xref: /linux/fs/nfsd/nfs4xdr.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 /*
2  *  Server-side XDR for NFSv4
3  *
4  *  Copyright (c) 2002 The Regents of the University of Michigan.
5  *  All rights reserved.
6  *
7  *  Kendrick Smith <kmsmith@umich.edu>
8  *  Andy Adamson   <andros@umich.edu>
9  *
10  *  Redistribution and use in source and binary forms, with or without
11  *  modification, are permitted provided that the following conditions
12  *  are met:
13  *
14  *  1. Redistributions of source code must retain the above copyright
15  *     notice, this list of conditions and the following disclaimer.
16  *  2. Redistributions in binary form must reproduce the above copyright
17  *     notice, this list of conditions and the following disclaimer in the
18  *     documentation and/or other materials provided with the distribution.
19  *  3. Neither the name of the University nor the names of its
20  *     contributors may be used to endorse or promote products derived
21  *     from this software without specific prior written permission.
22  *
23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 #include <linux/file.h>
37 #include <linux/slab.h>
38 #include <linux/namei.h>
39 #include <linux/statfs.h>
40 #include <linux/utsname.h>
41 #include <linux/pagemap.h>
42 #include <linux/sunrpc/svcauth_gss.h>
43 #include <linux/sunrpc/addr.h>
44 #include <linux/xattr.h>
45 #include <linux/vmalloc.h>
46 
47 #include <uapi/linux/xattr.h>
48 
49 #include "idmap.h"
50 #include "acl.h"
51 #include "xdr4.h"
52 #include "vfs.h"
53 #include "state.h"
54 #include "cache.h"
55 #include "netns.h"
56 #include "pnfs.h"
57 #include "filecache.h"
58 
59 #include "trace.h"
60 
61 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
62 #include <linux/security.h>
63 #endif
64 
65 
66 #define NFSDDBG_FACILITY		NFSDDBG_XDR
67 
68 const u32 nfsd_suppattrs[3][3] = {
69 	{NFSD4_SUPPORTED_ATTRS_WORD0,
70 	 NFSD4_SUPPORTED_ATTRS_WORD1,
71 	 NFSD4_SUPPORTED_ATTRS_WORD2},
72 
73 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
74 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
75 	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
76 
77 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
78 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
79 	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
80 };
81 
82 /*
83  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
84  * directory in order to indicate to the client that a filesystem boundary is present
85  * We use a fixed fsid for a referral
86  */
87 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
88 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
89 
90 static __be32
91 check_filename(char *str, int len)
92 {
93 	int i;
94 
95 	if (len == 0)
96 		return nfserr_inval;
97 	if (len > NFS4_MAXNAMLEN)
98 		return nfserr_nametoolong;
99 	if (isdotent(str, len))
100 		return nfserr_badname;
101 	for (i = 0; i < len; i++)
102 		if (str[i] == '/')
103 			return nfserr_badname;
104 	return 0;
105 }
106 
107 static int zero_clientid(clientid_t *clid)
108 {
109 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
110 }
111 
112 /**
113  * svcxdr_tmpalloc - allocate memory to be freed after compound processing
114  * @argp: NFSv4 compound argument structure
115  * @len: length of buffer to allocate
116  *
117  * Allocates a buffer of size @len to be freed when processing the compound
118  * operation described in @argp finishes.
119  */
120 static void *
121 svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
122 {
123 	struct svcxdr_tmpbuf *tb;
124 
125 	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
126 	if (!tb)
127 		return NULL;
128 	tb->next = argp->to_free;
129 	argp->to_free = tb;
130 	return tb->buf;
131 }
132 
133 /*
134  * For xdr strings that need to be passed to other kernel api's
135  * as null-terminated strings.
136  *
137  * Note null-terminating in place usually isn't safe since the
138  * buffer might end on a page boundary.
139  */
140 static char *
141 svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
142 {
143 	char *p = svcxdr_tmpalloc(argp, len + 1);
144 
145 	if (!p)
146 		return NULL;
147 	memcpy(p, buf, len);
148 	p[len] = '\0';
149 	return p;
150 }
151 
152 static void *
153 svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, u32 len)
154 {
155 	__be32 *tmp;
156 
157 	/*
158 	 * The location of the decoded data item is stable,
159 	 * so @p is OK to use. This is the common case.
160 	 */
161 	if (p != argp->xdr->scratch.iov_base)
162 		return p;
163 
164 	tmp = svcxdr_tmpalloc(argp, len);
165 	if (!tmp)
166 		return NULL;
167 	memcpy(tmp, p, len);
168 	return tmp;
169 }
170 
171 /*
172  * NFSv4 basic data type decoders
173  */
174 
175 /*
176  * This helper handles variable-length opaques which belong to protocol
177  * elements that this implementation does not support.
178  */
179 static __be32
180 nfsd4_decode_ignored_string(struct nfsd4_compoundargs *argp, u32 maxlen)
181 {
182 	u32 len;
183 
184 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
185 		return nfserr_bad_xdr;
186 	if (maxlen && len > maxlen)
187 		return nfserr_bad_xdr;
188 	if (!xdr_inline_decode(argp->xdr, len))
189 		return nfserr_bad_xdr;
190 
191 	return nfs_ok;
192 }
193 
194 static __be32
195 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
196 {
197 	__be32 *p;
198 	u32 len;
199 
200 	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
201 		return nfserr_bad_xdr;
202 	if (len == 0 || len > NFS4_OPAQUE_LIMIT)
203 		return nfserr_bad_xdr;
204 	p = xdr_inline_decode(argp->xdr, len);
205 	if (!p)
206 		return nfserr_bad_xdr;
207 	o->data = svcxdr_savemem(argp, p, len);
208 	if (!o->data)
209 		return nfserr_jukebox;
210 	o->len = len;
211 
212 	return nfs_ok;
213 }
214 
215 static __be32
216 nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
217 {
218 	__be32 *p, status;
219 
220 	if (xdr_stream_decode_u32(argp->xdr, lenp) < 0)
221 		return nfserr_bad_xdr;
222 	p = xdr_inline_decode(argp->xdr, *lenp);
223 	if (!p)
224 		return nfserr_bad_xdr;
225 	status = check_filename((char *)p, *lenp);
226 	if (status)
227 		return status;
228 	*namp = svcxdr_savemem(argp, p, *lenp);
229 	if (!*namp)
230 		return nfserr_jukebox;
231 
232 	return nfs_ok;
233 }
234 
235 static __be32
236 nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
237 {
238 	__be32 *p;
239 
240 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
241 	if (!p)
242 		return nfserr_bad_xdr;
243 	p = xdr_decode_hyper(p, &tv->tv_sec);
244 	tv->tv_nsec = be32_to_cpup(p++);
245 	if (tv->tv_nsec >= (u32)1000000000)
246 		return nfserr_inval;
247 	return nfs_ok;
248 }
249 
250 static __be32
251 nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
252 {
253 	__be32 *p;
254 
255 	p = xdr_inline_decode(argp->xdr, NFS4_VERIFIER_SIZE);
256 	if (!p)
257 		return nfserr_bad_xdr;
258 	memcpy(verf->data, p, sizeof(verf->data));
259 	return nfs_ok;
260 }
261 
262 /**
263  * nfsd4_decode_bitmap4 - Decode an NFSv4 bitmap4
264  * @argp: NFSv4 compound argument structure
265  * @bmval: pointer to an array of u32's to decode into
266  * @bmlen: size of the @bmval array
267  *
268  * The server needs to return nfs_ok rather than nfserr_bad_xdr when
269  * encountering bitmaps containing bits it does not recognize. This
270  * includes bits in bitmap words past WORDn, where WORDn is the last
271  * bitmap WORD the implementation currently supports. Thus we are
272  * careful here to simply ignore bits in bitmap words that this
273  * implementation has yet to support explicitly.
274  *
275  * Return values:
276  *   %nfs_ok: @bmval populated successfully
277  *   %nfserr_bad_xdr: the encoded bitmap was invalid
278  */
279 static __be32
280 nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
281 {
282 	ssize_t status;
283 
284 	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
285 	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
286 }
287 
288 static __be32
289 nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
290 {
291 	__be32 *p, status;
292 	u32 length;
293 
294 	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
295 		return nfserr_bad_xdr;
296 	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
297 		return nfserr_bad_xdr;
298 	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
299 		return nfserr_bad_xdr;
300 
301 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
302 		return nfserr_bad_xdr;
303 	p = xdr_inline_decode(argp->xdr, length);
304 	if (!p)
305 		return nfserr_bad_xdr;
306 	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
307 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
308 		status = nfs_ok;
309 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
310 		status = nfsd_map_name_to_gid(argp->rqstp,
311 				(char *)p, length, &ace->who_gid);
312 	else
313 		status = nfsd_map_name_to_uid(argp->rqstp,
314 				(char *)p, length, &ace->who_uid);
315 
316 	return status;
317 }
318 
319 /* A counted array of nfsace4's */
320 static noinline __be32
321 nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
322 {
323 	struct nfs4_ace *ace;
324 	__be32 status;
325 	u32 count;
326 
327 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
328 		return nfserr_bad_xdr;
329 
330 	if (count > xdr_stream_remaining(argp->xdr) / 20)
331 		/*
332 		 * Even with 4-byte names there wouldn't be
333 		 * space for that many aces; something fishy is
334 		 * going on:
335 		 */
336 		return nfserr_fbig;
337 
338 	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
339 	if (*acl == NULL)
340 		return nfserr_jukebox;
341 
342 	(*acl)->naces = count;
343 	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
344 		status = nfsd4_decode_nfsace4(argp, ace);
345 		if (status)
346 			return status;
347 	}
348 
349 	return nfs_ok;
350 }
351 
352 static noinline __be32
353 nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
354 			    struct xdr_netobj *label)
355 {
356 	u32 lfs, pi, length;
357 	__be32 *p;
358 
359 	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
360 		return nfserr_bad_xdr;
361 	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
362 		return nfserr_bad_xdr;
363 
364 	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
365 		return nfserr_bad_xdr;
366 	if (length > NFS4_MAXLABELLEN)
367 		return nfserr_badlabel;
368 	p = xdr_inline_decode(argp->xdr, length);
369 	if (!p)
370 		return nfserr_bad_xdr;
371 	label->len = length;
372 	label->data = svcxdr_dupstr(argp, p, length);
373 	if (!label->data)
374 		return nfserr_jukebox;
375 
376 	return nfs_ok;
377 }
378 
379 static __be32
380 nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
381 		    struct iattr *iattr, struct nfs4_acl **acl,
382 		    struct xdr_netobj *label, int *umask)
383 {
384 	unsigned int starting_pos;
385 	u32 attrlist4_count;
386 	__be32 *p, status;
387 
388 	iattr->ia_valid = 0;
389 	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
390 	if (status)
391 		return nfserr_bad_xdr;
392 
393 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
394 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
395 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
396 		if (nfsd_attrs_supported(argp->minorversion, bmval))
397 			return nfserr_inval;
398 		return nfserr_attrnotsupp;
399 	}
400 
401 	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
402 		return nfserr_bad_xdr;
403 	starting_pos = xdr_stream_pos(argp->xdr);
404 
405 	if (bmval[0] & FATTR4_WORD0_SIZE) {
406 		u64 size;
407 
408 		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
409 			return nfserr_bad_xdr;
410 		iattr->ia_size = size;
411 		iattr->ia_valid |= ATTR_SIZE;
412 	}
413 	if (bmval[0] & FATTR4_WORD0_ACL) {
414 		status = nfsd4_decode_acl(argp, acl);
415 		if (status)
416 			return status;
417 	} else
418 		*acl = NULL;
419 	if (bmval[1] & FATTR4_WORD1_MODE) {
420 		u32 mode;
421 
422 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
423 			return nfserr_bad_xdr;
424 		iattr->ia_mode = mode;
425 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
426 		iattr->ia_valid |= ATTR_MODE;
427 	}
428 	if (bmval[1] & FATTR4_WORD1_OWNER) {
429 		u32 length;
430 
431 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
432 			return nfserr_bad_xdr;
433 		p = xdr_inline_decode(argp->xdr, length);
434 		if (!p)
435 			return nfserr_bad_xdr;
436 		status = nfsd_map_name_to_uid(argp->rqstp, (char *)p, length,
437 					      &iattr->ia_uid);
438 		if (status)
439 			return status;
440 		iattr->ia_valid |= ATTR_UID;
441 	}
442 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
443 		u32 length;
444 
445 		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
446 			return nfserr_bad_xdr;
447 		p = xdr_inline_decode(argp->xdr, length);
448 		if (!p)
449 			return nfserr_bad_xdr;
450 		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
451 					      &iattr->ia_gid);
452 		if (status)
453 			return status;
454 		iattr->ia_valid |= ATTR_GID;
455 	}
456 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
457 		u32 set_it;
458 
459 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
460 			return nfserr_bad_xdr;
461 		switch (set_it) {
462 		case NFS4_SET_TO_CLIENT_TIME:
463 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
464 			if (status)
465 				return status;
466 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
467 			break;
468 		case NFS4_SET_TO_SERVER_TIME:
469 			iattr->ia_valid |= ATTR_ATIME;
470 			break;
471 		default:
472 			return nfserr_bad_xdr;
473 		}
474 	}
475 	if (bmval[1] & FATTR4_WORD1_TIME_CREATE) {
476 		struct timespec64 ts;
477 
478 		/* No Linux filesystem supports setting this attribute. */
479 		bmval[1] &= ~FATTR4_WORD1_TIME_CREATE;
480 		status = nfsd4_decode_nfstime4(argp, &ts);
481 		if (status)
482 			return status;
483 	}
484 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
485 		u32 set_it;
486 
487 		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
488 			return nfserr_bad_xdr;
489 		switch (set_it) {
490 		case NFS4_SET_TO_CLIENT_TIME:
491 			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
492 			if (status)
493 				return status;
494 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
495 			break;
496 		case NFS4_SET_TO_SERVER_TIME:
497 			iattr->ia_valid |= ATTR_MTIME;
498 			break;
499 		default:
500 			return nfserr_bad_xdr;
501 		}
502 	}
503 	label->len = 0;
504 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
505 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
506 		status = nfsd4_decode_security_label(argp, label);
507 		if (status)
508 			return status;
509 	}
510 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
511 		u32 mode, mask;
512 
513 		if (!umask)
514 			return nfserr_bad_xdr;
515 		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
516 			return nfserr_bad_xdr;
517 		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
518 		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
519 			return nfserr_bad_xdr;
520 		*umask = mask & S_IRWXUGO;
521 		iattr->ia_valid |= ATTR_MODE;
522 	}
523 
524 	/* request sanity: did attrlist4 contain the expected number of words? */
525 	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
526 		return nfserr_bad_xdr;
527 
528 	return nfs_ok;
529 }
530 
531 static __be32
532 nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
533 {
534 	__be32 *p;
535 
536 	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
537 	if (!p)
538 		return nfserr_bad_xdr;
539 	sid->si_generation = be32_to_cpup(p++);
540 	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
541 	return nfs_ok;
542 }
543 
544 static __be32
545 nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
546 {
547 	__be32 *p;
548 
549 	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
550 	if (!p)
551 		return nfserr_bad_xdr;
552 	memcpy(clientid, p, sizeof(*clientid));
553 	return nfs_ok;
554 }
555 
556 static __be32
557 nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
558 			  clientid_t *clientid, struct xdr_netobj *owner)
559 {
560 	__be32 status;
561 
562 	status = nfsd4_decode_clientid4(argp, clientid);
563 	if (status)
564 		return status;
565 	return nfsd4_decode_opaque(argp, owner);
566 }
567 
568 #ifdef CONFIG_NFSD_PNFS
569 static __be32
570 nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
571 		       struct nfsd4_deviceid *devid)
572 {
573 	__be32 *p;
574 
575 	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
576 	if (!p)
577 		return nfserr_bad_xdr;
578 	memcpy(devid, p, sizeof(*devid));
579 	return nfs_ok;
580 }
581 
582 static __be32
583 nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
584 			   struct nfsd4_layoutcommit *lcp)
585 {
586 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
587 		return nfserr_bad_xdr;
588 	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
589 		return nfserr_bad_xdr;
590 	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
591 		return nfserr_bad_xdr;
592 
593 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
594 		return nfserr_bad_xdr;
595 	if (lcp->lc_up_len > 0) {
596 		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
597 		if (!lcp->lc_up_layout)
598 			return nfserr_bad_xdr;
599 	}
600 
601 	return nfs_ok;
602 }
603 
604 static __be32
605 nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
606 			   struct nfsd4_layoutreturn *lrp)
607 {
608 	__be32 status;
609 
610 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
611 		return nfserr_bad_xdr;
612 	switch (lrp->lr_return_type) {
613 	case RETURN_FILE:
614 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
615 			return nfserr_bad_xdr;
616 		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
617 			return nfserr_bad_xdr;
618 		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
619 		if (status)
620 			return status;
621 		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
622 			return nfserr_bad_xdr;
623 		if (lrp->lrf_body_len > 0) {
624 			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
625 			if (!lrp->lrf_body)
626 				return nfserr_bad_xdr;
627 		}
628 		break;
629 	case RETURN_FSID:
630 	case RETURN_ALL:
631 		lrp->lr_seg.offset = 0;
632 		lrp->lr_seg.length = NFS4_MAX_UINT64;
633 		break;
634 	default:
635 		return nfserr_bad_xdr;
636 	}
637 
638 	return nfs_ok;
639 }
640 
641 #endif /* CONFIG_NFSD_PNFS */
642 
643 static __be32
644 nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
645 			struct nfs4_sessionid *sessionid)
646 {
647 	__be32 *p;
648 
649 	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
650 	if (!p)
651 		return nfserr_bad_xdr;
652 	memcpy(sessionid->data, p, sizeof(sessionid->data));
653 	return nfs_ok;
654 }
655 
656 /* Defined in Appendix A of RFC 5531 */
657 static __be32
658 nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
659 			   struct nfsd4_cb_sec *cbs)
660 {
661 	u32 stamp, gidcount, uid, gid;
662 	__be32 *p, status;
663 
664 	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
665 		return nfserr_bad_xdr;
666 	/* machine name */
667 	status = nfsd4_decode_ignored_string(argp, 255);
668 	if (status)
669 		return status;
670 	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
671 		return nfserr_bad_xdr;
672 	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
673 		return nfserr_bad_xdr;
674 	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
675 		return nfserr_bad_xdr;
676 	if (gidcount > 16)
677 		return nfserr_bad_xdr;
678 	p = xdr_inline_decode(argp->xdr, gidcount << 2);
679 	if (!p)
680 		return nfserr_bad_xdr;
681 	if (cbs->flavor == (u32)(-1)) {
682 		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
683 
684 		kuid_t kuid = make_kuid(userns, uid);
685 		kgid_t kgid = make_kgid(userns, gid);
686 		if (uid_valid(kuid) && gid_valid(kgid)) {
687 			cbs->uid = kuid;
688 			cbs->gid = kgid;
689 			cbs->flavor = RPC_AUTH_UNIX;
690 		} else {
691 			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
692 		}
693 	}
694 
695 	return nfs_ok;
696 }
697 
698 static __be32
699 nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
700 			     struct nfsd4_cb_sec *cbs)
701 {
702 	__be32 status;
703 	u32 service;
704 
705 	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
706 
707 	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
708 		return nfserr_bad_xdr;
709 	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
710 		return nfserr_bad_xdr;
711 	/* gcbp_handle_from_server */
712 	status = nfsd4_decode_ignored_string(argp, 0);
713 	if (status)
714 		return status;
715 	/* gcbp_handle_from_client */
716 	status = nfsd4_decode_ignored_string(argp, 0);
717 	if (status)
718 		return status;
719 
720 	return nfs_ok;
721 }
722 
723 /* a counted array of callback_sec_parms4 items */
724 static __be32
725 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
726 {
727 	u32 i, secflavor, nr_secflavs;
728 	__be32 status;
729 
730 	/* callback_sec_params4 */
731 	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
732 		return nfserr_bad_xdr;
733 	if (nr_secflavs)
734 		cbs->flavor = (u32)(-1);
735 	else
736 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
737 		cbs->flavor = 0;
738 
739 	for (i = 0; i < nr_secflavs; ++i) {
740 		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
741 			return nfserr_bad_xdr;
742 		switch (secflavor) {
743 		case RPC_AUTH_NULL:
744 			/* void */
745 			if (cbs->flavor == (u32)(-1))
746 				cbs->flavor = RPC_AUTH_NULL;
747 			break;
748 		case RPC_AUTH_UNIX:
749 			status = nfsd4_decode_authsys_parms(argp, cbs);
750 			if (status)
751 				return status;
752 			break;
753 		case RPC_AUTH_GSS:
754 			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
755 			if (status)
756 				return status;
757 			break;
758 		default:
759 			return nfserr_inval;
760 		}
761 	}
762 
763 	return nfs_ok;
764 }
765 
766 
767 /*
768  * NFSv4 operation argument decoders
769  */
770 
771 static __be32
772 nfsd4_decode_access(struct nfsd4_compoundargs *argp,
773 		    union nfsd4_op_u *u)
774 {
775 	struct nfsd4_access *access = &u->access;
776 	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
777 		return nfserr_bad_xdr;
778 	return nfs_ok;
779 }
780 
781 static __be32
782 nfsd4_decode_close(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
783 {
784 	struct nfsd4_close *close = &u->close;
785 	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
786 		return nfserr_bad_xdr;
787 	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
788 }
789 
790 
791 static __be32
792 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
793 {
794 	struct nfsd4_commit *commit = &u->commit;
795 	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
796 		return nfserr_bad_xdr;
797 	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
798 		return nfserr_bad_xdr;
799 	memset(&commit->co_verf, 0, sizeof(commit->co_verf));
800 	return nfs_ok;
801 }
802 
803 static __be32
804 nfsd4_decode_create(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
805 {
806 	struct nfsd4_create *create = &u->create;
807 	__be32 *p, status;
808 
809 	memset(create, 0, sizeof(*create));
810 	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
811 		return nfserr_bad_xdr;
812 	switch (create->cr_type) {
813 	case NF4LNK:
814 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
815 			return nfserr_bad_xdr;
816 		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
817 		if (!p)
818 			return nfserr_bad_xdr;
819 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
820 		if (!create->cr_data)
821 			return nfserr_jukebox;
822 		break;
823 	case NF4BLK:
824 	case NF4CHR:
825 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
826 			return nfserr_bad_xdr;
827 		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
828 			return nfserr_bad_xdr;
829 		break;
830 	case NF4SOCK:
831 	case NF4FIFO:
832 	case NF4DIR:
833 	default:
834 		break;
835 	}
836 	status = nfsd4_decode_component4(argp, &create->cr_name,
837 					 &create->cr_namelen);
838 	if (status)
839 		return status;
840 	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
841 				    ARRAY_SIZE(create->cr_bmval),
842 				    &create->cr_iattr, &create->cr_acl,
843 				    &create->cr_label, &create->cr_umask);
844 	if (status)
845 		return status;
846 
847 	return nfs_ok;
848 }
849 
850 static inline __be32
851 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
852 {
853 	struct nfsd4_delegreturn *dr = &u->delegreturn;
854 	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
855 }
856 
857 static inline __be32
858 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
859 {
860 	struct nfsd4_getattr *getattr = &u->getattr;
861 	memset(getattr, 0, sizeof(*getattr));
862 	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
863 				    ARRAY_SIZE(getattr->ga_bmval));
864 }
865 
866 static __be32
867 nfsd4_decode_link(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
868 {
869 	struct nfsd4_link *link = &u->link;
870 	memset(link, 0, sizeof(*link));
871 	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
872 }
873 
874 static __be32
875 nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
876 				 struct nfsd4_lock *lock)
877 {
878 	__be32 status;
879 
880 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
881 		return nfserr_bad_xdr;
882 	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
883 	if (status)
884 		return status;
885 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
886 		return nfserr_bad_xdr;
887 	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
888 					 &lock->lk_new_owner);
889 }
890 
891 static __be32
892 nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
893 			       struct nfsd4_lock *lock)
894 {
895 	__be32 status;
896 
897 	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
898 	if (status)
899 		return status;
900 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
901 		return nfserr_bad_xdr;
902 
903 	return nfs_ok;
904 }
905 
906 static __be32
907 nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
908 {
909 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
910 		return nfserr_bad_xdr;
911 	if (lock->lk_is_new)
912 		return nfsd4_decode_open_to_lock_owner4(argp, lock);
913 	return nfsd4_decode_exist_lock_owner4(argp, lock);
914 }
915 
916 static __be32
917 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
