xref: /openbmc/linux/fs/nfsd/nfs4xdr.c (revision 74be2d3b)
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 
45 #include "idmap.h"
46 #include "acl.h"
47 #include "xdr4.h"
48 #include "vfs.h"
49 #include "state.h"
50 #include "cache.h"
51 #include "netns.h"
52 #include "pnfs.h"
53 #include "filecache.h"
54 
55 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
56 #include <linux/security.h>
57 #endif
58 
59 
60 #define NFSDDBG_FACILITY		NFSDDBG_XDR
61 
62 const u32 nfsd_suppattrs[3][3] = {
63 	{NFSD4_SUPPORTED_ATTRS_WORD0,
64 	 NFSD4_SUPPORTED_ATTRS_WORD1,
65 	 NFSD4_SUPPORTED_ATTRS_WORD2},
66 
67 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
68 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
69 	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
70 
71 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
72 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
73 	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
74 };
75 
76 /*
77  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
78  * directory in order to indicate to the client that a filesystem boundary is present
79  * We use a fixed fsid for a referral
80  */
81 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
82 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
83 
84 static __be32
85 check_filename(char *str, int len)
86 {
87 	int i;
88 
89 	if (len == 0)
90 		return nfserr_inval;
91 	if (isdotent(str, len))
92 		return nfserr_badname;
93 	for (i = 0; i < len; i++)
94 		if (str[i] == '/')
95 			return nfserr_badname;
96 	return 0;
97 }
98 
99 #define DECODE_HEAD				\
100 	__be32 *p;				\
101 	__be32 status
102 #define DECODE_TAIL				\
103 	status = 0;				\
104 out:						\
105 	return status;				\
106 xdr_error:					\
107 	dprintk("NFSD: xdr error (%s:%d)\n",	\
108 			__FILE__, __LINE__);	\
109 	status = nfserr_bad_xdr;		\
110 	goto out
111 
112 #define READMEM(x,nbytes) do {			\
113 	x = (char *)p;				\
114 	p += XDR_QUADLEN(nbytes);		\
115 } while (0)
116 #define SAVEMEM(x,nbytes) do {			\
117 	if (!(x = (p==argp->tmp || p == argp->tmpp) ? \
118  		savemem(argp, p, nbytes) :	\
119  		(char *)p)) {			\
120 		dprintk("NFSD: xdr error (%s:%d)\n", \
121 				__FILE__, __LINE__); \
122 		goto xdr_error;			\
123 		}				\
124 	p += XDR_QUADLEN(nbytes);		\
125 } while (0)
126 #define COPYMEM(x,nbytes) do {			\
127 	memcpy((x), p, nbytes);			\
128 	p += XDR_QUADLEN(nbytes);		\
129 } while (0)
130 
131 /* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
132 #define READ_BUF(nbytes)  do {			\
133 	if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) {	\
134 		p = argp->p;			\
135 		argp->p += XDR_QUADLEN(nbytes);	\
136 	} else if (!(p = read_buf(argp, nbytes))) { \
137 		dprintk("NFSD: xdr error (%s:%d)\n", \
138 				__FILE__, __LINE__); \
139 		goto xdr_error;			\
140 	}					\
141 } while (0)
142 
143 static void next_decode_page(struct nfsd4_compoundargs *argp)
144 {
145 	argp->p = page_address(argp->pagelist[0]);
146 	argp->pagelist++;
147 	if (argp->pagelen < PAGE_SIZE) {
148 		argp->end = argp->p + XDR_QUADLEN(argp->pagelen);
149 		argp->pagelen = 0;
150 	} else {
151 		argp->end = argp->p + (PAGE_SIZE>>2);
152 		argp->pagelen -= PAGE_SIZE;
153 	}
154 }
155 
156 static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
157 {
158 	/* We want more bytes than seem to be available.
