL_CTL]	= nfsd4_encode_noop,
5654 	[OP_BIND_CONN_TO_SESSION] = nfsd4_encode_bind_conn_to_session,
5655 	[OP_EXCHANGE_ID]	= nfsd4_encode_exchange_id,
5656 	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
5657 	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
5658 	[OP_FREE_STATEID]	= nfsd4_encode_noop,
5659 	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_get_dir_delegation,
5660 #ifdef CONFIG_NFSD_PNFS
5661 	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
5662 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5663 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_layoutcommit,
5664 	[OP_LAYOUTGET]		= nfsd4_encode_layoutget,
5665 	[OP_LAYOUTRETURN]	= nfsd4_encode_layoutreturn,
5666 #else
5667 	[OP_GETDEVICEINFO]	= nfsd4_encode_noop,
5668 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5669 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_noop,
5670 	[OP_LAYOUTGET]		= nfsd4_encode_noop,
5671 	[OP_LAYOUTRETURN]	= nfsd4_encode_noop,
5672 #endif
5673 	[OP_SECINFO_NO_NAME]	= nfsd4_encode_secinfo_no_name,
5674 	[OP_SEQUENCE]		= nfsd4_encode_sequence,
5675 	[OP_SET_SSV]		= nfsd4_encode_noop,
5676 	[OP_TEST_STATEID]	= nfsd4_encode_test_stateid,
5677 	[OP_WANT_DELEGATION]	= nfsd4_encode_noop,
5678 	[OP_DESTROY_CLIENTID]	= nfsd4_encode_noop,
5679 	[OP_RECLAIM_COMPLETE]	= nfsd4_encode_noop,
5680 
5681 	/* NFSv4.2 operations */
5682 	[OP_ALLOCATE]		= nfsd4_encode_noop,
5683 	[OP_COPY]		= nfsd4_encode_copy,
5684 	[OP_COPY_NOTIFY]	= nfsd4_encode_copy_notify,
5685 	[OP_DEALLOCATE]		= nfsd4_encode_noop,
5686 	[OP_IO_ADVISE]		= nfsd4_encode_noop,
5687 	[OP_LAYOUTERROR]	= nfsd4_encode_noop,
5688 	[OP_LAYOUTSTATS]	= nfsd4_encode_noop,
5689 	[OP_OFFLOAD_CANCEL]	= nfsd4_encode_noop,
5690 	[OP_OFFLOAD_STATUS]	= nfsd4_encode_offload_status,
5691 	[OP_READ_PLUS]		= nfsd4_encode_read_plus,
5692 	[OP_SEEK]		= nfsd4_encode_seek,
5693 	[OP_WRITE_SAME]		= nfsd4_encode_noop,
5694 	[OP_CLONE]		= nfsd4_encode_noop,
5695 
5696 	/* RFC 8276 extended atributes operations */
5697 	[OP_GETXATTR]		= nfsd4_encode_getxattr,
5698 	[OP_SETXATTR]		= nfsd4_encode_setxattr,
5699 	[OP_LISTXATTRS]		= nfsd4_encode_listxattrs,
5700 	[OP_REMOVEXATTR]	= nfsd4_encode_removexattr,
5701 };
5702 
5703 /*
5704  * Calculate whether we still have space to encode repsize bytes.
5705  * There are two considerations:
5706  *     - For NFS versions >=4.1, the size of the reply must stay within
5707  *       session limits
5708  *     - For all NFS versions, we must stay within limited preallocated
5709  *       buffer space.
5710  *
5711  * This is called before the operation is processed, so can only provide
5712  * an upper estimate.  For some nonidempotent operations (such as
5713  * getattr), it's not necessarily a problem if that estimate is wrong,
5714  * as we can fail it after processing without significant side effects.