918 {
919 	struct nfsd4_lock *lock = &u->lock;
920 	memset(lock, 0, sizeof(*lock));
921 	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
922 		return nfserr_bad_xdr;
923 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
924 		return nfserr_bad_xdr;
925 	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
926 		return nfserr_bad_xdr;
927 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
928 		return nfserr_bad_xdr;
929 	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
930 		return nfserr_bad_xdr;
931 	return nfsd4_decode_locker4(argp, lock);
932 }
933 
934 static __be32
935 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
936 {
937 	struct nfsd4_lockt *lockt = &u->lockt;
938 	memset(lockt, 0, sizeof(*lockt));
939 	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
940 		return nfserr_bad_xdr;
941 	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
942 		return nfserr_bad_xdr;
943 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
944 		return nfserr_bad_xdr;
945 	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
946 		return nfserr_bad_xdr;
947 	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
948 					 &lockt->lt_owner);
949 }
950 
951 static __be32
952 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
953 {
954 	struct nfsd4_locku *locku = &u->locku;
955 	__be32 status;
956 
957 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
958 		return nfserr_bad_xdr;
959 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
960 		return nfserr_bad_xdr;
961 	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
962 		return nfserr_bad_xdr;
963 	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
964 	if (status)
965 		return status;
966 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
967 		return nfserr_bad_xdr;
968 	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
969 		return nfserr_bad_xdr;
970 
971 	return nfs_ok;
972 }
973 
974 static __be32
975 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
976 {
977 	struct nfsd4_lookup *lookup = &u->lookup;
978 	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
979 }
980 
981 static __be32
982 nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
983 {
984 	__be32 status;
985 
986 	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
987 		return nfserr_bad_xdr;
988 	switch (open->op_createmode) {
989 	case NFS4_CREATE_UNCHECKED:
990 	case NFS4_CREATE_GUARDED:
991 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
992 					     ARRAY_SIZE(open->op_bmval),
993 					     &open->op_iattr, &open->op_acl,
994 					     &open->op_label, &open->op_umask);
995 		if (status)
996 			return status;
997 		break;
998 	case NFS4_CREATE_EXCLUSIVE:
999 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
1000 		if (status)
1001 			return status;
1002 		break;
1003 	case NFS4_CREATE_EXCLUSIVE4_1:
1004 		if (argp->minorversion < 1)
1005 			return nfserr_bad_xdr;
1006 		status = nfsd4_decode_verifier4(argp, &open->op_verf);
1007 		if (status)
1008 			return status;
1009 		status = nfsd4_decode_fattr4(argp, open->op_bmval,
1010 					     ARRAY_SIZE(open->op_bmval),
1011 					     &open->op_iattr, &open->op_acl,
1012 					     &open->op_label, &open->op_umask);
1013 		if (status)
1014 			return status;
1015 		break;
1016 	default:
1017 		return nfserr_bad_xdr;
1018 	}
1019 
1020 	return nfs_ok;
1021 }
1022 
1023 static __be32
1024 nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
1025 {
1026 	__be32 status;
1027 
1028 	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
1029 		return nfserr_bad_xdr;
1030 	switch (open->op_create) {
1031 	case NFS4_OPEN_NOCREATE:
1032 		break;
1033 	case NFS4_OPEN_CREATE:
1034 		status = nfsd4_decode_createhow4(argp, open);
1035 		if (status)
1036 			return status;
1037 		break;
1038 	default:
1039 		return nfserr_bad_xdr;
1040 	}
1041 
1042 	return nfs_ok;
1043 }
1044 
1045 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
1046 {
1047 	u32 w;
1048 
1049 	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
1050 		return nfserr_bad_xdr;
1051 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
1052 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
1053 	if (deleg_when)
1054 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
1055 
1056 	switch (w & NFS4_SHARE_ACCESS_MASK) {
1057 	case NFS4_SHARE_ACCESS_READ:
1058 	case NFS4_SHARE_ACCESS_WRITE:
1059 	case NFS4_SHARE_ACCESS_BOTH:
1060 		break;
1061 	default:
1062 		return nfserr_bad_xdr;
1063 	}
1064 	w &= ~NFS4_SHARE_ACCESS_MASK;
1065 	if (!w)
1066 		return nfs_ok;
1067 	if (!argp->minorversion)
1068 		return nfserr_bad_xdr;
1069 	switch (w & NFS4_SHARE_WANT_MASK) {
1070 	case NFS4_SHARE_WANT_NO_PREFERENCE:
1071 	case NFS4_SHARE_WANT_READ_DELEG:
1072 	case NFS4_SHARE_WANT_WRITE_DELEG:
1073 	case NFS4_SHARE_WANT_ANY_DELEG:
1074 	case NFS4_SHARE_WANT_NO_DELEG:
1075 	case NFS4_SHARE_WANT_CANCEL:
1076 		break;
1077 	default:
1078 		return nfserr_bad_xdr;
1079 	}
1080 	w &= ~NFS4_SHARE_WANT_MASK;
1081 	if (!w)
1082 		return nfs_ok;
1083 
1084 	if (!deleg_when)	/* open_downgrade */
1085 		return nfserr_inval;
1086 	switch (w) {
1087 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
1088 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
1089 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
1090 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
1091 		return nfs_ok;
1092 	}
1093 	return nfserr_bad_xdr;
1094 }
1095 
1096 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
1097 {
1098 	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
1099 		return nfserr_bad_xdr;
1100 	/* Note: unlike access bits, deny bits may be zero. */
1101 	if (*x & ~NFS4_SHARE_DENY_BOTH)
1102 		return nfserr_bad_xdr;
1103 
1104 	return nfs_ok;
1105 }
1106 
1107 static __be32
1108 nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
1109 			 struct nfsd4_open *open)
1110 {
1111 	__be32 status;
1112 
1113 	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
1114 		return nfserr_bad_xdr;
1115 	switch (open->op_claim_type) {
1116 	case NFS4_OPEN_CLAIM_NULL:
1117 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
1118 		status = nfsd4_decode_component4(argp, &open->op_fname,
1119 						 &open->op_fnamelen);
1120 		if (status)
1121 			return status;
1122 		break;
1123 	case NFS4_OPEN_CLAIM_PREVIOUS:
1124 		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
1125 			return nfserr_bad_xdr;
1126 		break;
1127 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
1128 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1129 		if (status)
1130 			return status;
1131 		status = nfsd4_decode_component4(argp, &open->op_fname,
1132 						 &open->op_fnamelen);
1133 		if (status)
1134 			return status;
1135 		break;
1136 	case NFS4_OPEN_CLAIM_FH:
1137 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1138 		if (argp->minorversion < 1)
1139 			return nfserr_bad_xdr;
1140 		/* void */
1141 		break;
1142 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1143 		if (argp->minorversion < 1)
1144 			return nfserr_bad_xdr;
1145 		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
1146 		if (status)
1147 			return status;
1148 		break;
1149 	default:
1150 		return nfserr_bad_xdr;
1151 	}
1152 
1153 	return nfs_ok;
1154 }
1155 
1156 static __be32
1157 nfsd4_decode_open(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1158 {
1159 	struct nfsd4_open *open = &u->open;
1160 	__be32 status;
1161 	u32 dummy;
1162 
1163 	memset(open, 0, sizeof(*open));
1164 
1165 	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
1166 		return nfserr_bad_xdr;
1167 	/* deleg_want is ignored */
1168 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
1169 					   &open->op_deleg_want, &dummy);
1170 	if (status)
1171 		return status;
1172 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
1173 	if (status)
1174 		return status;
1175 	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
1176 					   &open->op_owner);
1177 	if (status)
1178 		return status;
1179 	status = nfsd4_decode_openflag4(argp, open);
1180 	if (status)
1181 		return status;
1182 	return nfsd4_decode_open_claim4(argp, open);
1183 }
1184 
1185 static __be32
1186 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp,
1187 			  union nfsd4_op_u *u)
1188 {
1189 	struct nfsd4_open_confirm *open_conf = &u->open_confirm;
1190 	__be32 status;
1191 
1192 	if (argp->minorversion >= 1)
1193 		return nfserr_notsupp;
1194 
1195 	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
1196 	if (status)
1197 		return status;
1198 	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
1199 		return nfserr_bad_xdr;
1200 
1201 	memset(&open_conf->oc_resp_stateid, 0,
1202 	       sizeof(open_conf->oc_resp_stateid));
1203 	return nfs_ok;
1204 }
1205 
1206 static __be32
1207 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp,
1208 			    union nfsd4_op_u *u)
1209 {
1210 	struct nfsd4_open_downgrade *open_down = &u->open_downgrade;
1211 	__be32 status;
1212 
1213 	memset(open_down, 0, sizeof(*open_down));
1214 	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
1215 	if (status)
1216 		return status;
1217 	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
1218 		return nfserr_bad_xdr;
1219 	/* deleg_want is ignored */
1220 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1221 					   &open_down->od_deleg_want, NULL);
1222 	if (status)
1223 		return status;
1224 	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1225 }
1226 
1227 static __be32
1228 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1229 {
1230 	struct nfsd4_putfh *putfh = &u->putfh;
1231 	__be32 *p;
1232 
1233 	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
1234 		return nfserr_bad_xdr;
1235 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1236 		return nfserr_bad_xdr;
1237 	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
1238 	if (!p)
1239 		return nfserr_bad_xdr;
1240 	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
1241 	if (!putfh->pf_fhval)
1242 		return nfserr_jukebox;
1243 
1244 	putfh->no_verify = false;
1245 	return nfs_ok;
1246 }
1247 
1248 static __be32
1249 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
1250 {
1251 	if (argp->minorversion == 0)
1252 		return nfs_ok;
1253 	return nfserr_notsupp;
1254 }
1255 
1256 static __be32
1257 nfsd4_decode_read(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1258 {
1259 	struct nfsd4_read *read = &u->read;
1260 	__be32 status;
1261 
1262 	memset(read, 0, sizeof(*read));
1263 	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
1264 	if (status)
1265 		return status;
1266 	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
1267 		return nfserr_bad_xdr;
1268 	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
1269 		return nfserr_bad_xdr;
1270 
1271 	return nfs_ok;
1272 }
1273 
1274 static __be32
1275 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1276 {
1277 	struct nfsd4_readdir *readdir = &u->readdir;
1278 	__be32 status;
1279 
1280 	memset(readdir, 0, sizeof(*readdir));
1281 	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
1282 		return nfserr_bad_xdr;
1283 	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
1284 	if (status)
1285 		return status;
1286 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
1287 		return nfserr_bad_xdr;
1288 	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
1289 		return nfserr_bad_xdr;
1290 	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
1291 					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
1292 		return nfserr_bad_xdr;
1293 
1294 	return nfs_ok;
1295 }
1296 
1297 static __be32
1298 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1299 {
1300 	struct nfsd4_remove *remove = &u->remove;
1301 	memset(&remove->rm_cinfo, 0, sizeof(remove->rm_cinfo));
1302 	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
1303 }
1304 
1305 static __be32
1306 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1307 {
1308 	struct nfsd4_rename *rename = &u->rename;
1309 	__be32 status;
1310 
1311 	memset(rename, 0, sizeof(*rename));
1312 	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
1313 	if (status)
1314 		return status;
1315 	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
1316 }
1317 
1318 static __be32
1319 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1320 {
1321 	clientid_t *clientid = &u->renew;
1322 	return nfsd4_decode_clientid4(argp, clientid);
1323 }
1324 
1325 static __be32
1326 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1327 		     union nfsd4_op_u *u)
1328 {
1329 	struct nfsd4_secinfo *secinfo = &u->secinfo;
1330 	secinfo->si_exp = NULL;
1331 	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
1332 }
1333 
1334 static __be32
1335 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1336 {
1337 	struct nfsd4_setattr *setattr = &u->setattr;
1338 	__be32 status;
1339 
1340 	memset(setattr, 0, sizeof(*setattr));
1341 	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
1342 	if (status)
1343 		return status;
1344 	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
1345 				   ARRAY_SIZE(setattr->sa_bmval),
1346 				   &setattr->sa_iattr, &setattr->sa_acl,
1347 				   &setattr->sa_label, NULL);
1348 }
1349 
1350 static __be32
1351 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1352 {
1353 	struct nfsd4_setclientid *setclientid = &u->setclientid;
1354 	__be32 *p, status;
1355 
1356 	memset(setclientid, 0, sizeof(*setclientid));
1357 
1358 	if (argp->minorversion >= 1)
1359 		return nfserr_notsupp;
1360 
1361 	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
1362 	if (status)
1363 		return status;
1364 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1365 	if (status)
1366 		return status;
1367 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
1368 		return nfserr_bad_xdr;
1369 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
1370 		return nfserr_bad_xdr;
1371 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
1372 	if (!p)
1373 		return nfserr_bad_xdr;
1374 	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
1375 						setclientid->se_callback_netid_len);
1376 	if (!setclientid->se_callback_netid_val)
1377 		return nfserr_jukebox;
1378 
1379 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
1380 		return nfserr_bad_xdr;
1381 	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
1382 	if (!p)
1383 		return nfserr_bad_xdr;
1384 	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
1385 						setclientid->se_callback_addr_len);
1386 	if (!setclientid->se_callback_addr_val)
1387 		return nfserr_jukebox;
1388 	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
1389 		return nfserr_bad_xdr;
1390 
1391 	return nfs_ok;
1392 }
1393 
1394 static __be32
1395 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp,
1396 				 union nfsd4_op_u *u)
1397 {
1398 	struct nfsd4_setclientid_confirm *scd_c = &u->setclientid_confirm;
1399 	__be32 status;
1400 
1401 	if (argp->minorversion >= 1)
1402 		return nfserr_notsupp;
1403 
1404 	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
1405 	if (status)
1406 		return status;
1407 	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
1408 }
1409 
1410 /* Also used for NVERIFY */
1411 static __be32
1412 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1413 {
1414 	struct nfsd4_verify *verify = &u->verify;
1415 	__be32 *p, status;
1416 
1417 	memset(verify, 0, sizeof(*verify));
1418 
1419 	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
1420 				      ARRAY_SIZE(verify->ve_bmval));
1421 	if (status)
1422 		return status;
1423 
1424 	/* For convenience's sake, we compare raw xdr'd attributes in
1425 	 * nfsd4_proc_verify */
1426 
1427 	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
1428 		return nfserr_bad_xdr;
1429 	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
1430 	if (!p)
1431 		return nfserr_bad_xdr;
1432 	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
1433 	if (!verify->ve_attrval)
1434 		return nfserr_jukebox;
1435 
1436 	return nfs_ok;
1437 }
1438 
1439 static __be32
1440 nfsd4_decode_write(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1441 {
1442 	struct nfsd4_write *write = &u->write;
1443 	__be32 status;
1444 
1445 	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
1446 	if (status)
1447 		return status;
1448 	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
1449 		return nfserr_bad_xdr;
1450 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
1451 		return nfserr_bad_xdr;
1452 	if (write->wr_stable_how > NFS_FILE_SYNC)
1453 		return nfserr_bad_xdr;
1454 	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
1455 		return nfserr_bad_xdr;
1456 	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
1457 		return nfserr_bad_xdr;
1458 
1459 	write->wr_bytes_written = 0;
1460 	write->wr_how_written = 0;
1461 	memset(&write->wr_verifier, 0, sizeof(write->wr_verifier));
1462 	return nfs_ok;
1463 }
1464 
1465 static __be32
1466 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp,
1467 			       union nfsd4_op_u *u)
1468 {
1469 	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
1470 	__be32 status;
1471 
1472 	if (argp->minorversion >= 1)
1473 		return nfserr_notsupp;
1474 
1475 	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
1476 					   &rlockowner->rl_owner);
1477 	if (status)
1478 		return status;
1479 
1480 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1481 		return nfserr_inval;
1482 
1483 	return nfs_ok;
1484 }
1485 
1486 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp,
1487 					   union nfsd4_op_u *u)
1488 {
1489 	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
1490 	memset(bc, 0, sizeof(*bc));
1491 	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
1492 		return nfserr_bad_xdr;
1493 	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
1494 }
1495 
1496 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp,
1497 						union nfsd4_op_u *u)
1498 {
1499 	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
1500 	u32 use_conn_in_rdma_mode;
1501 	__be32 status;
1502 
1503 	memset(bcts, 0, sizeof(*bcts));
1504 	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
1505 	if (status)
1506 		return status;
1507 	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
1508 		return nfserr_bad_xdr;
1509 	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
1510 		return nfserr_bad_xdr;
1511 
1512 	return nfs_ok;
1513 }
1514 
1515 static __be32
1516 nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
1517 			       struct nfsd4_exchange_id *exid)
1518 {
1519 	__be32 status;
1520 
1521 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
1522 				      ARRAY_SIZE(exid->spo_must_enforce));
1523 	if (status)
1524 		return nfserr_bad_xdr;
1525 	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
1526 				      ARRAY_SIZE(exid->spo_must_allow));
1527 	if (status)
1528 		return nfserr_bad_xdr;
1529 
1530 	return nfs_ok;
1531 }
1532 
1533 /*
1534  * This implementation currently does not support SP4_SSV.
1535  * This decoder simply skips over these arguments.
1536  */
1537 static noinline __be32
1538 nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
1539 			  struct nfsd4_exchange_id *exid)
1540 {
1541 	u32 count, window, num_gss_handles;
1542 	__be32 status;
1543 
1544 	/* ssp_ops */
1545 	status = nfsd4_decode_state_protect_ops(argp, exid);
1546 	if (status)
1547 		return status;
1548 
1549 	/* ssp_hash_algs<> */
1550 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1551 		return nfserr_bad_xdr;
1552 	while (count--) {
1553 		status = nfsd4_decode_ignored_string(argp, 0);
1554 		if (status)
1555 			return status;
1556 	}
1557 
1558 	/* ssp_encr_algs<> */
1559 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1560 		return nfserr_bad_xdr;
1561 	while (count--) {
1562 		status = nfsd4_decode_ignored_string(argp, 0);
1563 		if (status)
1564 			return status;
1565 	}
1566 
1567 	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
1568 		return nfserr_bad_xdr;
1569 	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
1570 		return nfserr_bad_xdr;
1571 
1572 	return nfs_ok;
1573 }
1574 
1575 static __be32
1576 nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
1577 			      struct nfsd4_exchange_id *exid)
1578 {
1579 	__be32 status;
1580 
1581 	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
1582 		return nfserr_bad_xdr;
1583 	switch (exid->spa_how) {
1584 	case SP4_NONE:
1585 		break;
1586 	case SP4_MACH_CRED:
1587 		status = nfsd4_decode_state_protect_ops(argp, exid);
1588 		if (status)
1589 			return status;
1590 		break;
1591 	case SP4_SSV:
1592 		status = nfsd4_decode_ssv_sp_parms(argp, exid);
1593 		if (status)
1594 			return status;
1595 		break;
1596 	default:
1597 		return nfserr_bad_xdr;
1598 	}
1599 
1600 	return nfs_ok;
1601 }
1602 
1603 static __be32
1604 nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
1605 			  struct nfsd4_exchange_id *exid)
1606 {
1607 	__be32 status;
1608 	u32 count;
1609 
1610 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
1611 		return nfserr_bad_xdr;
1612 	switch (count) {
1613 	case 0:
1614 		break;
1615 	case 1:
1616 		/* Note that RFC 8881 places no length limit on
1617 		 * nii_domain, but this implementation permits no
1618 		 * more than NFS4_OPAQUE_LIMIT bytes */
1619 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1620 		if (status)
1621 			return status;
1622 		/* Note that RFC 8881 places no length limit on
1623 		 * nii_name, but this implementation permits no
1624 		 * more than NFS4_OPAQUE_LIMIT bytes */
1625 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1626 		if (status)
1627 			return status;
1628 		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
1629 		if (status)
1630 			return status;
1631 		break;
1632 	default:
1633 		return nfserr_bad_xdr;
1634 	}
1635 
1636 	return nfs_ok;
1637 }
1638 
1639 static __be32
1640 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1641 			 union nfsd4_op_u *u)
1642 {
1643 	struct nfsd4_exchange_id *exid = &u->exchange_id;
1644 	__be32 status;
1645 
1646 	memset(exid, 0, sizeof(*exid));
1647 	status = nfsd4_decode_verifier4(argp, &exid->verifier);
1648 	if (status)
1649 		return status;
1650 	status = nfsd4_decode_opaque(argp, &exid->clname);
1651 	if (status)
1652 		return status;
1653 	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
1654 		return nfserr_bad_xdr;
1655 	status = nfsd4_decode_state_protect4_a(argp, exid);
1656 	if (status)
1657 		return status;
1658 	return nfsd4_decode_nfs_impl_id4(argp, exid);
1659 }
1660 
1661 static __be32
1662 nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
1663 			    struct nfsd4_channel_attrs *ca)
1664 {
1665 	__be32 *p;
1666 
1667 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
1668 	if (!p)
1669 		return nfserr_bad_xdr;
1670 
1671 	/* headerpadsz is ignored */
1672 	p++;
1673 	ca->maxreq_sz = be32_to_cpup(p++);
1674 	ca->maxresp_sz = be32_to_cpup(p++);
1675 	ca->maxresp_cached = be32_to_cpup(p++);
1676 	ca->maxops = be32_to_cpup(p++);
1677 	ca->maxreqs = be32_to_cpup(p++);
1678 	ca->nr_rdma_attrs = be32_to_cpup(p);
1679 	switch (ca->nr_rdma_attrs) {
1680 	case 0:
1681 		break;
1682 	case 1:
1683 		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
1684 			return nfserr_bad_xdr;
1685 		break;
1686 	default:
1687 		return nfserr_bad_xdr;
1688 	}
1689 
1690 	return nfs_ok;
1691 }
1692 
1693 static __be32
1694 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1695 			    union nfsd4_op_u *u)
1696 {
1697 	struct nfsd4_create_session *sess = &u->create_session;
1698 	__be32 status;
1699 
1700 	memset(sess, 0, sizeof(*sess));
1701 	status = nfsd4_decode_clientid4(argp, &sess->clientid);
1702 	if (status)
1703 		return status;
1704 	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
1705 		return nfserr_bad_xdr;
1706 	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
1707 		return nfserr_bad_xdr;
1708 	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
1709 	if (status)
1710 		return status;
1711 	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
1712 	if (status)
1713 		return status;
1714 	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
1715 		return nfserr_bad_xdr;
1716 	return nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1717 }
1718 
1719 static __be32
1720 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1721 			     union nfsd4_op_u *u)
1722 {
1723 	struct nfsd4_destroy_session *destroy_session = &u->destroy_session;
1724 	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
1725 }
1726 
1727 static __be32
1728 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1729 			  union nfsd4_op_u *u)
1730 {
1731 	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
1732 	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
1733 }
1734 
1735 #ifdef CONFIG_NFSD_PNFS
1736 static __be32
1737 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1738 		union nfsd4_op_u *u)
1739 {
1740 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
1741 	__be32 status;
1742 
1743 	memset(gdev, 0, sizeof(*gdev));
1744 	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
1745 	if (status)
1746 		return status;
1747 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
1748 		return nfserr_bad_xdr;
1749 	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
1750 		return nfserr_bad_xdr;
1751 	if (xdr_stream_decode_uint32_array(argp->xdr,
1752 					   &gdev->gd_notify_types, 1) < 0)
1753 		return nfserr_bad_xdr;
1754 
1755 	return nfs_ok;
1756 }
1757 
1758 static __be32
1759 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1760 			  union nfsd4_op_u *u)
1761 {
1762 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
1763 	__be32 *p, status;
1764 
1765 	memset(lcp, 0, sizeof(*lcp));
1766 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
1767 		return nfserr_bad_xdr;
1768 	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
1769 		return nfserr_bad_xdr;
1770 	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
1771 		return nfserr_bad_xdr;
1772 	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
1773 	if (status)
1774 		return status;
1775 	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
1776 		return nfserr_bad_xdr;
1777 	if (lcp->lc_newoffset) {
1778 		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