159 	 * Maybe we need a new page, maybe we have just run out
160 	 */
161 	unsigned int avail = (char *)argp->end - (char *)argp->p;
162 	__be32 *p;
163 
164 	if (argp->pagelen == 0) {
165 		struct kvec *vec = &argp->rqstp->rq_arg.tail[0];
166 
167 		if (!argp->tail) {
168 			argp->tail = true;
169 			avail = vec->iov_len;
170 			argp->p = vec->iov_base;
171 			argp->end = vec->iov_base + avail;
172 		}
173 
174 		if (avail < nbytes)
175 			return NULL;
176 
177 		p = argp->p;
178 		argp->p += XDR_QUADLEN(nbytes);
179 		return p;
180 	}
181 
182 	if (avail + argp->pagelen < nbytes)
183 		return NULL;
184 	if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
185 		return NULL;
186 	/* ok, we can do it with the current plus the next page */
187 	if (nbytes <= sizeof(argp->tmp))
188 		p = argp->tmp;
189 	else {
190 		kfree(argp->tmpp);
191 		p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
192 		if (!p)
193 			return NULL;
194 
195 	}
196 	/*
197 	 * The following memcpy is safe because read_buf is always
198 	 * called with nbytes > avail, and the two cases above both
199 	 * guarantee p points to at least nbytes bytes.
200 	 */
201 	memcpy(p, argp->p, avail);
202 	next_decode_page(argp);
203 	memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
204 	argp->p += XDR_QUADLEN(nbytes - avail);
205 	return p;
206 }
207 
208 static unsigned int compoundargs_bytes_left(struct nfsd4_compoundargs *argp)
209 {
210 	unsigned int this = (char *)argp->end - (char *)argp->p;
211 
212 	return this + argp->pagelen;
213 }
214 
215 static int zero_clientid(clientid_t *clid)
216 {
217 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
218 }
219 
220 /**
221  * svcxdr_tmpalloc - allocate memory to be freed after compound processing
222  * @argp: NFSv4 compound argument structure
223  * @len: length of buffer to allocate
224  *
225  * Allocates a buffer of size @len to be freed when processing the compound
226  * operation described in @argp finishes.
227  */
228 static void *
229 svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
230 {
231 	struct svcxdr_tmpbuf *tb;
232 
233 	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
234 	if (!tb)
235 		return NULL;
236 	tb->next = argp->to_free;
237 	argp->to_free = tb;
238 	return tb->buf;
239 }
240 
241 /*
242  * For xdr strings that need to be passed to other kernel api's
243  * as null-terminated strings.
244  *
245  * Note null-terminating in place usually isn't safe since the
246  * buffer might end on a page boundary.
247  */
248 static char *
249 svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
250 {
251 	char *p = svcxdr_tmpalloc(argp, len + 1);
252 
253 	if (!p)
254 		return NULL;
255 	memcpy(p, buf, len);
256 	p[len] = '\0';
257 	return p;
258 }
259 
260 /**
261  * savemem - duplicate a chunk of memory for later processing
262  * @argp: NFSv4 compound argument structure to be freed with
263  * @p: pointer to be duplicated
264  * @nbytes: length to be duplicated
265  *
266  * Returns a pointer to a copy of @nbytes bytes of memory at @p
267  * that are preserved until processing of the NFSv4 compound
268  * operation described by @argp finishes.
269  */
270 static char *savemem(struct nfsd4_compoundargs *argp, __be32 *p, int nbytes)
271 {
272 	void *ret;
273 
274 	ret = svcxdr_tmpalloc(argp, nbytes);
275 	if (!ret)
276 		return NULL;
277 	memcpy(ret, p, nbytes);
278 	return ret;
279 }
280 
281 static __be32
282 nfsd4_decode_time(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
283 {
284 	DECODE_HEAD;
285 
286 	READ_BUF(12);
287 	p = xdr_decode_hyper(p, &tv->tv_sec);
288 	tv->tv_nsec = be32_to_cpup(p++);
289 	if (tv->tv_nsec >= (u32)1000000000)
290 		return nfserr_inval;
291 
292 	DECODE_TAIL;
293 }