5715  */
5716 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5717 {
5718 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5719 	struct nfsd4_slot *slot = resp->cstate.slot;
5720 
5721 	if (buf->len + respsize <= buf->buflen)
5722 		return nfs_ok;
5723 	if (!nfsd4_has_session(&resp->cstate))
5724 		return nfserr_resource;
5725 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5726 		WARN_ON_ONCE(1);
5727 		return nfserr_rep_too_big_to_cache;
5728 	}
5729 	return nfserr_rep_too_big;
5730 }
5731 
5732 void
5733 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5734 {
5735 	struct xdr_stream *xdr = resp->xdr;
5736 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5737 	struct svc_rqst *rqstp = resp->rqstp;
5738 	const struct nfsd4_operation *opdesc = op->opdesc;
5739 	int post_err_offset;
5740 	nfsd4_enc encoder;
5741 	__be32 *p;
5742 
5743 	p = xdr_reserve_space(xdr, 8);
5744 	if (!p)
5745 		goto release;
5746 	*p++ = cpu_to_be32(op->opnum);
5747 	post_err_offset = xdr->buf->len;
5748 
5749 	if (op->opnum == OP_ILLEGAL)
5750 		goto status;
5751 	if (op->status && opdesc &&
5752 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5753 		goto status;
5754 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5755 	       !nfsd4_enc_ops[op->opnum]);
5756 	encoder = nfsd4_enc_ops[op->opnum];
5757 	op->status = encoder(resp, op->status, &op->u);
5758 	if (op->status)
5759 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5760 	xdr_commit_encode(xdr);
5761 
5762 	/* nfsd4_check_resp_size guarantees enough room for error status */
5763 	if (!op->status) {
5764 		int space_needed = 0;
5765 		if (!nfsd4_last_compound_op(rqstp))
5766 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5767 		op->status = nfsd4_check_resp_size(resp, space_needed);
5768 	}
5769 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5770 		struct nfsd4_slot *slot = resp->cstate.slot;
5771 
5772 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5773 			op->status = nfserr_rep_too_big_to_cache;
5774 		else
5775 			op->status = nfserr_rep_too_big;
5776 	}
5777 	if (op->status == nfserr_resource ||
5778 	    op->status == nfserr_rep_too_big ||
5779 	    op->status == nfserr_rep_too_big_to_cache) {
5780 		/*
5781 		 * The operation may have already been encoded or
5782 		 * partially encoded.  No op returns anything additional
5783 		 * in the case of one of these three errors, so we can
5784 		 * just truncate back to after the status.  But it's a
5785 		 * bug if we had to do this on a non-idempotent op:
5786 		 */
5787 		warn_on_nonidempotent_op(op);
5788 		xdr_truncate_encode(xdr, post_err_offset);
5789 	}
5790 	if (so) {
5791 		int len = xdr->buf->len - post_err_offset;
5792 
5793 		so->so_replay.rp_status = op->status;
5794 		so->so_replay.rp_buflen = len;
5795 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5796 						so->so_replay.rp_buf, len);
5797 	}
5798 status:
5799 	*p = op->status;
5800 release:
5801 	if (opdesc && opdesc->op_release)
5802 		opdesc->op_release(&op->u);
5803 
5804 	/*
5805 	 * Account for pages consumed while encoding this operation.
5806 	 * The xdr_stream primitives don't manage rq_next_page.
5807 	 */
5808 	rqstp->rq_next_page = xdr->page_ptr + 1;
5809 }
5810 
5811 /**
5812  * nfsd4_encode_replay - encode a result stored in the stateowner reply cache
5813  * @xdr: send buffer's XDR stream
5814  * @op: operation being replayed
5815  *
5816  * @op->replay->rp_buf contains the previously-sent already-encoded result.
5817  */
5818 void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5819 {
5820 	struct nfs4_replay *rp = op->replay;
5821 
5822 	trace_nfsd_stateowner_replay(op->opnum, rp);
5823 
5824 	if (xdr_stream_encode_u32(xdr, op->opnum) != XDR_UNIT)
5825 		return;
5826 	if (xdr_stream_encode_be32(xdr, rp->rp_status) != XDR_UNIT)
5827 		return;
5828 	xdr_stream_encode_opaque_fixed(xdr, rp->rp_buf, rp->rp_buflen);
5829 }
5830 
5831 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5832 {
5833 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5834 
5835 	if (args->ops != args->iops) {
5836 		vfree(args->ops);
5837 		args->ops = args->iops;
5838 	}
5839 	while (args->to_free) {
5840 		struct svcxdr_tmpbuf *tb = args->to_free;
5841 		args->to_free = tb->next;
5842 		kfree(tb);
5843 	}
5844 }
5845 
5846 bool
5847 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5848 {
5849 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5850 
5851 	/* svcxdr_tmp_alloc */
5852 	args->to_free = NULL;
5853 
5854 	args->xdr = xdr;
5855 	args->ops = args->iops;
5856 	args->rqstp = rqstp;
5857 
5858 	return nfsd4_decode_compound(args);
5859 }
5860 
5861 bool
5862 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5863 {
5864 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5865 	__be32 *p;
5866 
5867 	/*
5868 	 * Send buffer space for the following items is reserved
5869 	 * at the top of nfsd4_proc_compound().
5870 	 */
5871 	p = resp->statusp;
5872 
5873 	*p++ = resp->cstate.status;
5874 	*p++ = htonl(resp->taglen);
5875 	memcpy(p, resp->tag, resp->taglen);
5876 	p += XDR_QUADLEN(resp->taglen);
5877 	*p++ = htonl(resp->opcnt);
5878 
5879 	nfsd4_sequence_done(resp);
5880 	return true;
5881 }
5882