1779 			return nfserr_bad_xdr;
1780 	} else
1781 		lcp->lc_last_wr = 0;
1782 	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
1783 	if (!p)
1784 		return nfserr_bad_xdr;
1785 	if (xdr_item_is_present(p)) {
1786 		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
1787 		if (status)
1788 			return status;
1789 	} else {
1790 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1791 	}
1792 	return nfsd4_decode_layoutupdate4(argp, lcp);
1793 }
1794 
1795 static __be32
1796 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1797 		union nfsd4_op_u *u)
1798 {
1799 	struct nfsd4_layoutget *lgp = &u->layoutget;
1800 	__be32 status;
1801 
1802 	memset(lgp, 0, sizeof(*lgp));
1803 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
1804 		return nfserr_bad_xdr;
1805 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
1806 		return nfserr_bad_xdr;
1807 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
1808 		return nfserr_bad_xdr;
1809 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
1810 		return nfserr_bad_xdr;
1811 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
1812 		return nfserr_bad_xdr;
1813 	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
1814 		return nfserr_bad_xdr;
1815 	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
1816 	if (status)
1817 		return status;
1818 	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
1819 		return nfserr_bad_xdr;
1820 
1821 	return nfs_ok;
1822 }
1823 
1824 static __be32
1825 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1826 		union nfsd4_op_u *u)
1827 {
1828 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
1829 	memset(lrp, 0, sizeof(*lrp));
1830 	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
1831 		return nfserr_bad_xdr;
1832 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
1833 		return nfserr_bad_xdr;
1834 	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
1835 		return nfserr_bad_xdr;
1836 	return nfsd4_decode_layoutreturn4(argp, lrp);
1837 }
1838 #endif /* CONFIG_NFSD_PNFS */
1839 
1840 static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1841 					   union nfsd4_op_u *u)
1842 {
1843 	struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name;
1844 	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
1845 		return nfserr_bad_xdr;
1846 
1847 	sin->sin_exp = NULL;
1848 	return nfs_ok;
1849 }
1850 
1851 static __be32
1852 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1853 		      union nfsd4_op_u *u)
1854 {
1855 	struct nfsd4_sequence *seq = &u->sequence;
1856 	__be32 *p, status;
1857 
1858 	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
1859 	if (status)
1860 		return status;
1861 	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
1862 	if (!p)
1863 		return nfserr_bad_xdr;
1864 	seq->seqid = be32_to_cpup(p++);
1865 	seq->slotid = be32_to_cpup(p++);
1866 	seq->maxslots = be32_to_cpup(p++);
1867 	seq->cachethis = be32_to_cpup(p);
1868 
1869 	seq->status_flags = 0;
1870 	return nfs_ok;
1871 }
1872 
1873 static __be32
1874 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp,
1875 			  union nfsd4_op_u *u)
1876 {
1877 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
1878 	struct nfsd4_test_stateid_id *stateid;
1879 	__be32 status;
1880 	u32 i;
1881 
1882 	memset(test_stateid, 0, sizeof(*test_stateid));
1883 	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
1884 		return nfserr_bad_xdr;
1885 
1886 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1887 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1888 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1889 		if (!stateid)
1890 			return nfserr_jukebox;
1891 		INIT_LIST_HEAD(&stateid->ts_id_list);
1892 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1893 		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
1894 		if (status)
1895 			return status;
1896 	}
1897 
1898 	return nfs_ok;
1899 }
1900 
1901 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
1902 					    union nfsd4_op_u *u)
1903 {
1904 	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
1905 	return nfsd4_decode_clientid4(argp, &dc->clientid);
1906 }
1907 
1908 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
1909 					    union nfsd4_op_u *u)
1910 {
1911 	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
1912 	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
1913 		return nfserr_bad_xdr;
1914 	return nfs_ok;
1915 }
1916 
1917 static __be32
1918 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1919 		       union nfsd4_op_u *u)
1920 {
1921 	struct nfsd4_fallocate *fallocate = &u->allocate;
1922 	__be32 status;
1923 
1924 	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
1925 	if (status)
1926 		return status;
1927 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
1928 		return nfserr_bad_xdr;
1929 	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
1930 		return nfserr_bad_xdr;
1931 
1932 	return nfs_ok;
1933 }
1934 
1935 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1936 				      struct nl4_server *ns)
1937 {
1938 	struct nfs42_netaddr *naddr;
1939 	__be32 *p;
1940 
1941 	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
1942 		return nfserr_bad_xdr;
1943 
1944 	/* currently support for 1 inter-server source server */
1945 	switch (ns->nl4_type) {
1946 	case NL4_NETADDR:
1947 		naddr = &ns->u.nl4_addr;
1948 
1949 		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
1950 			return nfserr_bad_xdr;
1951 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1952 			return nfserr_bad_xdr;
1953 
1954 		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
1955 		if (!p)
1956 			return nfserr_bad_xdr;
1957 		memcpy(naddr->netid, p, naddr->netid_len);
1958 
1959 		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
1960 			return nfserr_bad_xdr;
1961 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1962 			return nfserr_bad_xdr;
1963 
1964 		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
1965 		if (!p)
1966 			return nfserr_bad_xdr;
1967 		memcpy(naddr->addr, p, naddr->addr_len);
1968 		break;
1969 	default:
1970 		return nfserr_bad_xdr;
1971 	}
1972 
1973 	return nfs_ok;
1974 }
1975 
1976 static __be32
1977 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
1978 {
1979 	struct nfsd4_copy *copy = &u->copy;
1980 	u32 consecutive, i, count, sync;
1981 	struct nl4_server *ns_dummy;
1982 	__be32 status;
1983 
1984 	memset(copy, 0, sizeof(*copy));
1985 	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
1986 	if (status)
1987 		return status;
1988 	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
1989 	if (status)
1990 		return status;
1991 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
1992 		return nfserr_bad_xdr;
1993 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
1994 		return nfserr_bad_xdr;
1995 	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
1996 		return nfserr_bad_xdr;
1997 	/* ca_consecutive: we always do consecutive copies */
1998 	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
1999 		return nfserr_bad_xdr;
2000 	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
2001 		return nfserr_bad_xdr;
2002 	nfsd4_copy_set_sync(copy, sync);
2003 
2004 	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
2005 		return nfserr_bad_xdr;
2006 	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
2007 	if (copy->cp_src == NULL)
2008 		return nfserr_jukebox;
2009 	if (count == 0) { /* intra-server copy */
2010 		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
2011 		return nfs_ok;
2012 	}
2013 
2014 	/* decode all the supplied server addresses but use only the first */
2015 	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
2016 	if (status)
2017 		return status;
2018 
2019 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
2020 	if (ns_dummy == NULL)
2021 		return nfserr_jukebox;
2022 	for (i = 0; i < count - 1; i++) {
2023 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
2024 		if (status) {
2025 			kfree(ns_dummy);
2026 			return status;
2027 		}
2028 	}
2029 	kfree(ns_dummy);
2030 
2031 	return nfs_ok;
2032 }
2033 
2034 static __be32
2035 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
2036 			 union nfsd4_op_u *u)
2037 {
2038 	struct nfsd4_copy_notify *cn = &u->copy_notify;
2039 	__be32 status;
2040 
2041 	memset(cn, 0, sizeof(*cn));
2042 	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
2043 	if (cn->cpn_src == NULL)
2044 		return nfserr_jukebox;
2045 	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
2046 	if (cn->cpn_dst == NULL)
2047 		return nfserr_jukebox;
2048 
2049 	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
2050 	if (status)
2051 		return status;
2052 	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
2053 }
2054 
2055 static __be32
2056 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
2057 			    union nfsd4_op_u *u)
2058 {
2059 	struct nfsd4_offload_status *os = &u->offload_status;
2060 	os->count = 0;
2061 	os->status = 0;
2062 	return nfsd4_decode_stateid4(argp, &os->stateid);
2063 }
2064 
2065 static __be32
2066 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2067 {
2068 	struct nfsd4_seek *seek = &u->seek;
2069 	__be32 status;
2070 
2071 	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
2072 	if (status)
2073 		return status;
2074 	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
2075 		return nfserr_bad_xdr;
2076 	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
2077 		return nfserr_bad_xdr;
2078 
2079 	seek->seek_eof = 0;
2080 	seek->seek_pos = 0;
2081 	return nfs_ok;
2082 }
2083 
2084 static __be32
2085 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
2086 {
2087 	struct nfsd4_clone *clone = &u->clone;
2088 	__be32 status;
2089 
2090 	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
2091 	if (status)
2092 		return status;
2093 	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
2094 	if (status)
2095 		return status;
2096 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
2097 		return nfserr_bad_xdr;
2098 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
2099 		return nfserr_bad_xdr;
2100 	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
2101 		return nfserr_bad_xdr;
2102 
2103 	return nfs_ok;
2104 }
2105 
2106 /*
2107  * XDR data that is more than PAGE_SIZE in size is normally part of a
2108  * read or write. However, the size of extended attributes is limited
2109  * by the maximum request size, and then further limited by the underlying
2110  * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
2111  * is 64k). Since there is no kvec- or page-based interface to xattrs,
2112  * and we're not dealing with contiguous pages, we need to do some copying.
2113  */
2114 
2115 /*
2116  * Decode data into buffer.
2117  */
2118 static __be32
2119 nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
2120 		       char **bufp, u32 buflen)
2121 {
2122 	struct page **pages = xdr->pages;
2123 	struct kvec *head = xdr->head;
2124 	char *tmp, *dp;
2125 	u32 len;
2126 
2127 	if (buflen <= head->iov_len) {
2128 		/*
2129 		 * We're in luck, the head has enough space. Just return
2130 		 * the head, no need for copying.
2131 		 */
2132 		*bufp = head->iov_base;
2133 		return 0;
2134 	}
2135 
2136 	tmp = svcxdr_tmpalloc(argp, buflen);
2137 	if (tmp == NULL)
2138 		return nfserr_jukebox;
2139 
2140 	dp = tmp;
2141 	memcpy(dp, head->iov_base, head->iov_len);
2142 	buflen -= head->iov_len;
2143 	dp += head->iov_len;
2144 
2145 	while (buflen > 0) {
2146 		len = min_t(u32, buflen, PAGE_SIZE);
2147 		memcpy(dp, page_address(*pages), len);
2148 
2149 		buflen -= len;
2150 		dp += len;
2151 		pages++;
2152 	}
2153 
2154 	*bufp = tmp;
2155 	return 0;
2156 }
2157 
2158 /*
2159  * Get a user extended attribute name from the XDR buffer.
2160  * It will not have the "user." prefix, so prepend it.
2161  * Lastly, check for nul characters in the name.
2162  */
2163 static __be32
2164 nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
2165 {
2166 	char *name, *sp, *dp;
2167 	u32 namelen, cnt;
2168 	__be32 *p;
2169 
2170 	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
2171 		return nfserr_bad_xdr;
2172 	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
2173 		return nfserr_nametoolong;
2174 	if (namelen == 0)
2175 		return nfserr_bad_xdr;
2176 	p = xdr_inline_decode(argp->xdr, namelen);
2177 	if (!p)
2178 		return nfserr_bad_xdr;
2179 	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
2180 	if (!name)
2181 		return nfserr_jukebox;
2182 	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
2183 
2184 	/*
2185 	 * Copy the extended attribute name over while checking for 0
2186 	 * characters.
2187 	 */
2188 	sp = (char *)p;
2189 	dp = name + XATTR_USER_PREFIX_LEN;
2190 	cnt = namelen;
2191 
2192 	while (cnt-- > 0) {
2193 		if (*sp == '\0')
2194 			return nfserr_bad_xdr;
2195 		*dp++ = *sp++;
2196 	}
2197 	*dp = '\0';
2198 
2199 	*namep = name;
2200 
2201 	return nfs_ok;
2202 }
2203 
2204 /*
2205  * A GETXATTR op request comes without a length specifier. We just set the
2206  * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
2207  * channel reply size. nfsd_getxattr will probe the length of the xattr,
2208  * check it against getxa_len, and allocate + return the value.
2209  */
2210 static __be32
2211 nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
2212 		      union nfsd4_op_u *u)
2213 {
2214 	struct nfsd4_getxattr *getxattr = &u->getxattr;
2215 	__be32 status;
2216 	u32 maxcount;
2217 
2218 	memset(getxattr, 0, sizeof(*getxattr));
2219 	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
2220 	if (status)
2221 		return status;
2222 
2223 	maxcount = svc_max_payload(argp->rqstp);
2224 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2225 
2226 	getxattr->getxa_len = maxcount;
2227 	return nfs_ok;
2228 }
2229 
2230 static __be32
2231 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
2232 		      union nfsd4_op_u *u)
2233 {
2234 	struct nfsd4_setxattr *setxattr = &u->setxattr;
2235 	u32 flags, maxcount, size;
2236 	__be32 status;
2237 
2238 	memset(setxattr, 0, sizeof(*setxattr));
2239 
2240 	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
2241 		return nfserr_bad_xdr;
2242 
2243 	if (flags > SETXATTR4_REPLACE)
2244 		return nfserr_inval;
2245 	setxattr->setxa_flags = flags;
2246 
2247 	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
2248 	if (status)
2249 		return status;
2250 
2251 	maxcount = svc_max_payload(argp->rqstp);
2252 	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
2253 
2254 	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
2255 		return nfserr_bad_xdr;
2256 	if (size > maxcount)
2257 		return nfserr_xattr2big;
2258 
2259 	setxattr->setxa_len = size;
2260 	if (size > 0) {
2261 		struct xdr_buf payload;
2262 
2263 		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
2264 			return nfserr_bad_xdr;
2265 		status = nfsd4_vbuf_from_vector(argp, &payload,
2266 						&setxattr->setxa_buf, size);
2267 	}
2268 
2269 	return nfs_ok;
2270 }
2271 
2272 static __be32
2273 nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
2274 			union nfsd4_op_u *u)
2275 {
2276 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
2277 	u32 maxcount;
2278 
2279 	memset(listxattrs, 0, sizeof(*listxattrs));
2280 
2281 	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
2282 		return nfserr_bad_xdr;
2283 
2284 	/*
2285 	 * If the cookie  is too large to have even one user.x attribute
2286 	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
2287 	 */
2288 	if (listxattrs->lsxa_cookie >=
2289 	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
2290 		return nfserr_badcookie;
2291 
2292 	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
2293 		return nfserr_bad_xdr;
2294 	if (maxcount < 8)
2295 		/* Always need at least 2 words (length and one character) */
2296 		return nfserr_inval;
2297 
2298 	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
2299 	listxattrs->lsxa_maxcount = maxcount;
2300 
2301 	return nfs_ok;
2302 }
2303 
2304 static __be32
2305 nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
2306 			 union nfsd4_op_u *u)
2307 {
2308 	struct nfsd4_removexattr *removexattr = &u->removexattr;
2309 	memset(removexattr, 0, sizeof(*removexattr));
2310 	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
2311 }
2312 
2313 static __be32
2314 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2315 {
2316 	return nfs_ok;
2317 }
2318 
2319 static __be32
2320 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
2321 {
2322 	return nfserr_notsupp;
2323 }
2324 
2325 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u);
2326 
2327 static const nfsd4_dec nfsd4_dec_ops[] = {
2328 	[OP_ACCESS]		= nfsd4_decode_access,
2329 	[OP_CLOSE]		= nfsd4_decode_close,
2330 	[OP_COMMIT]		= nfsd4_decode_commit,
2331 	[OP_CREATE]		= nfsd4_decode_create,
2332 	[OP_DELEGPURGE]		= nfsd4_decode_notsupp,
2333 	[OP_DELEGRETURN]	= nfsd4_decode_delegreturn,
2334 	[OP_GETATTR]		= nfsd4_decode_getattr,
2335 	[OP_GETFH]		= nfsd4_decode_noop,
2336 	[OP_LINK]		= nfsd4_decode_link,
2337 	[OP_LOCK]		= nfsd4_decode_lock,
2338 	[OP_LOCKT]		= nfsd4_decode_lockt,
2339 	[OP_LOCKU]		= nfsd4_decode_locku,
2340 	[OP_LOOKUP]		= nfsd4_decode_lookup,
2341 	[OP_LOOKUPP]		= nfsd4_decode_noop,
2342 	[OP_NVERIFY]		= nfsd4_decode_verify,
2343 	[OP_OPEN]		= nfsd4_decode_open,
2344 	[OP_OPENATTR]		= nfsd4_decode_notsupp,
2345 	[OP_OPEN_CONFIRM]	= nfsd4_decode_open_confirm,
2346 	[OP_OPEN_DOWNGRADE]	= nfsd4_decode_open_downgrade,
2347 	[OP_PUTFH]		= nfsd4_decode_putfh,
2348 	[OP_PUTPUBFH]		= nfsd4_decode_putpubfh,
2349 	[OP_PUTROOTFH]		= nfsd4_decode_noop,
2350 	[OP_READ]		= nfsd4_decode_read,
2351 	[OP_READDIR]		= nfsd4_decode_readdir,
2352 	[OP_READLINK]		= nfsd4_decode_noop,
2353 	[OP_REMOVE]		= nfsd4_decode_remove,
2354 	[OP_RENAME]		= nfsd4_decode_rename,
2355 	[OP_RENEW]		= nfsd4_decode_renew,
2356 	[OP_RESTOREFH]		= nfsd4_decode_noop,
2357 	[OP_SAVEFH]		= nfsd4_decode_noop,
2358 	[OP_SECINFO]		= nfsd4_decode_secinfo,
2359 	[OP_SETATTR]		= nfsd4_decode_setattr,
2360 	[OP_SETCLIENTID]	= nfsd4_decode_setclientid,
2361 	[OP_SETCLIENTID_CONFIRM] = nfsd4_decode_setclientid_confirm,
2362 	[OP_VERIFY]		= nfsd4_decode_verify,
2363 	[OP_WRITE]		= nfsd4_decode_write,
2364 	[OP_RELEASE_LOCKOWNER]	= nfsd4_decode_release_lockowner,
2365 
2366 	/* new operations for NFSv4.1 */
2367 	[OP_BACKCHANNEL_CTL]	= nfsd4_decode_backchannel_ctl,
2368 	[OP_BIND_CONN_TO_SESSION] = nfsd4_decode_bind_conn_to_session,
2369 	[OP_EXCHANGE_ID]	= nfsd4_decode_exchange_id,
2370 	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
2371 	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
2372 	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
2373 	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_notsupp,
2374 #ifdef CONFIG_NFSD_PNFS
2375 	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
2376 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2377 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_layoutcommit,
2378 	[OP_LAYOUTGET]		= nfsd4_decode_layoutget,
2379 	[OP_LAYOUTRETURN]	= nfsd4_decode_layoutreturn,
2380 #else
2381 	[OP_GETDEVICEINFO]	= nfsd4_decode_notsupp,
2382 	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
2383 	[OP_LAYOUTCOMMIT]	= nfsd4_decode_notsupp,
2384 	[OP_LAYOUTGET]		= nfsd4_decode_notsupp,
2385 	[OP_LAYOUTRETURN]	= nfsd4_decode_notsupp,
2386 #endif
2387 	[OP_SECINFO_NO_NAME]	= nfsd4_decode_secinfo_no_name,
2388 	[OP_SEQUENCE]		= nfsd4_decode_sequence,
2389 	[OP_SET_SSV]		= nfsd4_decode_notsupp,
2390 	[OP_TEST_STATEID]	= nfsd4_decode_test_stateid,
2391 	[OP_WANT_DELEGATION]	= nfsd4_decode_notsupp,
2392 	[OP_DESTROY_CLIENTID]	= nfsd4_decode_destroy_clientid,
2393 	[OP_RECLAIM_COMPLETE]	= nfsd4_decode_reclaim_complete,
2394 
2395 	/* new operations for NFSv4.2 */
2396 	[OP_ALLOCATE]		= nfsd4_decode_fallocate,
2397 	[OP_COPY]		= nfsd4_decode_copy,
2398 	[OP_COPY_NOTIFY]	= nfsd4_decode_copy_notify,
2399 	[OP_DEALLOCATE]		= nfsd4_decode_fallocate,
2400 	[OP_IO_ADVISE]		= nfsd4_decode_notsupp,
2401 	[OP_LAYOUTERROR]	= nfsd4_decode_notsupp,
2402 	[OP_LAYOUTSTATS]	= nfsd4_decode_notsupp,
2403 	[OP_OFFLOAD_CANCEL]	= nfsd4_decode_offload_status,
2404 	[OP_OFFLOAD_STATUS]	= nfsd4_decode_offload_status,
2405 	[OP_READ_PLUS]		= nfsd4_decode_read,
2406 	[OP_SEEK]		= nfsd4_decode_seek,
2407 	[OP_WRITE_SAME]		= nfsd4_decode_notsupp,
2408 	[OP_CLONE]		= nfsd4_decode_clone,
2409 	/* RFC 8276 extended atributes operations */
2410 	[OP_GETXATTR]		= nfsd4_decode_getxattr,
2411 	[OP_SETXATTR]		= nfsd4_decode_setxattr,
2412 	[OP_LISTXATTRS]		= nfsd4_decode_listxattrs,
2413 	[OP_REMOVEXATTR]	= nfsd4_decode_removexattr,
2414 };
2415 
2416 static inline bool
2417 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
2418 {
2419 	if (op->opnum < FIRST_NFS4_OP)
2420 		return false;
2421 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
2422 		return false;
2423 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
2424 		return false;
2425 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
2426 		return false;
2427 	return true;
2428 }
2429 
2430 static bool
2431 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
2432 {
2433 	struct nfsd4_op *op;
2434 	bool cachethis = false;
2435 	int auth_slack= argp->rqstp->rq_auth_slack;
2436 	int max_reply = auth_slack + 8; /* opcnt, status */
2437 	int readcount = 0;
2438 	int readbytes = 0;
2439 	__be32 *p;
2440 	int i;
2441 
2442 	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
2443 		return false;
2444 	max_reply += XDR_UNIT;
2445 	argp->tag = NULL;
2446 	if (unlikely(argp->taglen)) {
2447 		if (argp->taglen > NFSD4_MAX_TAGLEN)
2448 			return false;
2449 		p = xdr_inline_decode(argp->xdr, argp->taglen);
2450 		if (!p)
2451 			return false;
2452 		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
2453 		if (!argp->tag)
2454 			return false;
2455 		max_reply += xdr_align_size(argp->taglen);
2456 	}
2457 
2458 	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
2459 		return false;
2460 	if (xdr_stream_decode_u32(argp->xdr, &argp->client_opcnt) < 0)
2461 		return false;
2462 	argp->opcnt = min_t(u32, argp->client_opcnt,
2463 			    NFSD_MAX_OPS_PER_COMPOUND);
2464 
2465 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2466 		argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops));
2467 		if (!argp->ops) {
2468 			argp->ops = argp->iops;
2469 			return false;
2470 		}
2471 	}
2472 
2473 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2474 		argp->opcnt = 0;
2475 
2476 	for (i = 0; i < argp->opcnt; i++) {
2477 		op = &argp->ops[i];
2478 		op->replay = NULL;
2479 		op->opdesc = NULL;
2480 
2481 		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
2482 			return false;
2483 		if (nfsd4_opnum_in_range(argp, op)) {
2484 			op->opdesc = OPDESC(op);
2485 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2486 			if (op->status != nfs_ok)
2487 				trace_nfsd_compound_decode_err(argp->rqstp,
2488 							       argp->opcnt, i,
2489 							       op->opnum,
2490 							       op->status);
2491 		} else {
2492 			op->opnum = OP_ILLEGAL;
2493 			op->status = nfserr_op_illegal;
2494 		}
2495 
2496 		/*
2497 		 * We'll try to cache the result in the DRC if any one
2498 		 * op in the compound wants to be cached:
2499 		 */
2500 		cachethis |= nfsd4_cache_this_op(op);
2501 
2502 		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
2503 			readcount++;
2504 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2505 		} else
2506 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2507 		/*
2508 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2509 		 * (Special case because it will just skip encoding this
2510 		 * if it runs out of xdr buffer space, and it is the only
2511 		 * operation that behaves this way.)
2512 		 */
2513 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2514 			max_reply += NFS4_OPAQUE_LIMIT;
2515 
2516 		if (op->status) {
2517 			argp->opcnt = i+1;
2518 			break;
2519 		}
2520 	}
2521 	/* Sessions make the DRC unnecessary: */
2522 	if (argp->minorversion)
2523 		cachethis = false;
2524 	svc_reserve(argp->rqstp, max_reply + readbytes);
2525 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2526 
2527 	argp->splice_ok = nfsd_read_splice_ok(argp->rqstp);
2528 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2529 		argp->splice_ok = false;
2530 
2531 	return true;
2532 }
2533 
2534 static __be32 nfsd4_encode_nfs_fh4(struct xdr_stream *xdr,
2535 				   struct knfsd_fh *fh_handle)
2536 {
2537 	return nfsd4_encode_opaque(xdr, fh_handle->fh_raw, fh_handle->fh_size);
2538 }
2539 
2540 /* This is a frequently-encoded type; open-coded for speed */
2541 static __be32 nfsd4_encode_nfstime4(struct xdr_stream *xdr,
2542 				    const struct timespec64 *tv)
2543 {
2544 	__be32 *p;
2545 
2546 	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
2547 	if (!p)
2548 		return nfserr_resource;
2549 	p = xdr_encode_hyper(p, tv->tv_sec);
2550 	*p = cpu_to_be32(tv->tv_nsec);
2551 	return nfs_ok;
2552 }
2553 
2554 static __be32 nfsd4_encode_specdata4(struct xdr_stream *xdr,
2555 				     unsigned int major, unsigned int minor)
2556 {
2557 	__be32 status;
2558 
2559 	status = nfsd4_encode_uint32_t(xdr, major);
2560 	if (status != nfs_ok)
2561 		return status;
2562 	return nfsd4_encode_uint32_t(xdr, minor);
2563 }
2564 
2565 static __be32
2566 nfsd4_encode_change_info4(struct xdr_stream *xdr, const struct nfsd4_change_info *c)
2567 {
2568 	__be32 status;
2569 
2570 	status = nfsd4_encode_bool(xdr, c->atomic);
2571 	if (status != nfs_ok)
2572 		return status;
2573 	status = nfsd4_encode_changeid4(xdr, c->before_change);
2574 	if (status != nfs_ok)
2575 		return status;
2576 	return nfsd4_encode_changeid4(xdr, c->after_change);
2577 }
2578 
2579 static __be32 nfsd4_encode_netaddr4(struct xdr_stream *xdr,
2580 				    const struct nfs42_netaddr *addr)
2581 {
2582 	__be32 status;
2583 
2584 	/* na_r_netid */
2585 	status = nfsd4_encode_opaque(xdr, addr->netid, addr->netid_len);
2586 	if (status != nfs_ok)
2587 		return status;
2588 	/* na_r_addr */
2589 	return nfsd4_encode_opaque(xdr, addr->addr, addr->addr_len);
2590 }
2591 
2592 /* Encode as an array of strings the string given with components
2593  * separated @sep, escaped with esc_enter and esc_exit.