294 
295 static __be32
296 nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
297 {
298 	u32 bmlen;
299 	DECODE_HEAD;
300 
301 	bmval[0] = 0;
302 	bmval[1] = 0;
303 	bmval[2] = 0;
304 
305 	READ_BUF(4);
306 	bmlen = be32_to_cpup(p++);
307 	if (bmlen > 1000)
308 		goto xdr_error;
309 
310 	READ_BUF(bmlen << 2);
311 	if (bmlen > 0)
312 		bmval[0] = be32_to_cpup(p++);
313 	if (bmlen > 1)
314 		bmval[1] = be32_to_cpup(p++);
315 	if (bmlen > 2)
316 		bmval[2] = be32_to_cpup(p++);
317 
318 	DECODE_TAIL;
319 }
320 
321 static __be32
322 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
323 		   struct iattr *iattr, struct nfs4_acl **acl,
324 		   struct xdr_netobj *label, int *umask)
325 {
326 	int expected_len, len = 0;
327 	u32 dummy32;
328 	char *buf;
329 
330 	DECODE_HEAD;
331 	iattr->ia_valid = 0;
332 	if ((status = nfsd4_decode_bitmap(argp, bmval)))
333 		return status;
334 
335 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
336 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
337 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
338 		if (nfsd_attrs_supported(argp->minorversion, bmval))
339 			return nfserr_inval;
340 		return nfserr_attrnotsupp;
341 	}
342 
343 	READ_BUF(4);
344 	expected_len = be32_to_cpup(p++);
345 
346 	if (bmval[0] & FATTR4_WORD0_SIZE) {
347 		READ_BUF(8);
348 		len += 8;
349 		p = xdr_decode_hyper(p, &iattr->ia_size);
350 		iattr->ia_valid |= ATTR_SIZE;
351 	}
352 	if (bmval[0] & FATTR4_WORD0_ACL) {
353 		u32 nace;
354 		struct nfs4_ace *ace;
355 
356 		READ_BUF(4); len += 4;
357 		nace = be32_to_cpup(p++);
358 
359 		if (nace > compoundargs_bytes_left(argp)/20)
360 			/*
361 			 * Even with 4-byte names there wouldn't be
362 			 * space for that many aces; something fishy is
363 			 * going on:
364 			 */
365 			return nfserr_fbig;
366 
367 		*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(nace));
368 		if (*acl == NULL)
369 			return nfserr_jukebox;
370 
371 		(*acl)->naces = nace;
372 		for (ace = (*acl)->aces; ace < (*acl)->aces + nace; ace++) {
373 			READ_BUF(16); len += 16;
374 			ace->type = be32_to_cpup(p++);
375 			ace->flag = be32_to_cpup(p++);
376 			ace->access_mask = be32_to_cpup(p++);
377 			dummy32 = be32_to_cpup(p++);
378 			READ_BUF(dummy32);
379 			len += XDR_QUADLEN(dummy32) << 2;
380 			READMEM(buf, dummy32);
381 			ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
382 			status = nfs_ok;
383 			if (ace->whotype != NFS4_ACL_WHO_NAMED)
384 				;
385 			else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
386 				status = nfsd_map_name_to_gid(argp->rqstp,
387 						buf, dummy32, &ace->who_gid);
388 			else
389 				status = nfsd_map_name_to_uid(argp->rqstp,
390 						buf, dummy32, &ace->who_uid);
391 			if (status)
392 				return status;
393 		}
394 	} else
395 		*acl = NULL;
396 	if (bmval[1] & FATTR4_WORD1_MODE) {
397 		READ_BUF(4);
398 		len += 4;
399 		iattr->ia_mode = be32_to_cpup(p++);
400 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
401 		iattr->ia_valid |= ATTR_MODE;
402 	}
403 	if (bmval[1] & FATTR4_WORD1_OWNER) {
404 		READ_BUF(4);
405 		len += 4;
406 		dummy32 = be32_to_cpup(p++);
407 		READ_BUF(dummy32);
408 		len += (XDR_QUADLEN(dummy32) << 2);
409 		READMEM(buf, dummy32);
410 		if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid)))
411 			return status;
412 		iattr->ia_valid |= ATTR_UID;
413 	}
414 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
415 		READ_BUF(4);
416 		len += 4;
417 		dummy32 = be32_to_cpup(p++);
418 		READ_BUF(dummy32);
419 		len += (XDR_QUADLEN(dummy32) << 2);
420 		READMEM(buf, dummy32);
421 		if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid)))
422 			return status;
423 		iattr->ia_valid |= ATTR_GID;
424 	}