2594  */
2595 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2596 					  char *components, char esc_enter,
2597 					  char esc_exit)
2598 {
2599 	__be32 *p;
2600 	__be32 pathlen;
2601 	int pathlen_offset;
2602 	int strlen, count=0;
2603 	char *str, *end, *next;
2604 
2605 	dprintk("nfsd4_encode_components(%s)\n", components);
2606 
2607 	pathlen_offset = xdr->buf->len;
2608 	p = xdr_reserve_space(xdr, 4);
2609 	if (!p)
2610 		return nfserr_resource;
2611 	p++; /* We will fill this in with @count later */
2612 
2613 	end = str = components;
2614 	while (*end) {
2615 		bool found_esc = false;
2616 
2617 		/* try to parse as esc_start, ..., esc_end, sep */
2618 		if (*str == esc_enter) {
2619 			for (; *end && (*end != esc_exit); end++)
2620 				/* find esc_exit or end of string */;
2621 			next = end + 1;
2622 			if (*end && (!*next || *next == sep)) {
2623 				str++;
2624 				found_esc = true;
2625 			}
2626 		}
2627 
2628 		if (!found_esc)
2629 			for (; *end && (*end != sep); end++)
2630 				/* find sep or end of string */;
2631 
2632 		strlen = end - str;
2633 		if (strlen) {
2634 			p = xdr_reserve_space(xdr, strlen + 4);
2635 			if (!p)
2636 				return nfserr_resource;
2637 			p = xdr_encode_opaque(p, str, strlen);
2638 			count++;
2639 		}
2640 		else
2641 			end++;
2642 		if (found_esc)
2643 			end = next;
2644 
2645 		str = end;
2646 	}
2647 	pathlen = htonl(count);
2648 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2649 	return 0;
2650 }
2651 
2652 /* Encode as an array of strings the string given with components
2653  * separated @sep.
2654  */
2655 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2656 				      char *components)
2657 {
2658 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2659 }
2660 
2661 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2662 					struct nfsd4_fs_location *location)
2663 {
2664 	__be32 status;
2665 
2666 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2667 						'[', ']');
2668 	if (status)
2669 		return status;
2670 	status = nfsd4_encode_components(xdr, '/', location->path);
2671 	if (status)
2672 		return status;
2673 	return nfs_ok;
2674 }
2675 
2676 static __be32 nfsd4_encode_pathname4(struct xdr_stream *xdr,
2677 				     const struct path *root,
2678 				     const struct path *path)
2679 {
2680 	struct path cur = *path;
2681 	__be32 *p;
2682 	struct dentry **components = NULL;
2683 	unsigned int ncomponents = 0;
2684 	__be32 err = nfserr_jukebox;
2685 
2686 	dprintk("nfsd4_encode_components(");
2687 
2688 	path_get(&cur);
2689 	/* First walk the path up to the nfsd root, and store the
2690 	 * dentries/path components in an array.
2691 	 */
2692 	for (;;) {
2693 		if (path_equal(&cur, root))
2694 			break;
2695 		if (cur.dentry == cur.mnt->mnt_root) {
2696 			if (follow_up(&cur))
2697 				continue;
2698 			goto out_free;
2699 		}
2700 		if ((ncomponents & 15) == 0) {
2701 			struct dentry **new;
2702 			new = krealloc(components,
2703 					sizeof(*new) * (ncomponents + 16),
2704 					GFP_KERNEL);
2705 			if (!new)
2706 				goto out_free;
2707 			components = new;
2708 		}
2709 		components[ncomponents++] = cur.dentry;
2710 		cur.dentry = dget_parent(cur.dentry);
2711 	}
2712 	err = nfserr_resource;
2713 	p = xdr_reserve_space(xdr, 4);
2714 	if (!p)
2715 		goto out_free;
2716 	*p++ = cpu_to_be32(ncomponents);
2717 
2718 	while (ncomponents) {
2719 		struct dentry *dentry = components[ncomponents - 1];
2720 		unsigned int len;
2721 
2722 		spin_lock(&dentry->d_lock);
2723 		len = dentry->d_name.len;
2724 		p = xdr_reserve_space(xdr, len + 4);
2725 		if (!p) {
2726 			spin_unlock(&dentry->d_lock);
2727 			goto out_free;
2728 		}
2729 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2730 		dprintk("/%pd", dentry);
2731 		spin_unlock(&dentry->d_lock);
2732 		dput(dentry);
2733 		ncomponents--;
2734 	}
2735 
2736 	err = 0;
2737 out_free:
2738 	dprintk(")\n");
2739 	while (ncomponents)
2740 		dput(components[--ncomponents]);
2741 	kfree(components);
2742 	path_put(&cur);
2743 	return err;
2744 }
2745 
2746 static __be32 nfsd4_encode_fs_locations4(struct xdr_stream *xdr,
2747 					 struct svc_rqst *rqstp,
2748 					 struct svc_export *exp)
2749 {
2750 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2751 	struct svc_export *exp_ps;
2752 	unsigned int i;
2753 	__be32 status;
2754 
2755 	/* fs_root */
2756 	exp_ps = rqst_find_fsidzero_export(rqstp);
2757 	if (IS_ERR(exp_ps))
2758 		return nfserrno(PTR_ERR(exp_ps));
2759 	status = nfsd4_encode_pathname4(xdr, &exp_ps->ex_path, &exp->ex_path);
2760 	exp_put(exp_ps);
2761 	if (status != nfs_ok)
2762 		return status;
2763 
2764 	/* locations<> */
2765 	if (xdr_stream_encode_u32(xdr, fslocs->locations_count) != XDR_UNIT)
2766 		return nfserr_resource;
2767 	for (i = 0; i < fslocs->locations_count; i++) {
2768 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2769 		if (status != nfs_ok)
2770 			return status;
2771 	}
2772 
2773 	return nfs_ok;
2774 }
2775 
2776 static __be32 nfsd4_encode_nfsace4(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2777 				   struct nfs4_ace *ace)
2778 {
2779 	__be32 status;
2780 
2781 	/* type */
2782 	status = nfsd4_encode_acetype4(xdr, ace->type);
2783 	if (status != nfs_ok)
2784 		return nfserr_resource;
2785 	/* flag */
2786 	status = nfsd4_encode_aceflag4(xdr, ace->flag);
2787 	if (status != nfs_ok)
2788 		return nfserr_resource;
2789 	/* access mask */
2790 	status = nfsd4_encode_acemask4(xdr, ace->access_mask & NFS4_ACE_MASK_ALL);
2791 	if (status != nfs_ok)
2792 		return nfserr_resource;
2793 	/* who */
2794 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2795 		return nfs4_acl_write_who(xdr, ace->whotype);
2796 	if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2797 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2798 	return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2799 }
2800 
2801 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2802 			      FATTR4_WORD0_RDATTR_ERROR)
2803 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2804 #define WORD2_ABSENT_FS_ATTRS 0
2805 
2806 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2807 static inline __be32
2808 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2809 			    void *context, int len)
2810 {
2811 	__be32 *p;
2812 
2813 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2814 	if (!p)
2815 		return nfserr_resource;
2816 
2817 	/*
2818 	 * For now we use a 0 here to indicate the null translation; in
2819 	 * the future we may place a call to translation code here.
2820 	 */
2821 	*p++ = cpu_to_be32(0); /* lfs */
2822 	*p++ = cpu_to_be32(0); /* pi */
2823 	p = xdr_encode_opaque(p, context, len);
2824 	return 0;
2825 }
2826 #else
2827 static inline __be32
2828 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2829 			    void *context, int len)
2830 { return 0; }
2831 #endif
2832 
2833 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2834 {
2835 	/* As per referral draft:  */
2836 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2837 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2838 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2839 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2840 			*rdattr_err = NFSERR_MOVED;
2841 		else
2842 			return nfserr_moved;
2843 	}
2844 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2845 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2846 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2847 	return 0;
2848 }
2849 
2850 
2851 static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
2852 {
2853 	struct path path = exp->ex_path;
2854 	struct kstat stat;
2855 	int err;
2856 
2857 	path_get(&path);
2858 	while (follow_up(&path)) {
2859 		if (path.dentry != path.mnt->mnt_root)
2860 			break;
2861 	}
2862 	err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
2863 	path_put(&path);
2864 	if (!err)
2865 		*pino = stat.ino;
2866 	return err;
2867 }
2868 
2869 static __be32
2870 nfsd4_encode_bitmap4(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2871 {
2872 	__be32 *p;
2873 
2874 	if (bmval2) {
2875 		p = xdr_reserve_space(xdr, XDR_UNIT * 4);
2876 		if (!p)
2877 			goto out_resource;
2878 		*p++ = cpu_to_be32(3);
2879 		*p++ = cpu_to_be32(bmval0);
2880 		*p++ = cpu_to_be32(bmval1);
2881 		*p++ = cpu_to_be32(bmval2);
2882 	} else if (bmval1) {
2883 		p = xdr_reserve_space(xdr, XDR_UNIT * 3);
2884 		if (!p)
2885 			goto out_resource;
2886 		*p++ = cpu_to_be32(2);
2887 		*p++ = cpu_to_be32(bmval0);
2888 		*p++ = cpu_to_be32(bmval1);
2889 	} else {
2890 		p = xdr_reserve_space(xdr, XDR_UNIT * 2);
2891 		if (!p)
2892 			goto out_resource;
2893 		*p++ = cpu_to_be32(1);
2894 		*p++ = cpu_to_be32(bmval0);
2895 	}
2896 
2897 	return nfs_ok;
2898 out_resource:
2899 	return nfserr_resource;
2900 }
2901 
2902 struct nfsd4_fattr_args {
2903 	struct svc_rqst		*rqstp;
2904 	struct svc_fh		*fhp;
2905 	struct svc_export	*exp;
2906 	struct dentry		*dentry;
2907 	struct kstat		stat;
2908 	struct kstatfs		statfs;
2909 	struct nfs4_acl		*acl;
2910 	u64			size;
2911 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2912 	void			*context;
2913 	int			contextlen;
2914 #endif
2915 	u32			rdattr_err;
2916 	bool			contextsupport;
2917 	bool			ignore_crossmnt;
2918 };
2919 
2920 typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr,
2921 				const struct nfsd4_fattr_args *args);
2922 
2923 static __be32 nfsd4_encode_fattr4__noop(struct xdr_stream *xdr,
2924 					const struct nfsd4_fattr_args *args)
2925 {
2926 	return nfs_ok;
2927 }
2928 
2929 static __be32 nfsd4_encode_fattr4__true(struct xdr_stream *xdr,
2930 					const struct nfsd4_fattr_args *args)
2931 {
2932 	return nfsd4_encode_bool(xdr, true);
2933 }
2934 
2935 static __be32 nfsd4_encode_fattr4__false(struct xdr_stream *xdr,
2936 					 const struct nfsd4_fattr_args *args)
2937 {
2938 	return nfsd4_encode_bool(xdr, false);
2939 }
2940 
2941 static __be32 nfsd4_encode_fattr4_supported_attrs(struct xdr_stream *xdr,
2942 						  const struct nfsd4_fattr_args *args)
2943 {
2944 	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
2945 	u32 minorversion = resp->cstate.minorversion;
2946 	u32 supp[3];
2947 
2948 	memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2949 	if (!IS_POSIXACL(d_inode(args->dentry)))
2950 		supp[0] &= ~FATTR4_WORD0_ACL;
2951 	if (!args->contextsupport)
2952 		supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2953 
2954 	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
2955 }
2956 
2957 static __be32 nfsd4_encode_fattr4_type(struct xdr_stream *xdr,
2958 				       const struct nfsd4_fattr_args *args)
2959 {
2960 	__be32 *p;
2961 
2962 	p = xdr_reserve_space(xdr, XDR_UNIT);
2963 	if (!p)
2964 		return nfserr_resource;
2965 
2966 	switch (args->stat.mode & S_IFMT) {
2967 	case S_IFIFO:
2968 		*p = cpu_to_be32(NF4FIFO);
2969 		break;
2970 	case S_IFCHR:
2971 		*p = cpu_to_be32(NF4CHR);
2972 		break;
2973 	case S_IFDIR:
2974 		*p = cpu_to_be32(NF4DIR);
2975 		break;
2976 	case S_IFBLK:
2977 		*p = cpu_to_be32(NF4BLK);
2978 		break;
2979 	case S_IFLNK:
2980 		*p = cpu_to_be32(NF4LNK);
2981 		break;
2982 	case S_IFREG:
2983 		*p = cpu_to_be32(NF4REG);
2984 		break;
2985 	case S_IFSOCK:
2986 		*p = cpu_to_be32(NF4SOCK);
2987 		break;
2988 	default:
2989 		return nfserr_serverfault;
2990 	}
2991 
2992 	return nfs_ok;
2993 }
2994 
2995 static __be32 nfsd4_encode_fattr4_fh_expire_type(struct xdr_stream *xdr,
2996 						 const struct nfsd4_fattr_args *args)
2997 {
2998 	u32 mask;
2999 
3000 	mask = NFS4_FH_PERSISTENT;
3001 	if (!(args->exp->ex_flags & NFSEXP_NOSUBTREECHECK))
3002 		mask |= NFS4_FH_VOL_RENAME;
3003 	return nfsd4_encode_uint32_t(xdr, mask);
3004 }
3005 
3006 static __be32 nfsd4_encode_fattr4_change(struct xdr_stream *xdr,
3007 					 const struct nfsd4_fattr_args *args)
3008 {
3009 	const struct svc_export *exp = args->exp;
3010 	u64 c;
3011 
3012 	if (unlikely(exp->ex_flags & NFSEXP_V4ROOT)) {
3013 		u32 flush_time = convert_to_wallclock(exp->cd->flush_time);
3014 
3015 		if (xdr_stream_encode_u32(xdr, flush_time) != XDR_UNIT)
3016 			return nfserr_resource;
3017 		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
3018 			return nfserr_resource;
3019 		return nfs_ok;
3020 	}
3021 
3022 	c = nfsd4_change_attribute(&args->stat, d_inode(args->dentry));
3023 	return nfsd4_encode_changeid4(xdr, c);
3024 }
3025 
3026 static __be32 nfsd4_encode_fattr4_size(struct xdr_stream *xdr,
3027 				       const struct nfsd4_fattr_args *args)
3028 {
3029 	return nfsd4_encode_uint64_t(xdr, args->size);
3030 }
3031 
3032 static __be32 nfsd4_encode_fattr4_fsid(struct xdr_stream *xdr,
3033 				       const struct nfsd4_fattr_args *args)
3034 {
3035 	__be32 *p;
3036 
3037 	p = xdr_reserve_space(xdr, XDR_UNIT * 2 + XDR_UNIT * 2);
3038 	if (!p)
3039 		return nfserr_resource;
3040 
3041 	if (unlikely(args->exp->ex_fslocs.migrated)) {
3042 		p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
3043 		xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
3044 		return nfs_ok;
3045 	}
3046 	switch (fsid_source(args->fhp)) {
3047 	case FSIDSOURCE_FSID:
3048 		p = xdr_encode_hyper(p, (u64)args->exp->ex_fsid);
3049 		xdr_encode_hyper(p, (u64)0);
3050 		break;
3051 	case FSIDSOURCE_DEV:
3052 		*p++ = xdr_zero;
3053 		*p++ = cpu_to_be32(MAJOR(args->stat.dev));
3054 		*p++ = xdr_zero;
3055 		*p   = cpu_to_be32(MINOR(args->stat.dev));
3056 		break;
3057 	case FSIDSOURCE_UUID:
3058 		xdr_encode_opaque_fixed(p, args->exp->ex_uuid, EX_UUID_LEN);
3059 		break;
3060 	}
3061 
3062 	return nfs_ok;
3063 }
3064 
3065 static __be32 nfsd4_encode_fattr4_lease_time(struct xdr_stream *xdr,
3066 					     const struct nfsd4_fattr_args *args)
3067 {
3068 	struct nfsd_net *nn = net_generic(SVC_NET(args->rqstp), nfsd_net_id);
3069 
3070 	return nfsd4_encode_nfs_lease4(xdr, nn->nfsd4_lease);
3071 }
3072 
3073 static __be32 nfsd4_encode_fattr4_rdattr_error(struct xdr_stream *xdr,
3074 					       const struct nfsd4_fattr_args *args)
3075 {
3076 	return nfsd4_encode_uint32_t(xdr, args->rdattr_err);
3077 }
3078 
3079 static __be32 nfsd4_encode_fattr4_aclsupport(struct xdr_stream *xdr,
3080 					     const struct nfsd4_fattr_args *args)
3081 {
3082 	u32 mask;
3083 
3084 	mask = 0;
3085 	if (IS_POSIXACL(d_inode(args->dentry)))
3086 		mask = ACL4_SUPPORT_ALLOW_ACL | ACL4_SUPPORT_DENY_ACL;
3087 	return nfsd4_encode_uint32_t(xdr, mask);
3088 }
3089 
3090 static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,
3091 				      const struct nfsd4_fattr_args *args)
3092 {
3093 	struct nfs4_acl *acl = args->acl;
3094 	struct nfs4_ace *ace;
3095 	__be32 status;
3096 
3097 	/* nfsace4<> */
3098 	if (!acl) {
3099 		if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
3100 			return nfserr_resource;
3101 	} else {
3102 		if (xdr_stream_encode_u32(xdr, acl->naces) != XDR_UNIT)
3103 			return nfserr_resource;
3104 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
3105 			status = nfsd4_encode_nfsace4(xdr, args->rqstp, ace);
3106 			if (status != nfs_ok)
3107 				return status;
3108 		}
3109 	}
3110 	return nfs_ok;
3111 }
3112 
3113 static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,
3114 					     const struct nfsd4_fattr_args *args)
3115 {
3116 	return nfsd4_encode_nfs_fh4(xdr, &args->fhp->fh_handle);
3117 }
3118 
3119 static __be32 nfsd4_encode_fattr4_fileid(struct xdr_stream *xdr,
3120 					 const struct nfsd4_fattr_args *args)
3121 {
3122 	return nfsd4_encode_uint64_t(xdr, args->stat.ino);
3123 }
3124 
3125 static __be32 nfsd4_encode_fattr4_files_avail(struct xdr_stream *xdr,
3126 					      const struct nfsd4_fattr_args *args)
3127 {
3128 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
3129 }
3130 
3131 static __be32 nfsd4_encode_fattr4_files_free(struct xdr_stream *xdr,
3132 					     const struct nfsd4_fattr_args *args)
3133 {
3134 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_ffree);
3135 }
3136 
3137 static __be32 nfsd4_encode_fattr4_files_total(struct xdr_stream *xdr,
3138 					      const struct nfsd4_fattr_args *args)
3139 {
3140 	return nfsd4_encode_uint64_t(xdr, args->statfs.f_files);
3141 }
3142 
3143 static __be32 nfsd4_encode_fattr4_fs_locations(struct xdr_stream *xdr,
3144 					       const struct nfsd4_fattr_args *args)
3145 {
3146 	return nfsd4_encode_fs_locations4(xdr, args->rqstp, args->exp);
3147 }
3148 
3149 static __be32 nfsd4_encode_fattr4_maxfilesize(struct xdr_stream *xdr,
3150 					      const struct nfsd4_fattr_args *args)
3151 {
3152 	struct super_block *sb = args->exp->ex_path.mnt->mnt_sb;
3153 
3154 	return nfsd4_encode_uint64_t(xdr, sb->s_maxbytes);
3155 }
3156 
3157 static __be32 nfsd4_encode_fattr4_maxlink(struct xdr_stream *xdr,
3158 					  const struct nfsd4_fattr_args *args)
3159 {
3160 	return nfsd4_encode_uint32_t(xdr, 255);
3161 }
3162 
3163 static __be32 nfsd4_encode_fattr4_maxname(struct xdr_stream *xdr,
3164 					  const struct nfsd4_fattr_args *args)
3165 {
3166 	return nfsd4_encode_uint32_t(xdr, args->statfs.f_namelen);
3167 }
3168 
3169 static __be32 nfsd4_encode_fattr4_maxread(struct xdr_stream *xdr,
3170 					  const struct nfsd4_fattr_args *args)
3171 {
3172 	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
3173 }
3174 
3175 static __be32 nfsd4_encode_fattr4_maxwrite(struct xdr_stream *xdr,
3176 					   const struct nfsd4_fattr_args *args)
3177 {
3178 	return nfsd4_encode_uint64_t(xdr, svc_max_payload(args->rqstp));
3179 }
3180 
3181 static __be32 nfsd4_encode_fattr4_mode(struct xdr_stream *xdr,
3182 				       const struct nfsd4_fattr_args *args)
3183 {
3184 	return nfsd4_encode_mode4(xdr, args->stat.mode & S_IALLUGO);
3185 }
3186 
3187 static __be32 nfsd4_encode_fattr4_numlinks(struct xdr_stream *xdr,
3188 					   const struct nfsd4_fattr_args *args)
3189 {
3190 	return nfsd4_encode_uint32_t(xdr, args->stat.nlink);
3191 }
3192 
3193 static __be32 nfsd4_encode_fattr4_owner(struct xdr_stream *xdr,
3194 					const struct nfsd4_fattr_args *args)
3195 {
3196 	return nfsd4_encode_user(xdr, args->rqstp, args->stat.uid);
3197 }
3198 
3199 static __be32 nfsd4_encode_fattr4_owner_group(struct xdr_stream *xdr,
3200 					      const struct nfsd4_fattr_args *args)
3201 {
3202 	return nfsd4_encode_group(xdr, args->rqstp, args->stat.gid);
3203 }
3204 
3205 static __be32 nfsd4_encode_fattr4_rawdev(struct xdr_stream *xdr,
3206 					 const struct nfsd4_fattr_args *args)
3207 {
3208 	return nfsd4_encode_specdata4(xdr, MAJOR(args->stat.rdev),
3209 				      MINOR(args->stat.rdev));
3210 }
3211 
3212 static __be32 nfsd4_encode_fattr4_space_avail(struct xdr_stream *xdr,
3213 					      const struct nfsd4_fattr_args *args)
3214 {
3215 	u64 avail = (u64)args->statfs.f_bavail * (u64)args->statfs.f_bsize;
3216 
3217 	return nfsd4_encode_uint64_t(xdr, avail);
3218 }
3219 
3220 static __be32 nfsd4_encode_fattr4_space_free(struct xdr_stream *xdr,
3221 					     const struct nfsd4_fattr_args *args)
3222 {
3223 	u64 free = (u64)args->statfs.f_bfree * (u64)args->statfs.f_bsize;
3224 
3225 	return nfsd4_encode_uint64_t(xdr, free);
3226 }
3227 
3228 static __be32 nfsd4_encode_fattr4_space_total(struct xdr_stream *xdr,
3229 					      const struct nfsd4_fattr_args *args)
3230 {
3231 	u64 total = (u64)args->statfs.f_blocks * (u64)args->statfs.f_bsize;
3232 
3233 	return nfsd4_encode_uint64_t(xdr, total);
3234 }
3235 
3236 static __be32 nfsd4_encode_fattr4_space_used(struct xdr_stream *xdr,
3237 					     const struct nfsd4_fattr_args *args)
3238 {
3239 	return nfsd4_encode_uint64_t(xdr, (u64)args->stat.blocks << 9);
3240 }
3241 
3242 static __be32 nfsd4_encode_fattr4_time_access(struct xdr_stream *xdr,
3243 					      const struct nfsd4_fattr_args *args)
3244 {
3245 	return nfsd4_encode_nfstime4(xdr, &args->stat.atime);
3246 }
3247 
3248 static __be32 nfsd4_encode_fattr4_time_create(struct xdr_stream *xdr,
3249 					      const struct nfsd4_fattr_args *args)
3250 {
3251 	return nfsd4_encode_nfstime4(xdr, &args->stat.btime);
3252 }
3253 
3254 /*
3255  * ctime (in NFSv4, time_metadata) is not writeable, and the client
3256  * doesn't really care what resolution could theoretically be stored by
3257  * the filesystem.
3258  *
3259  * The client cares how close together changes can be while still
3260  * guaranteeing ctime changes.  For most filesystems (which have
3261  * timestamps with nanosecond fields) that is limited by the resolution
3262  * of the time returned from current_time() (which I'm assuming to be
3263  * 1/HZ).
3264  */
3265 static __be32 nfsd4_encode_fattr4_time_delta(struct xdr_stream *xdr,
3266 					     const struct nfsd4_fattr_args *args)
3267 {
3268 	const struct inode *inode = d_inode(args->dentry);
3269 	u32 ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
3270 	struct timespec64 ts = ns_to_timespec64(ns);
3271 
3272 	return nfsd4_encode_nfstime4(xdr, &ts);
3273 }
3274 
3275 static __be32 nfsd4_encode_fattr4_time_metadata(struct xdr_stream *xdr,
3276 						const struct nfsd4_fattr_args *args)
3277 {
3278 	return nfsd4_encode_nfstime4(xdr, &args->stat.ctime);
3279 }
3280 
3281 static __be32 nfsd4_encode_fattr4_time_modify(struct xdr_stream *xdr,
3282 					      const struct nfsd4_fattr_args *args)
3283 {
3284 	return nfsd4_encode_nfstime4(xdr, &args->stat.mtime);
3285 }
3286 
3287 static __be32 nfsd4_encode_fattr4_mounted_on_fileid(struct xdr_stream *xdr,
3288 						    const struct nfsd4_fattr_args *args)
3289 {
3290 	u64 ino;
3291 	int err;
3292 
3293 	if (!args->ignore_crossmnt &&
3294 	    args->dentry == args->exp->ex_path.mnt->mnt_root) {
3295 		err = nfsd4_get_mounted_on_ino(args->exp, &ino);
3296 		if (err)
3297 			return nfserrno(err);
3298 	} else
3299 		ino = args->stat.ino;
3300 
3301 	return nfsd4_encode_uint64_t(xdr, ino);
3302 }
3303 
3304 #ifdef CONFIG_NFSD_PNFS
3305 
3306 static __be32 nfsd4_encode_fattr4_fs_layout_types(struct xdr_stream *xdr,
3307 						  const struct nfsd4_fattr_args *args)
3308 {
3309 	unsigned long mask = args->exp->ex_layout_types;
3310 	int i;
3311 
3312 	/* Hamming weight of @mask is the number of layout types to return */
3313 	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
3314 		return nfserr_resource;
3315 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
3316 		if (mask & BIT(i)) {
3317 			/* layouttype4 */
3318 			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
3319 				return nfserr_resource;
3320 		}
3321 	return nfs_ok;
3322 }
3323 
3324 static __be32 nfsd4_encode_fattr4_layout_types(struct xdr_stream *xdr,
3325 					       const struct nfsd4_fattr_args *args)
3326 {
3327 	unsigned long mask = args->exp->ex_layout_types;
3328 	int i;
3329 
3330 	/* Hamming weight of @mask is the number of layout types to return */
3331 	if (xdr_stream_encode_u32(xdr, hweight_long(mask)) != XDR_UNIT)
3332 		return nfserr_resource;
3333 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
3334 		if (mask & BIT(i)) {
3335 			/* layouttype4 */
3336 			if (xdr_stream_encode_u32(xdr, i) != XDR_UNIT)
3337 				return nfserr_resource;
3338 		}
3339 	return nfs_ok;
3340 }
3341 
3342 static __be32 nfsd4_encode_fattr4_layout_blksize(struct xdr_stream *xdr,
3343 						 const struct nfsd4_fattr_args *args)
3344 {
3345 	return nfsd4_encode_uint32_t(xdr, args->stat.blksize);
3346 }
3347 
3348 #endif
3349 
3350 static __be32 nfsd4_encode_fattr4_suppattr_exclcreat(struct xdr_stream *xdr,
3351 						     const struct nfsd4_fattr_args *args)
3352 {
3353 	struct nfsd4_compoundres *resp = args->rqstp->rq_resp;
3354 	u32 supp[3];
3355 
3356 	memcpy(supp, nfsd_suppattrs[resp->cstate.minorversion], sizeof(supp));
3357 	supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
3358 	supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
3359 	supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
3360 
3361 	return nfsd4_encode_bitmap4(xdr, supp[0], supp[1], supp[2]);
3362 }
3363 
3364 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3365 static __be32 nfsd4_encode_fattr4_sec_label(struct xdr_stream *xdr,
3366 					    const struct nfsd4_fattr_args *args)
3367 {
3368 	return nfsd4_encode_security_label(xdr, args->rqstp,
3369 					   args->context, args->contextlen);
3370 }
3371 #endif
3372 
3373 static __be32 nfsd4_encode_fattr4_xattr_support(struct xdr_stream *xdr,
3374 						const struct nfsd4_fattr_args *args)
3375 {
3376 	int err = xattr_supports_user_prefix(d_inode(args->dentry));
3377 
3378 	return nfsd4_encode_bool(xdr, err == 0);
3379 }
3380 
3381 static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {
3382 	[FATTR4_SUPPORTED_ATTRS]	= nfsd4_encode_fattr4_supported_attrs,
3383 	[FATTR4_TYPE]			= nfsd4_encode_fattr4_type,
3384 	[FATTR4_FH_EXPIRE_TYPE]		= nfsd4_encode_fattr4_fh_expire_type,
3385 	[FATTR4_CHANGE]			= nfsd4_encode_fattr4_change,
3386 	[FATTR4_SIZE]			= nfsd4_encode_fattr4_size,
3387 	[FATTR4_LINK_SUPPORT]		= nfsd4_encode_fattr4__true,
3388 	[FATTR4_SYMLINK_SUPPORT]	= nfsd4_encode_fattr4__true,
3389 	[FATTR4_NAMED_ATTR]		= nfsd4_encode_fattr4__false,
3390 	[FATTR4_FSID]			= nfsd4_encode_fattr4_fsid,
3391 	[FATTR4_UNIQUE_HANDLES]		= nfsd4_encode_fattr4__true,
3392 	[FATTR4_LEASE_TIME]		= nfsd4_encode_fattr4_lease_time,
3393 	[FATTR4_RDATTR_ERROR]		= nfsd4_encode_fattr4_rdattr_error,
3394 	[FATTR4_ACL]			= nfsd4_encode_fattr4_acl,
3395 	[FATTR4_ACLSUPPORT]		= nfsd4_encode_fattr4_aclsupport,
3396 	[FATTR4_ARCHIVE]		= nfsd4_encode_fattr4__noop,
3397 	[FATTR4_CANSETTIME]		= nfsd4_encode_fattr4__true,
3398 	[FATTR4_CASE_INSENSITIVE]	= nfsd4_encode_fattr4__false,
3399 	[FATTR4_CASE_PRESERVING]	= nfsd4_encode_fattr4__true,
3400 	[FATTR4_CHOWN_RESTRICTED]	= nfsd4_encode_fattr4__true,
3401 	[FATTR4_FILEHANDLE]		= nfsd4_encode_fattr4_filehandle,
3402 	[FATTR4_FILEID]			= nfsd4_encode_fattr4_fileid,
3403 	[FATTR4_FILES_AVAIL]		= nfsd4_encode_fattr4_files_avail,
3404 	[FATTR4_FILES_FREE]		= nfsd4_encode_fattr4_files_free,
3405 	[FATTR4_FILES_TOTAL]		= nfsd4_encode_fattr4_files_total,
3406 	[FATTR4_FS_LOCATIONS]		= nfsd4_encode_fattr4_fs_locations,
3407 	[FATTR4_HIDDEN]			= nfsd4_encode_fattr4__noop,
3408 	[FATTR4_HOMOGENEOUS]		= nfsd4_encode_fattr4__true,
3409 	[FATTR4_MAXFILESIZE]		= nfsd4_encode_fattr4_maxfilesize,
3410 	[FATTR4_MAXLINK]		= nfsd4_encode_fattr4_maxlink,
3411 	[FATTR4_MAXNAME]		= nfsd4_encode_fattr4_maxname,
3412 	[FATTR4_MAXREAD]		= nfsd4_encode_fattr4_maxread,
3413 	[FATTR4_MAXWRITE]		= nfsd4_encode_fattr4_maxwrite,
3414 	[FATTR4_MIMETYPE]		= nfsd4_encode_fattr4__noop,
3415 	[FATTR4_MODE]			= nfsd4_encode_fattr4_mode,
3416 	[FATTR4_NO_TRUNC]		= nfsd4_encode_fattr4__true,
3417 	[FATTR4_NUMLINKS]		= nfsd4_encode_fattr4_numlinks,
3418 	[FATTR4_OWNER]			= nfsd4_encode_fattr4_owner,
3419 	[FATTR4_OWNER_GROUP]		= nfsd4_encode_fattr4_owner_group,
3420 	[FATTR4_QUOTA_AVAIL_HARD]	= nfsd4_encode_fattr4__noop,
3421 	[FATTR4_QUOTA_AVAIL_SOFT]	= nfsd4_encode_fattr4__noop,
3422 	[FATTR4_QUOTA_USED]		= nfsd4_encode_fattr4__noop,
3423 	[FATTR4_RAWDEV]			= nfsd4_encode_fattr4_rawdev,
3424 	[FATTR4_SPACE_AVAIL]		= nfsd4_encode_fattr4_space_avail,
3425 	[FATTR4_SPACE_FREE]		= nfsd4_encode_fattr4_space_free,
3426 	[FATTR4_SPACE_TOTAL]		= nfsd4_encode_fattr4_space_total,
3427 	[FATTR4_SPACE_USED]		= nfsd4_encode_fattr4_space_used,
3428 	[FATTR4_SYSTEM]			= nfsd4_encode_fattr4__noop,
3429 	[FATTR4_TIME_ACCESS]		= nfsd4_encode_fattr4_time_access,
3430 	[FATTR4_TIME_ACCESS_SET]	= nfsd4_encode_fattr4__noop,
3431 	[FATTR4_TIME_BACKUP]		= nfsd4_encode_fattr4__noop,
3432 	[FATTR4_TIME_CREATE]		= nfsd4_encode_fattr4_time_create,
3433 	[FATTR4_TIME_DELTA]		= nfsd4_encode_fattr4_time_delta,
3434 	[FATTR4_TIME_METADATA]		= nfsd4_encode_fattr4_time_metadata,
3435 	[FATTR4_TIME_MODIFY]		= nfsd4_encode_fattr4_time_modify,
3436 	[FATTR4_TIME_MODIFY_SET]	= nfsd4_encode_fattr4__noop,
3437 	[FATTR4_MOUNTED_ON_FILEID]	= nfsd4_encode_fattr4_mounted_on_fileid,
3438 	[FATTR4_DIR_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
3439 	[FATTR4_DIRENT_NOTIF_DELAY]	= nfsd4_encode_fattr4__noop,
3440 	[FATTR4_DACL]			= nfsd4_encode_fattr4__noop,
3441 	[FATTR4_SACL]			= nfsd4_encode_fattr4__noop,
3442 	[FATTR4_CHANGE_POLICY]		= nfsd4_encode_fattr4__noop,
3443 	[FATTR4_FS_STATUS]		= nfsd4_encode_fattr4__noop,
3444 
3445 #ifdef CONFIG_NFSD_PNFS
3446 	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4_fs_layout_types,
3447 	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
3448 	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4_layout_types,
3449 	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4_layout_blksize,
3450 	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
3451 #else
3452 	[FATTR4_FS_LAYOUT_TYPES]	= nfsd4_encode_fattr4__noop,
3453 	[FATTR4_LAYOUT_HINT]		= nfsd4_encode_fattr4__noop,
3454 	[FATTR4_LAYOUT_TYPES]		= nfsd4_encode_fattr4__noop,
3455 	[FATTR4_LAYOUT_BLKSIZE]		= nfsd4_encode_fattr4__noop,
3456 	[FATTR4_LAYOUT_ALIGNMENT]	= nfsd4_encode_fattr4__noop,
3457 #endif
3458 
3459 	[FATTR4_FS_LOCATIONS_INFO]	= nfsd4_encode_fattr4__noop,
3460 	[FATTR4_MDSTHRESHOLD]		= nfsd4_encode_fattr4__noop,
3461 	[FATTR4_RETENTION_GET]		= nfsd4_encode_fattr4__noop,
3462 	[FATTR4_RETENTION_SET]		= nfsd4_encode_fattr4__noop,
3463 	[FATTR4_RETENTEVT_GET]		= nfsd4_encode_fattr4__noop,
3464 	[FATTR4_RETENTEVT_SET]		= nfsd4_encode_fattr4__noop,
3465 	[FATTR4_RETENTION_HOLD]		= nfsd4_encode_fattr4__noop,
3466 	[FATTR4_MODE_SET_MASKED]	= nfsd4_encode_fattr4__noop,
3467 	[FATTR4_SUPPATTR_EXCLCREAT]	= nfsd4_encode_fattr4_suppattr_exclcreat,
3468 	[FATTR4_FS_CHARSET_CAP]		= nfsd4_encode_fattr4__noop,
3469 	[FATTR4_CLONE_BLKSIZE]		= nfsd4_encode_fattr4__noop,
3470 	[FATTR4_SPACE_FREED]		= nfsd4_encode_fattr4__noop,
3471 	[FATTR4_CHANGE_ATTR_TYPE]	= nfsd4_encode_fattr4__noop,
3472 
3473 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3474 	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4_sec_label,
3475 #else
3476 	[FATTR4_SEC_LABEL]		= nfsd4_encode_fattr4__noop,
3477 #endif
3478 
3479 	[FATTR4_MODE_UMASK]		= nfsd4_encode_fattr4__noop,
3480 	[FATTR4_XATTR_SUPPORT]		= nfsd4_encode_fattr4_xattr_support,
3481 };
3482 
3483 /*
3484  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
3485  * ourselves.
3486  */
3487 static __be32
3488 nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
3489 		    struct svc_fh *fhp, struct svc_export *exp,
3490 		    struct dentry *dentry, const u32 *bmval,
3491 		    int ignore_crossmnt)
3492 {
3493 	struct nfsd4_fattr_args args;
3494 	struct svc_fh *tempfh = NULL;
3495 	int starting_len = xdr->buf->len;
3496 	__be32 *attrlen_p, status;
3497 	int attrlen_offset;
3498 	int err;
3499 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
3500 	u32 minorversion = resp->cstate.minorversion;
3501 	struct path path = {
3502 		.mnt	= exp->ex_path.mnt,
3503 		.dentry	= dentry,
3504 	};
3505 	union {
3506 		u32		attrmask[3];
3507 		unsigned long	mask[2];
3508 	} u;
3509 	unsigned long bit;
3510 	bool file_modified = false;
3511 	u64 size = 0;
3512 
3513 	WARN_ON_ONCE(bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1);
3514 	WARN_ON_ONCE(!nfsd_attrs_supported(minorversion, bmval));
3515 
3516 	args.rqstp = rqstp;
3517 	args.exp = exp;
3518 	args.dentry = dentry;
3519 	args.ignore_crossmnt = (ignore_crossmnt != 0);
3520 
3521 	/*
3522 	 * Make a local copy of the attribute bitmap that can be modified.
3523 	 */
3524 	memset(&u, 0, sizeof(u));
3525 	u.attrmask[0] = bmval[0];
3526 	u.attrmask[1] = bmval[1];
3527 	u.attrmask[2] = bmval[2];
3528 
3529 	args.rdattr_err = 0;
3530 	if (exp->ex_fslocs.migrated) {
3531 		status = fattr_handle_absent_fs(&u.attrmask[0], &u.attrmask[1],
3532 						&u.attrmask[2], &args.rdattr_err);
3533 		if (status)
3534 			goto out;
3535 	}
3536 	args.size = 0;
3537 	if (u.attrmask[0] & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {
3538 		status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry),
3539 					&file_modified, &size);
3540 		if (status)
3541 			goto out;
3542 	}
3543 
3544 	err = vfs_getattr(&path, &args.stat,
3545 			  STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
3546 			  AT_STATX_SYNC_AS_STAT);
3547 	if (err)
3548 		goto out_nfserr;
3549 	if (file_modified)
3550 		args.size = size;
3551 	else
3552 		args.size = args.stat.size;
3553 
3554 	if (!(args.stat.result_mask & STATX_BTIME))
3555 		/* underlying FS does not offer btime so we can't share it */
3556 		u.attrmask[1] &= ~FATTR4_WORD1_TIME_CREATE;
3557 	if ((u.attrmask[0] & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
3558 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
3559 	    (u.attrmask[1] & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
3560 		       FATTR4_WORD1_SPACE_TOTAL))) {
3561 		err = vfs_statfs(&path, &args.statfs);
3562 		if (err)
3563 			goto out_nfserr;
3564 	}
3565 	if ((u.attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) &&
3566 	    !fhp) {
3567 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
3568 		status = nfserr_jukebox;
3569 		if (!tempfh)
3570 			goto out;
3571 		fh_init(tempfh, NFS4_FHSIZE);
3572 		status = fh_compose(tempfh, exp, dentry, NULL);
3573 		if (status)
3574 			goto out;
3575 		args.fhp = tempfh;
3576 	} else
3577 		args.fhp = fhp;
3578 
3579 	args.acl = NULL;
3580 	if (u.attrmask[0] & FATTR4_WORD0_ACL) {
3581 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);
3582 		if (err == -EOPNOTSUPP)
3583 			u.attrmask[0] &= ~FATTR4_WORD0_ACL;
3584 		else if (err == -EINVAL) {
3585 			status = nfserr_attrnotsupp;
3586 			goto out;
3587 		} else if (err != 0)
3588 			goto out_nfserr;
3589 	}
3590 
3591 	args.contextsupport = false;
3592 
3593 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3594 	args.context = NULL;
3595 	if ((u.attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) ||
3596 	     u.attrmask[0] & FATTR4_WORD0_SUPPORTED_ATTRS) {
3597 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
3598 			err = security_inode_getsecctx(d_inode(dentry),
3599 						&args.context, &args.contextlen);
3600 		else
3601 			err = -EOPNOTSUPP;
3602 		args.contextsupport = (err == 0);
3603 		if (u.attrmask[2] & FATTR4_WORD2_SECURITY_LABEL) {
3604 			if (err == -EOPNOTSUPP)
3605 				u.attrmask[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
3606 			else if (err)
3607 				goto out_nfserr;
3608 		}
3609 	}
3610 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3611 
3612 	/* attrmask */
3613 	status = nfsd4_encode_bitmap4(xdr, u.attrmask[0],
3614 				      u.attrmask[1], u.attrmask[2]);
3615 	if (status)
3616 		goto out;
3617 
3618 	/* attr_vals */
3619 	attrlen_offset = xdr->buf->len;
3620 	attrlen_p = xdr_reserve_space(xdr, XDR_UNIT);
3621 	if (!attrlen_p)
3622 		goto out_resource;
3623 	for_each_set_bit(bit, (const unsigned long *)&u.mask,
3624 			 ARRAY_SIZE(nfsd4_enc_fattr4_encode_ops)) {
3625 		status = nfsd4_enc_fattr4_encode_ops[bit](xdr, &args);
3626 		if (status != nfs_ok)
3627 			goto out;
3628 	}
3629 	*attrlen_p = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
3630 	status = nfs_ok;
3631 
3632 out:
3633 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3634 	if (args.context)
3635 		security_release_secctx(args.context, args.contextlen);
3636 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3637 	kfree(args.acl);
3638 	if (tempfh) {
3639 		fh_put(tempfh);
3640 		kfree(tempfh);
3641 	}
3642 	if (status)
3643 		xdr_truncate_encode(xdr, starting_len);
3644 	return status;
3645 out_nfserr:
3646 	status = nfserrno(err);
3647 	goto out;
3648 out_resource:
3649 	status = nfserr_resource;
3650 	goto out;
3651 }
3652 
3653 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3654 				struct xdr_buf *buf, __be32 *p, int bytes)
3655 {
3656 	xdr->scratch.iov_len = 0;
3657 	memset(buf, 0, sizeof(struct xdr_buf));
3658 	buf->head[0].iov_base = p;
3659 	buf->head[0].iov_len = 0;
3660 	buf->len = 0;
3661 	xdr->buf = buf;
3662 	xdr->iov = buf->head;
3663 	xdr->p = p;
3664 	xdr->end = (void *)p + bytes;
3665 	buf->buflen = bytes;
3666 }
3667 
3668 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3669 			struct svc_fh *fhp, struct svc_export *exp,
3670 			struct dentry *dentry, u32 *bmval,
3671 			struct svc_rqst *rqstp, int ignore_crossmnt)
3672 {
3673 	struct xdr_buf dummy;
3674 	struct xdr_stream xdr;
3675 	__be32 ret;
3676 
3677 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3678 	ret = nfsd4_encode_fattr4(rqstp, &xdr, fhp, exp, dentry, bmval,
3679 				  ignore_crossmnt);
3680 	*p = xdr.p;
3681 	return ret;
3682 }
3683 
3684 /*
3685  * The buffer space for this field was reserved during a previous
3686  * call to nfsd4_encode_entry4().
3687  */
3688 static void nfsd4_encode_entry4_nfs_cookie4(const struct nfsd4_readdir *readdir,
3689 					    u64 offset)
3690 {
3691 	__be64 cookie = cpu_to_be64(offset);
3692 	struct xdr_stream *xdr = readdir->xdr;
3693 
3694 	if (!readdir->cookie_offset)
3695 		return;
3696 	write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset, &cookie,
3697 			       sizeof(cookie));
3698 }
3699 
3700 static inline int attributes_need_mount(u32 *bmval)
3701 {
3702 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3703 		return 1;
3704 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3705 		return 1;
3706 	return 0;
3707 }
3708 
3709 static __be32
3710 nfsd4_encode_entry4_fattr(struct nfsd4_readdir *cd, const char *name,
3711 			  int namlen)
3712 {
3713 	struct svc_export *exp = cd->rd_fhp->fh_export;
3714 	struct dentry *dentry;
3715 	__be32 nfserr;
3716 	int ignore_crossmnt = 0;
3717 
3718 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3719 	if (IS_ERR(dentry))
3720 		return nfserrno(PTR_ERR(dentry));
3721 
3722 	exp_get(exp);
3723 	/*
3724 	 * In the case of a mountpoint, the client may be asking for
3725 	 * attributes that are only properties of the underlying filesystem
3726 	 * as opposed to the cross-mounted file system. In such a case,
3727 	 * we will not follow the cross mount and will fill the attribtutes
3728 	 * directly from the mountpoint dentry.
3729 	 */
3730 	if (nfsd_mountpoint(dentry, exp)) {
3731 		int err;
3732 
3733 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3734 				&& !attributes_need_mount(cd->rd_bmval)) {
3735 			ignore_crossmnt = 1;
3736 			goto out_encode;
3737 		}
3738 		/*
3739 		 * Why the heck aren't we just using nfsd_lookup??
3740 		 * Different "."/".." handling?  Something else?
3741 		 * At least, add a comment here to explain....
3742 		 */
3743 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3744 		if (err) {
3745 			nfserr = nfserrno(err);
3746 			goto out_put;
3747 		}
3748 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3749 		if (nfserr)
3750 			goto out_put;
3751 
3752 	}
3753 out_encode:
3754 	nfserr = nfsd4_encode_fattr4(cd->rd_rqstp, cd->xdr, NULL, exp, dentry,
3755 				     cd->rd_bmval, ignore_crossmnt);
3756 out_put:
3757 	dput(dentry);
3758 	exp_put(exp);
3759 	return nfserr;
3760 }
3761 
3762 static __be32
3763 nfsd4_encode_entry4_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3764 {
3765 	__be32 status;
3766 
3767 	/* attrmask */
3768 	status = nfsd4_encode_bitmap4(xdr, FATTR4_WORD0_RDATTR_ERROR, 0, 0);
3769 	if (status != nfs_ok)
3770 		return status;
3771 	/* attr_vals */
3772 	if (xdr_stream_encode_u32(xdr, XDR_UNIT) != XDR_UNIT)
3773 		return nfserr_resource;
3774 	/* rdattr_error */
3775 	if (xdr_stream_encode_be32(xdr, nfserr) != XDR_UNIT)
3776 		return nfserr_resource;
3777 	return nfs_ok;
3778 }
3779 
3780 static int
3781 nfsd4_encode_entry4(void *ccdv, const char *name, int namlen,
3782 		    loff_t offset, u64 ino, unsigned int d_type)
3783 {
3784 	struct readdir_cd *ccd = ccdv;
3785 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3786 	struct xdr_stream *xdr = cd->xdr;
3787 	int start_offset = xdr->buf->len;
3788 	int cookie_offset;
3789 	u32 name_and_cookie;
3790 	int entry_bytes;
3791 	__be32 nfserr = nfserr_toosmall;
3792 
3793 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3794 	if (name && isdotent(name, namlen)) {
3795 		cd->common.err = nfs_ok;
3796 		return 0;
3797 	}
3798 
3799 	/* Encode the previous entry's cookie value */
3800 	nfsd4_encode_entry4_nfs_cookie4(cd, offset);
3801 
3802 	if (xdr_stream_encode_item_present(xdr) != XDR_UNIT)
3803 		goto fail;
3804 
3805 	/* Reserve send buffer space for this entry's cookie value. */
3806 	cookie_offset = xdr->buf->len;
3807 	if (nfsd4_encode_nfs_cookie4(xdr, OFFSET_MAX) != nfs_ok)
3808 		goto fail;
3809 	if (nfsd4_encode_component4(xdr, name, namlen) != nfs_ok)
3810 		goto fail;
3811 	nfserr = nfsd4_encode_entry4_fattr(cd, name, namlen);
3812 	switch (nfserr) {
3813 	case nfs_ok:
3814 		break;
3815 	case nfserr_resource:
3816 		nfserr = nfserr_toosmall;
3817 		goto fail;
3818 	case nfserr_noent:
3819 		xdr_truncate_encode(xdr, start_offset);
3820 		goto skip_entry;
3821 	case nfserr_jukebox:
3822 		/*
3823 		 * The pseudoroot should only display dentries that lead to
3824 		 * exports. If we get EJUKEBOX here, then we can't tell whether
3825 		 * this entry should be included. Just fail the whole READDIR
3826 		 * with NFS4ERR_DELAY in that case, and hope that the situation
3827 		 * will resolve itself by the client's next attempt.