425 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
426 		READ_BUF(4);
427 		len += 4;
428 		dummy32 = be32_to_cpup(p++);
429 		switch (dummy32) {
430 		case NFS4_SET_TO_CLIENT_TIME:
431 			len += 12;
432 			status = nfsd4_decode_time(argp, &iattr->ia_atime);
433 			if (status)
434 				return status;
435 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
436 			break;
437 		case NFS4_SET_TO_SERVER_TIME:
438 			iattr->ia_valid |= ATTR_ATIME;
439 			break;
440 		default:
441 			goto xdr_error;
442 		}
443 	}
444 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
445 		READ_BUF(4);
446 		len += 4;
447 		dummy32 = be32_to_cpup(p++);
448 		switch (dummy32) {
449 		case NFS4_SET_TO_CLIENT_TIME:
450 			len += 12;
451 			status = nfsd4_decode_time(argp, &iattr->ia_mtime);
452 			if (status)
453 				return status;
454 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
455 			break;
456 		case NFS4_SET_TO_SERVER_TIME:
457 			iattr->ia_valid |= ATTR_MTIME;
458 			break;
459 		default:
460 			goto xdr_error;
461 		}
462 	}
463 
464 	label->len = 0;
465 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
466 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
467 		READ_BUF(4);
468 		len += 4;
469 		dummy32 = be32_to_cpup(p++); /* lfs: we don't use it */
470 		READ_BUF(4);
471 		len += 4;
472 		dummy32 = be32_to_cpup(p++); /* pi: we don't use it either */
473 		READ_BUF(4);
474 		len += 4;
475 		dummy32 = be32_to_cpup(p++);
476 		READ_BUF(dummy32);
477 		if (dummy32 > NFS4_MAXLABELLEN)
478 			return nfserr_badlabel;
479 		len += (XDR_QUADLEN(dummy32) << 2);
480 		READMEM(buf, dummy32);
481 		label->len = dummy32;
482 		label->data = svcxdr_dupstr(argp, buf, dummy32);
483 		if (!label->data)
484 			return nfserr_jukebox;
485 	}
486 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
487 		if (!umask)
488 			goto xdr_error;
489 		READ_BUF(8);
490 		len += 8;
491 		dummy32 = be32_to_cpup(p++);
492 		iattr->ia_mode = dummy32 & (S_IFMT | S_IALLUGO);
493 		dummy32 = be32_to_cpup(p++);
494 		*umask = dummy32 & S_IRWXUGO;
495 		iattr->ia_valid |= ATTR_MODE;
496 	}
497 	if (len != expected_len)
498 		goto xdr_error;
499 
500 	DECODE_TAIL;
501 }
502 
503 static __be32
504 nfsd4_decode_stateid(struct nfsd4_compoundargs *argp, stateid_t *sid)
505 {
506 	DECODE_HEAD;
507 
508 	READ_BUF(sizeof(stateid_t));
509 	sid->si_generation = be32_to_cpup(p++);
510 	COPYMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
511 
512 	DECODE_TAIL;
513 }
514 
515 static __be32
516 nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access)
517 {
518 	DECODE_HEAD;
519 
520 	READ_BUF(4);
521 	access->ac_req_access = be32_to_cpup(p++);
522 
523 	DECODE_TAIL;
524 }
525 
526 static __be32 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
527 {
528 	DECODE_HEAD;
529 	struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
530 	u32 dummy, uid, gid;
531 	char *machine_name;
532 	int i;
533 	int nr_secflavs;
534 
535 	/* callback_sec_params4 */
536 	READ_BUF(4);
537 	nr_secflavs = be32_to_cpup(p++);
538 	if (nr_secflavs)
539 		cbs->flavor = (u32)(-1);
540 	else
541 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
542 		cbs->flavor = 0;
543 	for (i = 0; i < nr_secflavs; ++i) {
544 		READ_BUF(4);
545 		dummy = be32_to_cpup(p++);
546 		switch (dummy) {
547 		case RPC_AUTH_NULL:
548 			/* Nothing to read */
549 			if (cbs->flavor == (u32)(-1))
550 				cbs->flavor = RPC_AUTH_NULL;
551 			break;
552 		case RPC_AUTH_UNIX:
553 			READ_BUF(8);
554 			/* stamp */
555 			dummy = be32_to_cpup(p++);
556 
557 			/* machine name */
558 			dummy = be32_to_cpup(p++);
559 			READ_BUF(dummy);
560 			SAVEMEM(machine_name, dummy);
561 
562 			/* uid, gid */
563 			READ_BUF(8);
564 			uid = be32_to_cpup(p++);