3828 		 */
3829 		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
3830 			goto fail;
3831 		fallthrough;
3832 	default:
3833 		/*
3834 		 * If the client requested the RDATTR_ERROR attribute,
3835 		 * we stuff the error code into this attribute
3836 		 * and continue.  If this attribute was not requested,
3837 		 * then in accordance with the spec, we fail the
3838 		 * entire READDIR operation(!)
3839 		 */
3840 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3841 			goto fail;
3842 		if (nfsd4_encode_entry4_rdattr_error(xdr, nfserr)) {
3843 			nfserr = nfserr_toosmall;
3844 			goto fail;
3845 		}
3846 	}
3847 	nfserr = nfserr_toosmall;
3848 	entry_bytes = xdr->buf->len - start_offset;
3849 	if (entry_bytes > cd->rd_maxcount)
3850 		goto fail;
3851 	cd->rd_maxcount -= entry_bytes;
3852 	/*
3853 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
3854 	 * notes that it could be zero. If it is zero, then the server
3855 	 * should enforce only the rd_maxcount value.
3856 	 */
3857 	if (cd->rd_dircount) {
3858 		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3859 		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3860 			goto fail;
3861 		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3862 		if (!cd->rd_dircount)
3863 			cd->rd_maxcount = 0;
3864 	}
3865 
3866 	cd->cookie_offset = cookie_offset;
3867 skip_entry:
3868 	cd->common.err = nfs_ok;
3869 	return 0;
3870 fail:
3871 	xdr_truncate_encode(xdr, start_offset);
3872 	cd->common.err = nfserr;
3873 	return -EINVAL;
3874 }
3875 
3876 static __be32
3877 nfsd4_encode_verifier4(struct xdr_stream *xdr, const nfs4_verifier *verf)
3878 {
3879 	__be32 *p;
3880 
3881 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3882 	if (!p)
3883 		return nfserr_resource;
3884 	memcpy(p, verf->data, sizeof(verf->data));
3885 	return nfs_ok;
3886 }
3887 
3888 static __be32
3889 nfsd4_encode_clientid4(struct xdr_stream *xdr, const clientid_t *clientid)
3890 {
3891 	__be32 *p;
3892 
3893 	p = xdr_reserve_space(xdr, sizeof(__be64));
3894 	if (!p)
3895 		return nfserr_resource;
3896 	memcpy(p, clientid, sizeof(*clientid));
3897 	return nfs_ok;
3898 }
3899 
3900 /* This is a frequently-encoded item; open-coded for speed */
3901 static __be32
3902 nfsd4_encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
3903 {
3904 	__be32 *p;
3905 
3906 	p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
3907 	if (!p)
3908 		return nfserr_resource;
3909 	*p++ = cpu_to_be32(sid->si_generation);
3910 	memcpy(p, &sid->si_opaque, sizeof(sid->si_opaque));
3911 	return nfs_ok;
3912 }
3913 
3914 static __be32
3915 nfsd4_encode_sessionid4(struct xdr_stream *xdr,
3916 			const struct nfs4_sessionid *sessionid)
3917 {
3918 	return nfsd4_encode_opaque_fixed(xdr, sessionid->data,
3919 					 NFS4_MAX_SESSIONID_LEN);
3920 }
3921 
3922 static __be32
3923 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr,
3924 		    union nfsd4_op_u *u)
3925 {
3926 	struct nfsd4_access *access = &u->access;
3927 	struct xdr_stream *xdr = resp->xdr;
3928 	__be32 status;
3929 
3930 	/* supported */
3931 	status = nfsd4_encode_uint32_t(xdr, access->ac_supported);
3932 	if (status != nfs_ok)
3933 		return status;
3934 	/* access */
3935 	return nfsd4_encode_uint32_t(xdr, access->ac_resp_access);
3936 }
3937 
3938 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr,
3939 						union nfsd4_op_u *u)
3940 {
3941 	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
3942 	struct xdr_stream *xdr = resp->xdr;
3943 
3944 	/* bctsr_sessid */
3945 	nfserr = nfsd4_encode_sessionid4(xdr, &bcts->sessionid);
3946 	if (nfserr != nfs_ok)
3947 		return nfserr;
3948 	/* bctsr_dir */
3949 	if (xdr_stream_encode_u32(xdr, bcts->dir) != XDR_UNIT)
3950 		return nfserr_resource;
3951 	/* bctsr_use_conn_in_rdma_mode */
3952 	return nfsd4_encode_bool(xdr, false);
3953 }
3954 
3955 static __be32
3956 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr,
3957 		   union nfsd4_op_u *u)
3958 {
3959 	struct nfsd4_close *close = &u->close;
3960 	struct xdr_stream *xdr = resp->xdr;
3961 
3962 	/* open_stateid */
3963 	return nfsd4_encode_stateid4(xdr, &close->cl_stateid);
3964 }
3965 
3966 
3967 static __be32
3968 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr,
3969 		    union nfsd4_op_u *u)
3970 {
3971 	struct nfsd4_commit *commit = &u->commit;
3972 
3973 	return nfsd4_encode_verifier4(resp->xdr, &commit->co_verf);
3974 }
3975 
3976 static __be32
3977 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr,
3978 		    union nfsd4_op_u *u)
3979 {
3980 	struct nfsd4_create *create = &u->create;
3981 	struct xdr_stream *xdr = resp->xdr;
3982 
3983 	/* cinfo */
3984 	nfserr = nfsd4_encode_change_info4(xdr, &create->cr_cinfo);
3985 	if (nfserr)
3986 		return nfserr;
3987 	/* attrset */
3988 	return nfsd4_encode_bitmap4(xdr, create->cr_bmval[0],
3989 				    create->cr_bmval[1], create->cr_bmval[2]);
3990 }
3991 
3992 static __be32
3993 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr,
3994 		     union nfsd4_op_u *u)
3995 {
3996 	struct nfsd4_getattr *getattr = &u->getattr;
3997 	struct svc_fh *fhp = getattr->ga_fhp;
3998 	struct xdr_stream *xdr = resp->xdr;
3999 
4000 	/* obj_attributes */
4001 	return nfsd4_encode_fattr4(resp->rqstp, xdr, fhp, fhp->fh_export,
4002 				   fhp->fh_dentry, getattr->ga_bmval, 0);
4003 }
4004 
4005 static __be32
4006 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr,
4007 		   union nfsd4_op_u *u)
4008 {
4009 	struct xdr_stream *xdr = resp->xdr;
4010 	struct svc_fh *fhp = u->getfh;
4011 
4012 	/* object */
4013 	return nfsd4_encode_nfs_fh4(xdr, &fhp->fh_handle);
4014 }
4015 
4016 static __be32
4017 nfsd4_encode_lock_owner4(struct xdr_stream *xdr, const clientid_t *clientid,
4018 			 const struct xdr_netobj *owner)
4019 {
4020 	__be32 status;
4021 
4022 	/* clientid */
4023 	status = nfsd4_encode_clientid4(xdr, clientid);
4024 	if (status != nfs_ok)
4025 		return status;
4026 	/* owner */
4027 	return nfsd4_encode_opaque(xdr, owner->data, owner->len);
4028 }
4029 
4030 static __be32
4031 nfsd4_encode_lock4denied(struct xdr_stream *xdr,
4032 			 const struct nfsd4_lock_denied *ld)
4033 {
4034 	__be32 status;
4035 
4036 	/* offset */
4037 	status = nfsd4_encode_offset4(xdr, ld->ld_start);
4038 	if (status != nfs_ok)
4039 		return status;
4040 	/* length */
4041 	status = nfsd4_encode_length4(xdr, ld->ld_length);
4042 	if (status != nfs_ok)
4043 		return status;
4044 	/* locktype */
4045 	if (xdr_stream_encode_u32(xdr, ld->ld_type) != XDR_UNIT)
4046 		return nfserr_resource;
4047 	/* owner */
4048 	return nfsd4_encode_lock_owner4(xdr, &ld->ld_clientid,
4049 					&ld->ld_owner);
4050 }
4051 
4052 static __be32
4053 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr,
4054 		  union nfsd4_op_u *u)
4055 {
4056 	struct nfsd4_lock *lock = &u->lock;
4057 	struct xdr_stream *xdr = resp->xdr;
4058 	__be32 status;
4059 
4060 	switch (nfserr) {
4061 	case nfs_ok:
4062 		/* resok4 */
4063 		status = nfsd4_encode_stateid4(xdr, &lock->lk_resp_stateid);
4064 		break;
4065 	case nfserr_denied:
4066 		/* denied */
4067 		status = nfsd4_encode_lock4denied(xdr, &lock->lk_denied);
4068 		break;
4069 	default:
4070 		return nfserr;
4071 	}
4072 	return status != nfs_ok ? status : nfserr;
4073 }
4074 
4075 static __be32
4076 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr,
4077 		   union nfsd4_op_u *u)
4078 {
4079 	struct nfsd4_lockt *lockt = &u->lockt;
4080 	struct xdr_stream *xdr = resp->xdr;
4081 	__be32 status;
4082 
4083 	if (nfserr == nfserr_denied) {
4084 		/* denied */
4085 		status = nfsd4_encode_lock4denied(xdr, &lockt->lt_denied);
4086 		if (status != nfs_ok)
4087 			return status;
4088 	}
4089 	return nfserr;
4090 }
4091 
4092 static __be32
4093 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr,
4094 		   union nfsd4_op_u *u)
4095 {
4096 	struct nfsd4_locku *locku = &u->locku;
4097 	struct xdr_stream *xdr = resp->xdr;
4098 
4099 	/* lock_stateid */
4100 	return nfsd4_encode_stateid4(xdr, &locku->lu_stateid);
4101 }
4102 
4103 
4104 static __be32
4105 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr,
4106 		  union nfsd4_op_u *u)
4107 {
4108 	struct nfsd4_link *link = &u->link;
4109 	struct xdr_stream *xdr = resp->xdr;
4110 
4111 	return nfsd4_encode_change_info4(xdr, &link->li_cinfo);
4112 }
4113 
4114 /*
4115  * This implementation does not yet support returning an ACE in an
4116  * OPEN that offers a delegation.
4117  */
4118 static __be32
4119 nfsd4_encode_open_nfsace4(struct xdr_stream *xdr)
4120 {
4121 	__be32 status;
4122 
4123 	/* type */
4124 	status = nfsd4_encode_acetype4(xdr, NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
4125 	if (status != nfs_ok)
4126 		return nfserr_resource;
4127 	/* flag */
4128 	status = nfsd4_encode_aceflag4(xdr, 0);
4129 	if (status != nfs_ok)
4130 		return nfserr_resource;
4131 	/* access mask */
4132 	status = nfsd4_encode_acemask4(xdr, 0);
4133 	if (status != nfs_ok)
4134 		return nfserr_resource;
4135 	/* who - empty for now */
4136 	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
4137 		return nfserr_resource;
4138 	return nfs_ok;
4139 }
4140 
4141 static __be32
4142 nfsd4_encode_open_read_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
4143 {
4144 	__be32 status;
4145 
4146 	/* stateid */
4147 	status = nfsd4_encode_stateid4(xdr, &open->op_delegate_stateid);
4148 	if (status != nfs_ok)
4149 		return status;
4150 	/* recall */
4151 	status = nfsd4_encode_bool(xdr, open->op_recall);
4152 	if (status != nfs_ok)
4153 		return status;
4154 	/* permissions */
4155 	return nfsd4_encode_open_nfsace4(xdr);
4156 }
4157 
4158 static __be32
4159 nfsd4_encode_nfs_space_limit4(struct xdr_stream *xdr, u64 filesize)
4160 {
4161 	/* limitby */
4162 	if (xdr_stream_encode_u32(xdr, NFS4_LIMIT_SIZE) != XDR_UNIT)
4163 		return nfserr_resource;
4164 	/* filesize */
4165 	return nfsd4_encode_uint64_t(xdr, filesize);
4166 }
4167 
4168 static __be32
4169 nfsd4_encode_open_write_delegation4(struct xdr_stream *xdr,
4170 				    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 	/* space_limit */
4183 	status = nfsd4_encode_nfs_space_limit4(xdr, 0);
4184 	if (status != nfs_ok)
4185 		return status;
4186 	return nfsd4_encode_open_nfsace4(xdr);
4187 }
4188 
4189 static __be32
4190 nfsd4_encode_open_none_delegation4(struct xdr_stream *xdr,
4191 				   struct nfsd4_open *open)
4192 {
4193 	__be32 status = nfs_ok;
4194 
4195 	/* ond_why */
4196 	if (xdr_stream_encode_u32(xdr, open->op_why_no_deleg) != XDR_UNIT)
4197 		return nfserr_resource;
4198 	switch (open->op_why_no_deleg) {
4199 	case WND4_CONTENTION:
4200 		/* ond_server_will_push_deleg */
4201 		status = nfsd4_encode_bool(xdr, false);
4202 		break;
4203 	case WND4_RESOURCE:
4204 		/* ond_server_will_signal_avail */
4205 		status = nfsd4_encode_bool(xdr, false);
4206 	}
4207 	return status;
4208 }
4209 
4210 static __be32
4211 nfsd4_encode_open_delegation4(struct xdr_stream *xdr, struct nfsd4_open *open)
4212 {
4213 	__be32 status;
4214 
4215 	/* delegation_type */
4216 	if (xdr_stream_encode_u32(xdr, open->op_delegate_type) != XDR_UNIT)
4217 		return nfserr_resource;
4218 	switch (open->op_delegate_type) {
4219 	case NFS4_OPEN_DELEGATE_NONE:
4220 		status = nfs_ok;
4221 		break;
4222 	case NFS4_OPEN_DELEGATE_READ:
4223 		/* read */
4224 		status = nfsd4_encode_open_read_delegation4(xdr, open);
4225 		break;
4226 	case NFS4_OPEN_DELEGATE_WRITE:
4227 		/* write */
4228 		status = nfsd4_encode_open_write_delegation4(xdr, open);
4229 		break;
4230 	case NFS4_OPEN_DELEGATE_NONE_EXT:
4231 		/* od_whynone */
4232 		status = nfsd4_encode_open_none_delegation4(xdr, open);
4233 		break;
4234 	default:
4235 		status = nfserr_serverfault;
4236 	}
4237 
4238 	return status;
4239 }
4240 
4241 static __be32
4242 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
4243 		  union nfsd4_op_u *u)
4244 {
4245 	struct nfsd4_open *open = &u->open;
4246 	struct xdr_stream *xdr = resp->xdr;
4247 
4248 	/* stateid */
4249 	nfserr = nfsd4_encode_stateid4(xdr, &open->op_stateid);
4250 	if (nfserr != nfs_ok)
4251 		return nfserr;
4252 	/* cinfo */
4253 	nfserr = nfsd4_encode_change_info4(xdr, &open->op_cinfo);
4254 	if (nfserr != nfs_ok)
4255 		return nfserr;
4256 	/* rflags */
4257 	nfserr = nfsd4_encode_uint32_t(xdr, open->op_rflags);
4258 	if (nfserr != nfs_ok)
4259 		return nfserr;
4260 	/* attrset */
4261 	nfserr = nfsd4_encode_bitmap4(xdr, open->op_bmval[0],
4262 				      open->op_bmval[1], open->op_bmval[2]);
4263 	if (nfserr != nfs_ok)
4264 		return nfserr;
4265 	/* delegation */
4266 	return nfsd4_encode_open_delegation4(xdr, open);
4267 }
4268 
4269 static __be32
4270 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr,
4271 			  union nfsd4_op_u *u)
4272 {
4273 	struct nfsd4_open_confirm *oc = &u->open_confirm;
4274 	struct xdr_stream *xdr = resp->xdr;
4275 
4276 	/* open_stateid */
4277 	return nfsd4_encode_stateid4(xdr, &oc->oc_resp_stateid);
4278 }
4279 
4280 static __be32
4281 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr,
4282 			    union nfsd4_op_u *u)
4283 {
4284 	struct nfsd4_open_downgrade *od = &u->open_downgrade;
4285 	struct xdr_stream *xdr = resp->xdr;
4286 
4287 	/* open_stateid */
4288 	return nfsd4_encode_stateid4(xdr, &od->od_stateid);
4289 }
4290 
4291 /*
4292  * The operation of this function assumes that this is the only
4293  * READ operation in the COMPOUND. If there are multiple READs,
4294  * we use nfsd4_encode_readv().
4295  */
4296 static __be32 nfsd4_encode_splice_read(
4297 				struct nfsd4_compoundres *resp,
4298 				struct nfsd4_read *read,
4299 				struct file *file, unsigned long maxcount)
4300 {
4301 	struct xdr_stream *xdr = resp->xdr;
4302 	struct xdr_buf *buf = xdr->buf;
4303 	int status, space_left;
4304 	__be32 nfserr;
4305 
4306 	/*
4307 	 * Make sure there is room at the end of buf->head for
4308 	 * svcxdr_encode_opaque_pages() to create a tail buffer
4309 	 * to XDR-pad the payload.
4310 	 */
4311 	if (xdr->iov != xdr->buf->head || xdr->end - xdr->p < 1)
4312 		return nfserr_resource;
4313 
4314 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
4315 				  file, read->rd_offset, &maxcount,
4316 				  &read->rd_eof);
4317 	read->rd_length = maxcount;
4318 	if (nfserr)
4319 		goto out_err;
4320 	svcxdr_encode_opaque_pages(read->rd_rqstp, xdr, buf->pages,
4321 				   buf->page_base, maxcount);
4322 	status = svc_encode_result_payload(read->rd_rqstp,
4323 					   buf->head[0].iov_len, maxcount);
4324 	if (status) {
4325 		nfserr = nfserrno(status);
4326 		goto out_err;
4327 	}
4328 
4329 	/*
4330 	 * Prepare to encode subsequent operations.
4331 	 *
4332 	 * xdr_truncate_encode() is not safe to use after a successful
4333 	 * splice read has been done, so the following stream
4334 	 * manipulations are open-coded.
4335 	 */
4336 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
4337 				buf->buflen - buf->len);
4338 	buf->buflen = buf->len + space_left;
4339 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
4340 
4341 	return nfs_ok;
4342 
4343 out_err:
4344 	/*
4345 	 * nfsd_splice_actor may have already messed with the
4346 	 * page length; reset it so as not to confuse
4347 	 * xdr_truncate_encode in our caller.
4348 	 */
4349 	buf->page_len = 0;
4350 	return nfserr;
4351 }
4352 
4353 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
4354 				 struct nfsd4_read *read,
4355 				 struct file *file, unsigned long maxcount)
4356 {
4357 	struct xdr_stream *xdr = resp->xdr;
4358 	unsigned int base = xdr->buf->page_len & ~PAGE_MASK;
4359 	unsigned int starting_len = xdr->buf->len;
4360 	__be32 zero = xdr_zero;
4361 	__be32 nfserr;
4362 
4363 	if (xdr_reserve_space_vec(xdr, maxcount) < 0)
4364 		return nfserr_resource;
4365 
4366 	nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, file,
4367 				read->rd_offset, &maxcount, base,
4368 				&read->rd_eof);
4369 	read->rd_length = maxcount;
4370 	if (nfserr)
4371 		return nfserr;
4372 	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
4373 		return nfserr_io;
4374 	xdr_truncate_encode(xdr, starting_len + xdr_align_size(maxcount));
4375 
4376 	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
4377 			       xdr_pad_size(maxcount));
4378 	return nfs_ok;
4379 }
4380 
4381 static __be32
4382 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
4383 		  union nfsd4_op_u *u)
4384 {
4385 	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
4386 	struct nfsd4_read *read = &u->read;
4387 	struct xdr_stream *xdr = resp->xdr;
4388 	int starting_len = xdr->buf->len;
4389 	bool splice_ok = argp->splice_ok;
4390 	unsigned long maxcount;
4391 	struct file *file;
4392 	__be32 *p;
4393 
4394 	if (nfserr)
4395 		return nfserr;
4396 	file = read->rd_nf->nf_file;
4397 
4398 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
4399 	if (!p) {
4400 		WARN_ON_ONCE(splice_ok);
4401 		return nfserr_resource;
4402 	}
4403 	if (resp->xdr->buf->page_len && splice_ok) {
4404 		WARN_ON_ONCE(1);
4405 		return nfserr_serverfault;
4406 	}
4407 	xdr_commit_encode(xdr);
4408 
4409 	maxcount = min_t(unsigned long, read->rd_length,
4410 			 (xdr->buf->buflen - xdr->buf->len));
4411 
4412 	if (file->f_op->splice_read && splice_ok)
4413 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
4414 	else
4415 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
4416 	if (nfserr) {
4417 		xdr_truncate_encode(xdr, starting_len);
4418 		return nfserr;
4419 	}
4420 
4421 	p = xdr_encode_bool(p, read->rd_eof);
4422 	*p = cpu_to_be32(read->rd_length);
4423 	return nfs_ok;
4424 }
4425 
4426 static __be32
4427 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr,
4428 		      union nfsd4_op_u *u)
4429 {
4430 	struct nfsd4_readlink *readlink = &u->readlink;
4431 	__be32 *p, *maxcount_p, zero = xdr_zero;
4432 	struct xdr_stream *xdr = resp->xdr;
4433 	int length_offset = xdr->buf->len;
4434 	int maxcount, status;
4435 
4436 	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
4437 	if (!maxcount_p)
4438 		return nfserr_resource;
4439 	maxcount = PAGE_SIZE;
4440 
4441 	p = xdr_reserve_space(xdr, maxcount);
4442 	if (!p)
4443 		return nfserr_resource;
4444 	/*
4445 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
4446 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
4447 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
4448 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
4449 	 */
4450 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
4451 						(char *)p, &maxcount);
4452 	if (nfserr == nfserr_isdir)
4453 		nfserr = nfserr_inval;
4454 	if (nfserr)
4455 		goto out_err;
4456 	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
4457 					   maxcount);
4458 	if (status) {
4459 		nfserr = nfserrno(status);
4460 		goto out_err;
4461 	}
4462 	*maxcount_p = cpu_to_be32(maxcount);
4463 	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
4464 	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
4465 			       xdr_pad_size(maxcount));
4466 	return nfs_ok;
4467 
4468 out_err:
4469 	xdr_truncate_encode(xdr, length_offset);
4470 	return nfserr;
4471 }
4472 
4473 static __be32 nfsd4_encode_dirlist4(struct xdr_stream *xdr,
4474 				    struct nfsd4_readdir *readdir,
4475 				    u32 max_payload)
4476 {
4477 	int bytes_left, maxcount, starting_len = xdr->buf->len;
4478 	loff_t offset;
4479 	__be32 status;
4480 
4481 	/*
4482 	 * Number of bytes left for directory entries allowing for the
4483 	 * final 8 bytes of the readdir and a following failed op.
4484 	 */
4485 	bytes_left = xdr->buf->buflen - xdr->buf->len -
4486 		COMPOUND_ERR_SLACK_SPACE - XDR_UNIT * 2;
4487 	if (bytes_left < 0)
4488 		return nfserr_resource;
4489 	maxcount = min_t(u32, readdir->rd_maxcount, max_payload);
4490 
4491 	/*
4492 	 * The RFC defines rd_maxcount as the size of the
4493 	 * READDIR4resok structure, which includes the verifier
4494 	 * and the 8 bytes encoded at the end of this function.
4495 	 */
4496 	if (maxcount < XDR_UNIT * 4)
4497 		return nfserr_toosmall;
4498 	maxcount = min_t(int, maxcount - XDR_UNIT * 4, bytes_left);
4499 
4500 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0 */
4501 	if (!readdir->rd_dircount)
4502 		readdir->rd_dircount = max_payload;
4503 
4504 	/* *entries */
4505 	readdir->xdr = xdr;
4506 	readdir->rd_maxcount = maxcount;
4507 	readdir->common.err = 0;
4508 	readdir->cookie_offset = 0;
4509 	offset = readdir->rd_cookie;
4510 	status = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp, &offset,
4511 			      &readdir->common, nfsd4_encode_entry4);
4512 	if (status)
4513 		return status;
4514 	if (readdir->common.err == nfserr_toosmall &&
4515 	    xdr->buf->len == starting_len) {
4516 		/* No entries were encoded. Which limit did we hit? */
4517 		if (maxcount - XDR_UNIT * 4 < bytes_left)
4518 			/* It was the fault of rd_maxcount */
4519 			return nfserr_toosmall;
4520 		/* We ran out of buffer space */
4521 		return nfserr_resource;
4522 	}
4523 	/* Encode the final entry's cookie value */
4524 	nfsd4_encode_entry4_nfs_cookie4(readdir, offset);
4525 	/* No entries follow */
4526 	if (xdr_stream_encode_item_absent(xdr) != XDR_UNIT)
4527 		return nfserr_resource;
4528 
4529 	/* eof */
4530 	return nfsd4_encode_bool(xdr, readdir->common.err == nfserr_eof);
4531 }
4532 
4533 static __be32
4534 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr,
4535 		     union nfsd4_op_u *u)
4536 {
4537 	struct nfsd4_readdir *readdir = &u->readdir;
4538 	struct xdr_stream *xdr = resp->xdr;
4539 	int starting_len = xdr->buf->len;
4540 
4541 	/* cookieverf */
4542 	nfserr = nfsd4_encode_verifier4(xdr, &readdir->rd_verf);
4543 	if (nfserr != nfs_ok)
4544 		return nfserr;
4545 
4546 	/* reply */
4547 	nfserr = nfsd4_encode_dirlist4(xdr, readdir, svc_max_payload(resp->rqstp));
4548 	if (nfserr != nfs_ok)
4549 		xdr_truncate_encode(xdr, starting_len);
4550 	return nfserr;
4551 }
4552 
4553 static __be32
4554 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr,
4555 		    union nfsd4_op_u *u)
4556 {
4557 	struct nfsd4_remove *remove = &u->remove;
4558 	struct xdr_stream *xdr = resp->xdr;
4559 
4560 	return nfsd4_encode_change_info4(xdr, &remove->rm_cinfo);
4561 }
4562 
4563 static __be32
4564 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr,
4565 		    union nfsd4_op_u *u)
4566 {
4567 	struct nfsd4_rename *rename = &u->rename;
4568 	struct xdr_stream *xdr = resp->xdr;
4569 
4570 	nfserr = nfsd4_encode_change_info4(xdr, &rename->rn_sinfo);
4571 	if (nfserr)
4572 		return nfserr;
4573 	return nfsd4_encode_change_info4(xdr, &rename->rn_tinfo);
4574 }
4575 
4576 static __be32
4577 nfsd4_encode_rpcsec_gss_info(struct xdr_stream *xdr,
4578 			     struct rpcsec_gss_info *info)
4579 {
4580 	__be32 status;
4581 
4582 	/* oid */
4583 	if (xdr_stream_encode_opaque(xdr, info->oid.data, info->oid.len) < 0)
4584 		return nfserr_resource;
4585 	/* qop */
4586 	status = nfsd4_encode_qop4(xdr, info->qop);
4587 	if (status != nfs_ok)
4588 		return status;
4589 	/* service */
4590 	if (xdr_stream_encode_u32(xdr, info->service) != XDR_UNIT)
4591 		return nfserr_resource;
4592 
4593 	return nfs_ok;
4594 }
4595 
4596 static __be32
4597 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
4598 {
4599 	u32 i, nflavs, supported;
4600 	struct exp_flavor_info *flavs;
4601 	struct exp_flavor_info def_flavs[2];
4602 	static bool report = true;
4603 	__be32 *flavorsp;
4604 	__be32 status;
4605 
4606 	if (exp->ex_nflavors) {
4607 		flavs = exp->ex_flavors;
4608 		nflavs = exp->ex_nflavors;
4609 	} else { /* Handling of some defaults in absence of real secinfo: */
4610 		flavs = def_flavs;
4611 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
4612 			nflavs = 2;
4613 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
4614 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
4615 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
4616 			nflavs = 1;
4617 			flavs[0].pseudoflavor
4618 					= svcauth_gss_flavor(exp->ex_client);
4619 		} else {
4620 			nflavs = 1;
4621 			flavs[0].pseudoflavor
4622 					= exp->ex_client->flavour->flavour;
4623 		}
4624 	}
4625 
4626 	supported = 0;
4627 	flavorsp = xdr_reserve_space(xdr, XDR_UNIT);
4628 	if (!flavorsp)
4629 		return nfserr_resource;
4630 
4631 	for (i = 0; i < nflavs; i++) {
4632 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
4633 		struct rpcsec_gss_info info;
4634 
4635 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
4636 			supported++;
4637 
4638 			/* flavor */
4639 			status = nfsd4_encode_uint32_t(xdr, RPC_AUTH_GSS);
4640 			if (status != nfs_ok)
4641 				return status;
4642 			/* flavor_info */
4643 			status = nfsd4_encode_rpcsec_gss_info(xdr, &info);
4644 			if (status != nfs_ok)
4645 				return status;
4646 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
4647 			supported++;
4648 
4649 			/* flavor */
4650 			status = nfsd4_encode_uint32_t(xdr, pf);
4651 			if (status != nfs_ok)
4652 				return status;
4653 		} else {
4654 			if (report)
4655 				pr_warn("NFS: SECINFO: security flavor %u "
4656 					"is not supported\n", pf);
4657 		}
4658 	}
4659 
4660 	if (nflavs != supported)
4661 		report = false;
4662 	*flavorsp = cpu_to_be32(supported);
4663 	return 0;
4664 }
4665 
4666 static __be32
4667 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4668 		     union nfsd4_op_u *u)
4669 {
4670 	struct nfsd4_secinfo *secinfo = &u->secinfo;
4671 	struct xdr_stream *xdr = resp->xdr;
4672 
4673 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
4674 }
4675 
4676 static __be32
4677 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
4678 		     union nfsd4_op_u *u)
4679 {
4680 	struct nfsd4_secinfo_no_name *secinfo = &u->secinfo_no_name;
4681 	struct xdr_stream *xdr = resp->xdr;
4682 
4683 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
4684 }
4685 
4686 static __be32
4687 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr,
4688 		     union nfsd4_op_u *u)
4689 {
4690 	struct nfsd4_setattr *setattr = &u->setattr;
4691 	__be32 status;
4692 
4693 	switch (nfserr) {
4694 	case nfs_ok:
4695 		/* attrsset */
4696 		status = nfsd4_encode_bitmap4(resp->xdr, setattr->sa_bmval[0],
4697 					      setattr->sa_bmval[1],
4698 					      setattr->sa_bmval[2]);
4699 		break;
4700 	default:
4701 		/* attrsset */
4702 		status = nfsd4_encode_bitmap4(resp->xdr, 0, 0, 0);
4703 	}
4704 	return status != nfs_ok ? status : nfserr;
4705 }
4706 
4707 static __be32
4708 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr,
4709 			 union nfsd4_op_u *u)
4710 {
4711 	struct nfsd4_setclientid *scd = &u->setclientid;
4712 	struct xdr_stream *xdr = resp->xdr;
4713 
4714 	if (!nfserr) {
4715 		nfserr = nfsd4_encode_clientid4(xdr, &scd->se_clientid);
4716 		if (nfserr != nfs_ok)
4717 			goto out;
4718 		nfserr = nfsd4_encode_verifier4(xdr, &scd->se_confirm);
4719 	} else if (nfserr == nfserr_clid_inuse) {
4720 		/* empty network id */
4721 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4722 			nfserr = nfserr_resource;
4723 			goto out;
4724 		}
4725 		/* empty universal address */
4726 		if (xdr_stream_encode_u32(xdr, 0) < 0) {
4727 			nfserr = nfserr_resource;
4728 			goto out;
4729 		}
4730 	}
4731 out:
4732 	return nfserr;
4733 }
4734 
4735 static __be32
4736 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr,
4737 		   union nfsd4_op_u *u)
4738 {
4739 	struct nfsd4_write *write = &u->write;
4740 	struct xdr_stream *xdr = resp->xdr;
4741 
4742 	/* count */
4743 	nfserr = nfsd4_encode_count4(xdr, write->wr_bytes_written);
4744 	if (nfserr)
4745 		return nfserr;
4746 	/* committed */
4747 	if (xdr_stream_encode_u32(xdr, write->wr_how_written) != XDR_UNIT)
4748 		return nfserr_resource;
4749 	/* writeverf */
4750 	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
4751 }
4752 
4753 static __be32
4754 nfsd4_encode_state_protect_ops4(struct xdr_stream *xdr,
4755 				struct nfsd4_exchange_id *exid)
4756 {
4757 	__be32 status;
4758 
4759 	/* spo_must_enforce */
4760 	status = nfsd4_encode_bitmap4(xdr, exid->spo_must_enforce[0],
4761 				      exid->spo_must_enforce[1],
4762 				      exid->spo_must_enforce[2]);
4763 	if (status != nfs_ok)
4764 		return status;
4765 	/* spo_must_allow */
4766 	return nfsd4_encode_bitmap4(xdr, exid->spo_must_allow[0],
4767 				    exid->spo_must_allow[1],
4768 				    exid->spo_must_allow[2]);
4769 }
4770 
4771 static __be32
4772 nfsd4_encode_state_protect4_r(struct xdr_stream *xdr, struct nfsd4_exchange_id *exid)
4773 {
4774 	__be32 status;
4775 
4776 	if (xdr_stream_encode_u32(xdr, exid->spa_how) != XDR_UNIT)
4777 		return nfserr_resource;
4778 	switch (exid->spa_how) {
4779 	case SP4_NONE:
4780 		status = nfs_ok;
4781 		break;
4782 	case SP4_MACH_CRED:
4783 		/* spr_mach_ops */
4784 		status = nfsd4_encode_state_protect_ops4(xdr, exid);
4785 		break;
4786 	default:
4787 		status = nfserr_serverfault;
4788 	}
4789 	return status;
4790 }
4791 
4792 static __be32
4793 nfsd4_encode_server_owner4(struct xdr_stream *xdr, struct svc_rqst *rqstp)
4794 {
4795 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
4796 	__be32 status;
4797 
4798 	/* so_minor_id */
4799 	status = nfsd4_encode_uint64_t(xdr, 0);
4800 	if (status != nfs_ok)
4801 		return status;
4802 	/* so_major_id */
4803 	return nfsd4_encode_opaque(xdr, nn->nfsd_name, strlen(nn->nfsd_name));
4804 }
4805 
4806 static __be32
4807 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4808 			 union nfsd4_op_u *u)
4809 {
4810 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4811 	struct nfsd4_exchange_id *exid = &u->exchange_id;
4812 	struct xdr_stream *xdr = resp->xdr;
4813 
4814 	/* eir_clientid */
4815 	nfserr = nfsd4_encode_clientid4(xdr, &exid->clientid);
4816 	if (nfserr != nfs_ok)
4817 		return nfserr;
4818 	/* eir_sequenceid */
4819 	nfserr = nfsd4_encode_sequenceid4(xdr, exid->seqid);
4820 	if (nfserr != nfs_ok)
4821 		return nfserr;
4822 	/* eir_flags */
4823 	nfserr = nfsd4_encode_uint32_t(xdr, exid->flags);
4824 	if (nfserr != nfs_ok)
4825 		return nfserr;
4826 	/* eir_state_protect */
4827 	nfserr = nfsd4_encode_state_protect4_r(xdr, exid);
4828 	if (nfserr != nfs_ok)
4829 		return nfserr;
4830 	/* eir_server_owner */
4831 	nfserr = nfsd4_encode_server_owner4(xdr, resp->rqstp);
4832 	if (nfserr != nfs_ok)
4833 		return nfserr;
4834 	/* eir_server_scope */
4835 	nfserr = nfsd4_encode_opaque(xdr, nn->nfsd_name,
4836 				     strlen(nn->nfsd_name));
4837 	if (nfserr != nfs_ok)
4838 		return nfserr;
4839 	/* eir_server_impl_id<1> */
4840 	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
4841 		return nfserr_resource;
4842 
4843 	return nfs_ok;
4844 }
4845 
4846 static __be32
4847 nfsd4_encode_channel_attrs4(struct xdr_stream *xdr,
4848 			    const struct nfsd4_channel_attrs *attrs)
4849 {
4850 	__be32 status;
4851 
4852 	/* ca_headerpadsize */
4853 	status = nfsd4_encode_count4(xdr, 0);
4854 	if (status != nfs_ok)
4855 		return status;
4856 	/* ca_maxrequestsize */
4857 	status = nfsd4_encode_count4(xdr, attrs->maxreq_sz);
4858 	if (status != nfs_ok)
4859 		return status;
4860 	/* ca_maxresponsesize */
4861 	status = nfsd4_encode_count4(xdr, attrs->maxresp_sz);
4862 	if (status != nfs_ok)
4863 		return status;
4864 	/* ca_maxresponsesize_cached */
4865 	status = nfsd4_encode_count4(xdr, attrs->maxresp_cached);
4866 	if (status != nfs_ok)
4867 		return status;
4868 	/* ca_maxoperations */
4869 	status = nfsd4_encode_count4(xdr, attrs->maxops);
4870 	if (status != nfs_ok)
4871 		return status;
4872 	/* ca_maxrequests */
4873 	status = nfsd4_encode_count4(xdr, attrs->maxreqs);
4874 	if (status != nfs_ok)
4875 		return status;
4876 	/* ca_rdma_ird<1> */
4877 	if (xdr_stream_encode_u32(xdr, attrs->nr_rdma_attrs) != XDR_UNIT)
4878 		return nfserr_resource;
4879 	if (attrs->nr_rdma_attrs)
4880 		return nfsd4_encode_uint32_t(xdr, attrs->rdma_attrs);
4881 	return nfs_ok;
4882 }
4883 
4884 static __be32
4885 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4886 			    union nfsd4_op_u *u)
4887 {
4888 	struct nfsd4_create_session *sess = &u->create_session;
4889 	struct xdr_stream *xdr = resp->xdr;
4890 
4891 	/* csr_sessionid */
4892 	nfserr = nfsd4_encode_sessionid4(xdr, &sess->sessionid);
4893 	if (nfserr != nfs_ok)
4894 		return nfserr;
4895 	/* csr_sequence */
4896 	nfserr = nfsd4_encode_sequenceid4(xdr, sess->seqid);
4897 	if (nfserr != nfs_ok)
4898 		return nfserr;
4899 	/* csr_flags */
4900 	nfserr = nfsd4_encode_uint32_t(xdr, sess->flags);
4901 	if (nfserr != nfs_ok)
4902 		return nfserr;
4903 	/* csr_fore_chan_attrs */
4904 	nfserr = nfsd4_encode_channel_attrs4(xdr, &sess->fore_channel);
4905 	if (nfserr != nfs_ok)
4906 		return nfserr;
4907 	/* csr_back_chan_attrs */
4908 	return nfsd4_encode_channel_attrs4(xdr, &sess->back_channel);
4909 }
4910 
4911 static __be32
4912 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4913 		      union nfsd4_op_u *u)
4914 {
4915 	struct nfsd4_sequence *seq = &u->sequence;
4916 	struct xdr_stream *xdr = resp->xdr;
4917 
4918 	/* sr_sessionid */
4919 	nfserr = nfsd4_encode_sessionid4(xdr, &seq->sessionid);
4920 	if (nfserr != nfs_ok)
4921 		return nfserr;
4922 	/* sr_sequenceid */
4923 	nfserr = nfsd4_encode_sequenceid4(xdr, seq->seqid);
4924 	if (nfserr != nfs_ok)
4925 		return nfserr;
4926 	/* sr_slotid */
4927 	nfserr = nfsd4_encode_slotid4(xdr, seq->slotid);
4928 	if (nfserr != nfs_ok)
4929 		return nfserr;
4930 	/* Note slotid's are numbered from zero: */
4931 	/* sr_highest_slotid */
4932 	nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots - 1);
4933 	if (nfserr != nfs_ok)
4934 		return nfserr;
4935 	/* sr_target_highest_slotid */
4936 	nfserr = nfsd4_encode_slotid4(xdr, seq->maxslots - 1);
4937 	if (nfserr != nfs_ok)
4938 		return nfserr;
4939 	/* sr_status_flags */
4940 	nfserr = nfsd4_encode_uint32_t(xdr, seq->status_flags);
4941 	if (nfserr != nfs_ok)
4942 		return nfserr;
4943 
4944 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4945 	return nfs_ok;
4946 }
4947 
4948 static __be32
4949 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4950 			  union nfsd4_op_u *u)
4951 {
4952 	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
4953 	struct nfsd4_test_stateid_id *stateid, *next;
4954 	struct xdr_stream *xdr = resp->xdr;
4955 
4956 	/* tsr_status_codes<> */
4957 	if (xdr_stream_encode_u32(xdr, test_stateid->ts_num_ids) != XDR_UNIT)
4958 		return nfserr_resource;
4959 	list_for_each_entry_safe(stateid, next,
4960 				 &test_stateid->ts_stateid_list, ts_id_list) {
4961 		if (xdr_stream_encode_be32(xdr, stateid->ts_id_status) != XDR_UNIT)
4962 			return nfserr_resource;
4963 	}
4964 	return nfs_ok;
4965 }
4966 
4967 #ifdef CONFIG_NFSD_PNFS
4968 static __be32
4969 nfsd4_encode_device_addr4(struct xdr_stream *xdr,
4970 			  const struct nfsd4_getdeviceinfo *gdev)
4971 {
4972 	u32 needed_len, starting_len = xdr->buf->len;
4973 	const struct nfsd4_layout_ops *ops;
4974 	__be32 status;
4975 
4976 	/* da_layout_type */
4977 	if (xdr_stream_encode_u32(xdr, gdev->gd_layout_type) != XDR_UNIT)
4978 		return nfserr_resource;
4979 	/* da_addr_body */
4980 	ops = nfsd4_layout_ops[gdev->gd_layout_type];
4981 	status = ops->encode_getdeviceinfo(xdr, gdev);
4982 	if (status != nfs_ok) {
4983 		/*
4984 		 * Don't burden the layout drivers with enforcing
4985 		 * gd_maxcount. Just tell the client to come back
4986 		 * with a bigger buffer if it's not enough.
4987 		 */
4988 		if (xdr->buf->len + XDR_UNIT > gdev->gd_maxcount)
4989 			goto toosmall;
4990 		return status;
4991 	}
4992 
4993 	return nfs_ok;
4994 
4995 toosmall:
4996 	needed_len = xdr->buf->len + XDR_UNIT;	/* notifications */
4997 	xdr_truncate_encode(xdr, starting_len);
4998 
4999 	status = nfsd4_encode_count4(xdr, needed_len);
5000 	if (status != nfs_ok)
5001 		return status;
5002 	return nfserr_toosmall;
5003 }
5004 
5005 static __be32
5006 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
5007 		union nfsd4_op_u *u)
5008 {
5009 	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
5010 	struct xdr_stream *xdr = resp->xdr;
5011 
5012 	/* gdir_device_addr */
5013 	nfserr = nfsd4_encode_device_addr4(xdr, gdev);
5014 	if (nfserr)
5015 		return nfserr;
5016 	/* gdir_notification */
5017 	return nfsd4_encode_bitmap4(xdr, gdev->gd_notify_types, 0, 0);
5018 }
5019 
5020 static __be32
5021 nfsd4_encode_layout4(struct xdr_stream *xdr, const struct nfsd4_layoutget *lgp)
5022 {
5023 	const struct nfsd4_layout_ops *ops = nfsd4_layout_ops[lgp->lg_layout_type];
5024 	__be32 status;
5025 
5026 	/* lo_offset */
5027 	status = nfsd4_encode_offset4(xdr, lgp->lg_seg.offset);
5028 	if (status != nfs_ok)
5029 		return status;
5030 	/* lo_length */
5031 	status = nfsd4_encode_length4(xdr, lgp->lg_seg.length);
5032 	if (status != nfs_ok)
5033 		return status;
5034 	/* lo_iomode */
5035 	if (xdr_stream_encode_u32(xdr, lgp->lg_seg.iomode) != XDR_UNIT)
5036 		return nfserr_resource;
5037 	/* lo_content */
5038 	if (xdr_stream_encode_u32(xdr, lgp->lg_layout_type) != XDR_UNIT)
5039 		return nfserr_resource;
5040 	return ops->encode_layoutget(xdr, lgp);
5041 }
5042 
5043 static __be32
5044 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
5045 		union nfsd4_op_u *u)
5046 {
5047 	struct nfsd4_layoutget *lgp = &u->layoutget;
5048 	struct xdr_stream *xdr = resp->xdr;
5049 
5050 	/* logr_return_on_close */
5051 	nfserr = nfsd4_encode_bool(xdr, true);
5052 	if (nfserr != nfs_ok)
5053 		return nfserr;
5054 	/* logr_stateid */
5055 	nfserr = nfsd4_encode_stateid4(xdr, &lgp->lg_sid);
5056 	if (nfserr != nfs_ok)
5057 		return nfserr;
5058 	/* logr_layout<> */
5059 	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
5060 		return nfserr_resource;
5061 	return nfsd4_encode_layout4(xdr, lgp);
5062 }
5063 
5064 static __be32
5065 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
5066 			  union nfsd4_op_u *u)
5067 {
5068 	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
5069 	struct xdr_stream *xdr = resp->xdr;
5070 
5071 	/* ns_sizechanged */
5072 	nfserr = nfsd4_encode_bool(xdr, lcp->lc_size_chg);
5073 	if (nfserr != nfs_ok)
5074 		return nfserr;
5075 	if (lcp->lc_size_chg)
5076 		/* ns_size */
5077 		return nfsd4_encode_length4(xdr, lcp->lc_newsize);
5078 	return nfs_ok;
5079 }
5080 
5081 static __be32
5082 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
5083 		union nfsd4_op_u *u)
5084 {
5085 	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
5086 	struct xdr_stream *xdr = resp->xdr;
5087 
5088 	/* lrs_present */
5089 	nfserr = nfsd4_encode_bool(xdr, lrp->lrs_present);
5090 	if (nfserr != nfs_ok)
5091 		return nfserr;
5092 	if (lrp->lrs_present)
5093 		/* lrs_stateid */
5094 		return nfsd4_encode_stateid4(xdr, &lrp->lr_sid);
5095 	return nfs_ok;
5096 }
5097 #endif /* CONFIG_NFSD_PNFS */
5098 
5099 static __be32
5100 nfsd4_encode_write_response4(struct xdr_stream *xdr,
5101 			     const struct nfsd4_copy *copy)
5102 {
5103 	const struct nfsd42_write_res *write = &copy->cp_res;
5104 	u32 count = nfsd4_copy_is_sync(copy) ? 0 : 1;
5105 	__be32 status;
5106 
5107 	/* wr_callback_id<1> */
5108 	if (xdr_stream_encode_u32(xdr, count) != XDR_UNIT)
5109 		return nfserr_resource;
5110 	if (count) {
5111 		status = nfsd4_encode_stateid4(xdr, &write->cb_stateid);
5112 		if (status != nfs_ok)
5113 			return status;
5114 	}
5115 
5116 	/* wr_count */
5117 	status = nfsd4_encode_length4(xdr, write->wr_bytes_written);
5118 	if (status != nfs_ok)
5119 		return status;
5120 	/* wr_committed */
5121 	if (xdr_stream_encode_u32(xdr, write->wr_stable_how) != XDR_UNIT)
5122 		return nfserr_resource;
5123 	/* wr_writeverf */
5124 	return nfsd4_encode_verifier4(xdr, &write->wr_verifier);
5125 }
5126 
5127 static __be32 nfsd4_encode_copy_requirements4(struct xdr_stream *xdr,
5128 					      const struct nfsd4_copy *copy)
5129 {
5130 	__be32 status;
5131 
5132 	/* cr_consecutive */
5133 	status = nfsd4_encode_bool(xdr, true);
5134 	if (status != nfs_ok)
5135 		return status;
5136 	/* cr_synchronous */
5137 	return nfsd4_encode_bool(xdr, nfsd4_copy_is_sync(copy));
5138 }
5139 
5140 static __be32
5141 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
5142 		  union nfsd4_op_u *u)
5143 {
5144 	struct nfsd4_copy *copy = &u->copy;
5145 
5146 	nfserr = nfsd4_encode_write_response4(resp->xdr, copy);
5147 	if (nfserr != nfs_ok)
5148 		return nfserr;
5149 	return nfsd4_encode_copy_requirements4(resp->xdr, copy);
5150 }
5151 
5152 static __be32
5153 nfsd4_encode_netloc4(struct xdr_stream *xdr, const struct nl4_server *ns)
5154 {
5155 	__be32 status;
5156 
5157 	if (xdr_stream_encode_u32(xdr, ns->nl4_type) != XDR_UNIT)
5158 		return nfserr_resource;
5159 	switch (ns->nl4_type) {
5160 	case NL4_NETADDR:
5161 		/* nl_addr */
5162 		status = nfsd4_encode_netaddr4(xdr, &ns->u.nl4_addr);
5163 		break;
5164 	default:
5165 		status = nfserr_serverfault;
5166 	}
5167 	return status;
5168 }
5169 
5170 static __be32
5171 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
5172 			 union nfsd4_op_u *u)
5173 {
5174 	struct nfsd4_copy_notify *cn = &u->copy_notify;
5175 	struct xdr_stream *xdr = resp->xdr;
5176 
5177 	/* cnr_lease_time */
5178 	nfserr = nfsd4_encode_nfstime4(xdr, &cn->cpn_lease_time);
5179 	if (nfserr)
5180 		return nfserr;
5181 	/* cnr_stateid */
5182 	nfserr = nfsd4_encode_stateid4(xdr, &cn->cpn_cnr_stateid);
5183 	if (nfserr)
5184 		return nfserr;
5185 	/* cnr_source_server<> */
5186 	if (xdr_stream_encode_u32(xdr, 1) != XDR_UNIT)
5187 		return nfserr_resource;
5188 	return nfsd4_encode_netloc4(xdr, cn->cpn_src);
5189 }
5190 
5191 static __be32
5192 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
5193 			    union nfsd4_op_u *u)
5194 {
5195 	struct nfsd4_offload_status *os = &u->offload_status;
5196 	struct xdr_stream *xdr = resp->xdr;
5197 
5198 	/* osr_count */
5199 	nfserr = nfsd4_encode_length4(xdr, os->count);
5200 	if (nfserr != nfs_ok)
5201 		return nfserr;
5202 	/* osr_complete<1> */
5203 	if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
5204 		return nfserr_resource;
5205 	return nfs_ok;
5206 }
5207 
5208 static __be32
5209 nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
5210 			    struct nfsd4_read *read)
5211 {
5212 	struct nfsd4_compoundargs *argp = resp->rqstp->rq_argp;
5213 	struct file *file = read->rd_nf->nf_file;
5214 	struct xdr_stream *xdr = resp->xdr;
5215 	bool splice_ok = argp->splice_ok;
5216 	unsigned long maxcount;
5217 	__be32 nfserr, *p;
5218 
5219 	/* Content type, offset, byte count */
5220 	p = xdr_reserve_space(xdr, 4 + 8 + 4);
5221 	if (!p)
5222 		return nfserr_io;
5223 	if (resp->xdr->buf->page_len && splice_ok) {
5224 		WARN_ON_ONCE(splice_ok);
5225 		return nfserr_serverfault;
5226 	}
5227 
5228 	maxcount = min_t(unsigned long, read->rd_length,
5229 			 (xdr->buf->buflen - xdr->buf->len));
5230 
5231 	if (file->f_op->splice_read && splice_ok)
5232 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
5233 	else
5234 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
5235 	if (nfserr)
5236 		return nfserr;
5237 
5238 	*p++ = cpu_to_be32(NFS4_CONTENT_DATA);
5239 	p = xdr_encode_hyper(p, read->rd_offset);
5240 	*p = cpu_to_be32(read->rd_length);
5241 
5242 	return nfs_ok;
5243 }
5244 
5245 static __be32
5246 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
5247 		       union nfsd4_op_u *u)
5248 {
5249 	struct nfsd4_read *read = &u->read;
5250 	struct file *file = read->rd_nf->nf_file;
5251 	struct xdr_stream *xdr = resp->xdr;
5252 	int starting_len = xdr->buf->len;
5253 	u32 segments = 0;
5254 	__be32 *p;
5255 
5256 	if (nfserr)
5257 		return nfserr;
5258 
5259 	/* eof flag, segment count */
5260 	p = xdr_reserve_space(xdr, 4 + 4);
5261 	if (!p)
5262 		return nfserr_io;
5263 	xdr_commit_encode(xdr);
5264 
5265 	read->rd_eof = read->rd_offset >= i_size_read(file_inode(file));
5266 	if (read->rd_eof)
5267 		goto out;
5268 
5269 	nfserr = nfsd4_encode_read_plus_data(resp, read);
5270 	if (nfserr) {
5271 		xdr_truncate_encode(xdr, starting_len);
5272 		return nfserr;
5273 	}
5274 
5275 	segments++;
5276 
5277 out:
5278 	p = xdr_encode_bool(p, read->rd_eof);
5279 	*p = cpu_to_be32(segments);
5280 	return nfserr;
5281 }
5282 
5283 static __be32
5284 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
5285 		  union nfsd4_op_u *u)
5286 {
5287 	struct nfsd4_seek *seek = &u->seek;
5288 	struct xdr_stream *xdr = resp->xdr;
5289 
5290 	/* sr_eof */
5291 	nfserr = nfsd4_encode_bool(xdr, seek->seek_eof);
5292 	if (nfserr != nfs_ok)
5293 		return nfserr;
5294 	/* sr_offset */
5295 	return nfsd4_encode_offset4(xdr, seek->seek_pos);
5296 }
5297 
5298 static __be32
5299 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr,
5300 		  union nfsd4_op_u *p)
5301 {
5302 	return nfserr;
5303 }
5304 
5305 /*
5306  * Encode kmalloc-ed buffer in to XDR stream.
5307  */
5308 static __be32
5309 nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
5310 {
5311 	u32 cplen;
5312 	__be32 *p;
5313 
5314 	cplen = min_t(unsigned long, buflen,
5315 		      ((void *)xdr->end - (void *)xdr->p));
5316 	p = xdr_reserve_space(xdr, cplen);
5317 	if (!p)
5318 		return nfserr_resource;
5319 
5320 	memcpy(p, buf, cplen);
5321 	buf += cplen;
5322 	buflen -= cplen;
5323 
5324 	while (buflen) {
5325 		cplen = min_t(u32, buflen, PAGE_SIZE);
5326 		p = xdr_reserve_space(xdr, cplen);
5327 		if (!p)
5328 			return nfserr_resource;
5329 
5330 		memcpy(p, buf, cplen);
5331 
5332 		if (cplen < PAGE_SIZE) {
5333 			/*
5334 			 * We're done, with a length that wasn't page
5335 			 * aligned, so possibly not word aligned. Pad
5336 			 * any trailing bytes with 0.
5337 			 */
5338 			xdr_encode_opaque_fixed(p, NULL, cplen);
5339 			break;
5340 		}
5341 
5342 		buflen -= PAGE_SIZE;
5343 		buf += PAGE_SIZE;
5344 	}
5345 
5346 	return 0;
5347 }
5348 
5349 static __be32
5350 nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5351 		      union nfsd4_op_u *u)
5352 {
5353 	struct nfsd4_getxattr *getxattr = &u->getxattr;
5354 	struct xdr_stream *xdr = resp->xdr;
5355 	__be32 *p, err;
5356 
5357 	p = xdr_reserve_space(xdr, 4);
5358 	if (!p)
5359 		return nfserr_resource;
5360 
5361 	*p = cpu_to_be32(getxattr->getxa_len);
5362 
5363 	if (getxattr->getxa_len == 0)
5364 		return 0;
5365 
5366 	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
5367 				    getxattr->getxa_len);
5368 
5369 	kvfree(getxattr->getxa_buf);
5370 
5371 	return err;
5372 }
5373 
5374 static __be32
5375 nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5376 		      union nfsd4_op_u *u)
5377 {
5378 	struct nfsd4_setxattr *setxattr = &u->setxattr;
5379 	struct xdr_stream *xdr = resp->xdr;
5380 
5381 	return nfsd4_encode_change_info4(xdr, &setxattr->setxa_cinfo);
5382 }
5383 
5384 /*
5385  * See if there are cookie values that can be rejected outright.
5386  */
5387 static __be32
5388 nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
5389 				u32 *offsetp)
5390 {
5391 	u64 cookie = listxattrs->lsxa_cookie;
5392 
5393 	/*
5394 	 * If the cookie is larger than the maximum number we can fit
5395 	 * in the buffer we just got back from vfs_listxattr, it's invalid.
5396 	 */
5397 	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
5398 		return nfserr_badcookie;
5399 
5400 	*offsetp = (u32)cookie;
5401 	return 0;
5402 }
5403 
5404 static __be32
5405 nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
5406 			union nfsd4_op_u *u)
5407 {
5408 	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
5409 	struct xdr_stream *xdr = resp->xdr;
5410 	u32 cookie_offset, count_offset, eof;
5411 	u32 left, xdrleft, slen, count;
5412 	u32 xdrlen, offset;
5413 	u64 cookie;
5414 	char *sp;
5415 	__be32 status, tmp;
5416 	__be64 wire_cookie;
5417 	__be32 *p;
5418 	u32 nuser;
5419 
5420 	eof = 1;
5421 
5422 	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
5423 	if (status)
5424 		goto out;
5425 
5426 	/*
5427 	 * Reserve space for the cookie and the name array count. Record
5428 	 * the offsets to save them later.
5429 	 */
5430 	cookie_offset = xdr->buf->len;
5431 	count_offset = cookie_offset + 8;
5432 	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
5433 	if (!p) {
5434 		status = nfserr_resource;
5435 		goto out;
5436 	}
5437 
5438 	count = 0;
5439 	left = listxattrs->lsxa_len;
5440 	sp = listxattrs->lsxa_buf;
5441 	nuser = 0;
5442 
5443 	/* Bytes left is maxcount - 8 (cookie) - 4 (array count) */
5444 	xdrleft = listxattrs->lsxa_maxcount - XDR_UNIT * 3;
5445 
5446 	while (left > 0 && xdrleft > 0) {
5447 		slen = strlen(sp);
5448 
5449 		/*
5450 		 * Check if this is a "user." attribute, skip it if not.
5451 		 */
5452 		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
5453 			goto contloop;
5454 
5455 		slen -= XATTR_USER_PREFIX_LEN;
5456 		xdrlen = 4 + ((slen + 3) & ~3);
5457 		/* Check if both entry and eof can fit in the XDR buffer */
5458 		if (xdrlen + XDR_UNIT > xdrleft) {
5459 			if (count == 0) {
5460 				/*
5461 				 * Can't even fit the first attribute name.
5462 				 */
5463 				status = nfserr_toosmall;
5464 				goto out;
5465 			}
5466 			eof = 0;
5467 			goto wreof;
5468 		}
5469 
5470 		left -= XATTR_USER_PREFIX_LEN;
5471 		sp += XATTR_USER_PREFIX_LEN;
5472 		if (nuser++ < offset)
5473 			goto contloop;
5474 
5475 
5476 		p = xdr_reserve_space(xdr, xdrlen);
5477 		if (!p) {
5478 			status = nfserr_resource;
5479 			goto out;
5480 		}
5481 
5482 		xdr_encode_opaque(p, sp, slen);
5483 
5484 		xdrleft -= xdrlen;
5485 		count++;
5486 contloop:
5487 		sp += slen + 1;
5488 		left -= slen + 1;
5489 	}
5490 
5491 	/*
5492 	 * If there were user attributes to copy, but we didn't copy
5493 	 * any, the offset was too large (e.g. the cookie was invalid).
5494 	 */
5495 	if (nuser > 0 && count == 0) {
5496 		status = nfserr_badcookie;
5497 		goto out;
5498 	}
5499 
5500 wreof:
5501 	p = xdr_reserve_space(xdr, 4);
5502 	if (!p) {
5503 		status = nfserr_resource;
5504 		goto out;
5505 	}
5506 	*p = cpu_to_be32(eof);
5507 
5508 	cookie = offset + count;
5509 
5510 	wire_cookie = cpu_to_be64(cookie);
5511 	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &wire_cookie, 8);
5512 	tmp = cpu_to_be32(count);
5513 	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
5514 out:
5515 	if (listxattrs->lsxa_len)
5516 		kvfree(listxattrs->lsxa_buf);
5517 	return status;
5518 }
5519 
5520 static __be32
5521 nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
5522 			 union nfsd4_op_u *u)
5523 {
5524 	struct nfsd4_removexattr *removexattr = &u->removexattr;
5525 	struct xdr_stream *xdr = resp->xdr;
5526 
5527 	return nfsd4_encode_change_info4(xdr, &removexattr->rmxa_cinfo);
5528 }
5529 
5530 typedef __be32(*nfsd4_enc)(struct nfsd4_compoundres *, __be32, union nfsd4_op_u *u);
5531 
5532 /*
5533  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
5534  * since we don't need to filter out obsolete ops as this is
5535  * done in the decoding phase.
5536  */
5537 static const nfsd4_enc nfsd4_enc_ops[] = {
5538 	[OP_ACCESS]		= nfsd4_encode_access,
5539 	[OP_CLOSE]		= nfsd4_encode_close,
5540 	[OP_COMMIT]		= nfsd4_encode_commit,
5541 	[OP_CREATE]		= nfsd4_encode_create,
5542 	[OP_DELEGPURGE]		= nfsd4_encode_noop,
5543 	[OP_DELEGRETURN]	= nfsd4_encode_noop,
5544 	[OP_GETATTR]		= nfsd4_encode_getattr,
5545 	[OP_GETFH]		= nfsd4_encode_getfh,
5546 	[OP_LINK]		= nfsd4_encode_link,
5547 	[OP_LOCK]		= nfsd4_encode_lock,
5548 	[OP_LOCKT]		= nfsd4_encode_lockt,
5549 	[OP_LOCKU]		= nfsd4_encode_locku,
5550 	[OP_LOOKUP]		= nfsd4_encode_noop,
5551 	[OP_LOOKUPP]		= nfsd4_encode_noop,
5552 	[OP_NVERIFY]		= nfsd4_encode_noop,
5553 	[OP_OPEN]		= nfsd4_encode_open,
5554 	[OP_OPENATTR]		= nfsd4_encode_noop,
5555 	[OP_OPEN_CONFIRM]	= nfsd4_encode_open_confirm,
5556 	[OP_OPEN_DOWNGRADE]	= nfsd4_encode_open_downgrade,
5557 	[OP_PUTFH]		= nfsd4_encode_noop,
5558 	[OP_PUTPUBFH]		= nfsd4_encode_noop,
5559 	[OP_PUTROOTFH]		= nfsd4_encode_noop,
5560 	[OP_READ]		= nfsd4_encode_read,
5561 	[OP_READDIR]		= nfsd4_encode_readdir,
5562 	[OP_READLINK]		= nfsd4_encode_readlink,
5563 	[OP_REMOVE]		= nfsd4_encode_remove,
5564 	[OP_RENAME]		= nfsd4_encode_rename,
5565 	[OP_RENEW]		= nfsd4_encode_noop,
5566 	[OP_RESTOREFH]		= nfsd4_encode_noop,
5567 	[OP_SAVEFH]		= nfsd4_encode_noop,
5568 	[OP_SECINFO]		= nfsd4_encode_secinfo,
5569 	[OP_SETATTR]		= nfsd4_encode_setattr,
5570 	[OP_SETCLIENTID]	= nfsd4_encode_setclientid,
5571 	[OP_SETCLIENTID_CONFIRM] = nfsd4_encode_noop,
5572 	[OP_VERIFY]		= nfsd4_encode_noop,
5573 	[OP_WRITE]		= nfsd4_encode_write,
5574 	[OP_RELEASE_LOCKOWNER]	= nfsd4_encode_noop,
5575 
5576 	/* NFSv4.1 operations */
5577 	[OP_BACKCHANNEL_CTL]	= nfsd4_encode_noop,
5578 	[OP_BIND_CONN_TO_SESSION] = nfsd4_encode_bind_conn_to_session,
5579 	[OP_EXCHANGE_ID]	= nfsd4_encode_exchange_id,
5580 	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
5581 	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
5582 	[OP_FREE_STATEID]	= nfsd4_encode_noop,
5583 	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_noop,
5584 #ifdef CONFIG_NFSD_PNFS
5585 	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
5586 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5587 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_layoutcommit,
5588 	[OP_LAYOUTGET]		= nfsd4_encode_layoutget,
5589 	[OP_LAYOUTRETURN]	= nfsd4_encode_layoutreturn,
5590 #else
5591 	[OP_GETDEVICEINFO]	= nfsd4_encode_noop,
5592 	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
5593 	[OP_LAYOUTCOMMIT]	= nfsd4_encode_noop,
5594 	[OP_LAYOUTGET]		= nfsd4_encode_noop,
5595 	[OP_LAYOUTRETURN]	= nfsd4_encode_noop,
5596 #endif
5597 	[OP_SECINFO_NO_NAME]	= nfsd4_encode_secinfo_no_name,
5598 	[OP_SEQUENCE]		= nfsd4_encode_sequence,
5599 	[OP_SET_SSV]		= nfsd4_encode_noop,
5600 	[OP_TEST_STATEID]	= nfsd4_encode_test_stateid,
5601 	[OP_WANT_DELEGATION]	= nfsd4_encode_noop,
5602 	[OP_DESTROY_CLIENTID]	= nfsd4_encode_noop,
5603 	[OP_RECLAIM_COMPLETE]	= nfsd4_encode_noop,
5604 
5605 	/* NFSv4.2 operations */
5606 	[OP_ALLOCATE]		= nfsd4_encode_noop,
5607 	[OP_COPY]		= nfsd4_encode_copy,
5608 	[OP_COPY_NOTIFY]	= nfsd4_encode_copy_notify,
5609 	[OP_DEALLOCATE]		= nfsd4_encode_noop,
5610 	[OP_IO_ADVISE]		= nfsd4_encode_noop,
5611 	[OP_LAYOUTERROR]	= nfsd4_encode_noop,
5612 	[OP_LAYOUTSTATS]	= nfsd4_encode_noop,
5613 	[OP_OFFLOAD_CANCEL]	= nfsd4_encode_noop,
5614 	[OP_OFFLOAD_STATUS]	= nfsd4_encode_offload_status,
5615 	[OP_READ_PLUS]		= nfsd4_encode_read_plus,
5616 	[OP_SEEK]		= nfsd4_encode_seek,
5617 	[OP_WRITE_SAME]		= nfsd4_encode_noop,
5618 	[OP_CLONE]		= nfsd4_encode_noop,
5619 
5620 	/* RFC 8276 extended atributes operations */
5621 	[OP_GETXATTR]		= nfsd4_encode_getxattr,
5622 	[OP_SETXATTR]		= nfsd4_encode_setxattr,
5623 	[OP_LISTXATTRS]		= nfsd4_encode_listxattrs,
5624 	[OP_REMOVEXATTR]	= nfsd4_encode_removexattr,
5625 };
5626 
5627 /*
5628  * Calculate whether we still have space to encode repsize bytes.
5629  * There are two considerations:
5630  *     - For NFS versions >=4.1, the size of the reply must stay within
5631  *       session limits
5632  *     - For all NFS versions, we must stay within limited preallocated
5633  *       buffer space.
5634  *
5635  * This is called before the operation is processed, so can only provide
5636  * an upper estimate.  For some nonidempotent operations (such as
5637  * getattr), it's not necessarily a problem if that estimate is wrong,
5638  * as we can fail it after processing without significant side effects.
5639  */
5640 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
5641 {
5642 	struct xdr_buf *buf = &resp->rqstp->rq_res;
5643 	struct nfsd4_slot *slot = resp->cstate.slot;
5644 
5645 	if (buf->len + respsize <= buf->buflen)
5646 		return nfs_ok;
5647 	if (!nfsd4_has_session(&resp->cstate))
5648 		return nfserr_resource;
5649 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
5650 		WARN_ON_ONCE(1);
5651 		return nfserr_rep_too_big_to_cache;
5652 	}
5653 	return nfserr_rep_too_big;
5654 }
5655 
5656 void
5657 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
5658 {
5659 	struct xdr_stream *xdr = resp->xdr;
5660 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
5661 	struct svc_rqst *rqstp = resp->rqstp;
5662 	const struct nfsd4_operation *opdesc = op->opdesc;
5663 	int post_err_offset;
5664 	nfsd4_enc encoder;
5665 	__be32 *p;
5666 
5667 	p = xdr_reserve_space(xdr, 8);
5668 	if (!p)
5669 		goto release;
5670 	*p++ = cpu_to_be32(op->opnum);
5671 	post_err_offset = xdr->buf->len;
5672 
5673 	if (op->opnum == OP_ILLEGAL)
5674 		goto status;
5675 	if (op->status && opdesc &&
5676 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
5677 		goto status;
5678 	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
5679 	       !nfsd4_enc_ops[op->opnum]);
5680 	encoder = nfsd4_enc_ops[op->opnum];
5681 	op->status = encoder(resp, op->status, &op->u);
5682 	if (op->status)
5683 		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
5684 	xdr_commit_encode(xdr);
5685 
5686 	/* nfsd4_check_resp_size guarantees enough room for error status */
5687 	if (!op->status) {
5688 		int space_needed = 0;
5689 		if (!nfsd4_last_compound_op(rqstp))
5690 			space_needed = COMPOUND_ERR_SLACK_SPACE;
5691 		op->status = nfsd4_check_resp_size(resp, space_needed);
5692 	}
5693 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
5694 		struct nfsd4_slot *slot = resp->cstate.slot;
5695 
5696 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
5697 			op->status = nfserr_rep_too_big_to_cache;
5698 		else
5699 			op->status = nfserr_rep_too_big;
5700 	}
5701 	if (op->status == nfserr_resource ||
5702 	    op->status == nfserr_rep_too_big ||
5703 	    op->status == nfserr_rep_too_big_to_cache) {
5704 		/*
5705 		 * The operation may have already been encoded or
5706 		 * partially encoded.  No op returns anything additional
5707 		 * in the case of one of these three errors, so we can
5708 		 * just truncate back to after the status.  But it's a
5709 		 * bug if we had to do this on a non-idempotent op:
5710 		 */
5711 		warn_on_nonidempotent_op(op);
5712 		xdr_truncate_encode(xdr, post_err_offset);
5713 	}
5714 	if (so) {
5715 		int len = xdr->buf->len - post_err_offset;
5716 
5717 		so->so_replay.rp_status = op->status;
5718 		so->so_replay.rp_buflen = len;
5719 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
5720 						so->so_replay.rp_buf, len);
5721 	}
5722 status:
5723 	*p = op->status;
5724 release:
5725 	if (opdesc && opdesc->op_release)
5726 		opdesc->op_release(&op->u);
5727 
5728 	/*
5729 	 * Account for pages consumed while encoding this operation.
5730 	 * The xdr_stream primitives don't manage rq_next_page.
5731 	 */
5732 	rqstp->rq_next_page = xdr->page_ptr + 1;
5733 }
5734 
5735 /**
5736  * nfsd4_encode_replay - encode a result stored in the stateowner reply cache
5737  * @xdr: send buffer's XDR stream
5738  * @op: operation being replayed
5739  *
5740  * @op->replay->rp_buf contains the previously-sent already-encoded result.
5741  */
5742 void nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
5743 {
5744 	struct nfs4_replay *rp = op->replay;
5745 
5746 	trace_nfsd_stateowner_replay(op->opnum, rp);
5747 
5748 	if (xdr_stream_encode_u32(xdr, op->opnum) != XDR_UNIT)
5749 		return;
5750 	if (xdr_stream_encode_be32(xdr, rp->rp_status) != XDR_UNIT)
5751 		return;
5752 	xdr_stream_encode_opaque_fixed(xdr, rp->rp_buf, rp->rp_buflen);
5753 }
5754 
5755 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
5756 {
5757 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5758 
5759 	if (args->ops != args->iops) {
5760 		vfree(args->ops);
5761 		args->ops = args->iops;
5762 	}
5763 	while (args->to_free) {
5764 		struct svcxdr_tmpbuf *tb = args->to_free;
5765 		args->to_free = tb->next;
5766 		kfree(tb);
5767 	}
5768 }
5769 
5770 bool
5771 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5772 {
5773 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
5774 
5775 	/* svcxdr_tmp_alloc */
5776 	args->to_free = NULL;
5777 
5778 	args->xdr = xdr;
5779 	args->ops = args->iops;
5780 	args->rqstp = rqstp;
5781 
5782 	return nfsd4_decode_compound(args);
5783 }
5784 
5785 bool
5786 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
5787 {
5788 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
5789 	__be32 *p;
5790 
5791 	/*
5792 	 * Send buffer space for the following items is reserved
5793 	 * at the top of nfsd4_proc_compound().
5794 	 */
5795 	p = resp->statusp;
5796 
5797 	*p++ = resp->cstate.status;
5798 	*p++ = htonl(resp->taglen);
5799 	memcpy(p, resp->tag, resp->taglen);
5800 	p += XDR_QUADLEN(resp->taglen);
5801 	*p++ = htonl(resp->opcnt);
5802 
5803 	nfsd4_sequence_done(resp);
5804 	return true;
5805 }
5806