565 			gid = be32_to_cpup(p++);
566 
567 			/* more gids */
568 			READ_BUF(4);
569 			dummy = be32_to_cpup(p++);
570 			READ_BUF(dummy * 4);
571 			if (cbs->flavor == (u32)(-1)) {
572 				kuid_t kuid = make_kuid(userns, uid);
573 				kgid_t kgid = make_kgid(userns, gid);
574 				if (uid_valid(kuid) && gid_valid(kgid)) {
575 					cbs->uid = kuid;
576 					cbs->gid = kgid;
577 					cbs->flavor = RPC_AUTH_UNIX;
578 				} else {
579 					dprintk("RPC_AUTH_UNIX with invalid"
580 						"uid or gid ignoring!\n");
581 				}
582 			}
583 			break;
584 		case RPC_AUTH_GSS:
585 			dprintk("RPC_AUTH_GSS callback secflavor "
586 				"not supported!\n");
587 			READ_BUF(8);
588 			/* gcbp_service */
589 			dummy = be32_to_cpup(p++);
590 			/* gcbp_handle_from_server */
591 			dummy = be32_to_cpup(p++);
592 			READ_BUF(dummy);
593 			p += XDR_QUADLEN(dummy);
594 			/* gcbp_handle_from_client */
595 			READ_BUF(4);
596 			dummy = be32_to_cpup(p++);
597 			READ_BUF(dummy);
598 			break;
599 		default:
600 			dprintk("Illegal callback secflavor\n");
601 			return nfserr_inval;
602 		}
603 	}
604 	DECODE_TAIL;
605 }
606 
607 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
608 {
609 	DECODE_HEAD;
610 
611 	READ_BUF(4);
612 	bc->bc_cb_program = be32_to_cpup(p++);
613 	nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
614 
615 	DECODE_TAIL;
616 }
617 
618 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
619 {
620 	DECODE_HEAD;
621 
622 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 8);
623 	COPYMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
624 	bcts->dir = be32_to_cpup(p++);
625 	/* XXX: skipping ctsa_use_conn_in_rdma_mode.  Perhaps Tom Tucker
626 	 * could help us figure out we should be using it. */
627 	DECODE_TAIL;
628 }
629 
630 static __be32
631 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
632 {
633 	DECODE_HEAD;
634 
635 	READ_BUF(4);
636 	close->cl_seqid = be32_to_cpup(p++);
637 	return nfsd4_decode_stateid(argp, &close->cl_stateid);
638 
639 	DECODE_TAIL;
640 }
641 
642 
643 static __be32
644 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
645 {
646 	DECODE_HEAD;
647 
648 	READ_BUF(12);
649 	p = xdr_decode_hyper(p, &commit->co_offset);
650 	commit->co_count = be32_to_cpup(p++);
651 
652 	DECODE_TAIL;
653 }
654 
655 static __be32
656 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
657 {
658 	DECODE_HEAD;
659 
660 	READ_BUF(4);
661 	create->cr_type = be32_to_cpup(p++);
662 	switch (create->cr_type) {
663 	case NF4LNK:
664 		READ_BUF(4);
665 		create->cr_datalen = be32_to_cpup(p++);
666 		READ_BUF(create->cr_datalen);
667 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
668 		if (!create->cr_data)
669 			return nfserr_jukebox;
670 		break;
671 	case NF4BLK:
672 	case NF4CHR:
673 		READ_BUF(8);
674 		create->cr_specdata1 = be32_to_cpup(p++);
675 		create->cr_specdata2 = be32_to_cpup(p++);
676 		break;
677 	case NF4SOCK:
678 	case NF4FIFO:
679 	case NF4DIR:
680 	default:
681 		break;
682 	}
683 
684 	READ_BUF(4);
685 	create->cr_namelen = be32_to_cpup(p++);
686 	READ_BUF(create->cr_namelen);
687 	SAVEMEM(create->cr_name, create->cr_namelen);
688 	if ((status = check_filename(create->cr_name, create->cr_namelen)))
689 		return status;
690 
691 	status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
692 				    &create->cr_acl, &create->cr_label,
693 				    &create->cr_umask);
694 	if (status)
695 		goto out;
696 
697 	DECODE_TAIL;
698 }
699 
700 static inline __be32
701 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
702 {
703 	return nfsd4_decode_stateid(argp, &dr->dr_stateid);
704 }
705 
706 static inline __be32
707 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
708 {
709 	return nfsd4_decode_bitmap(argp, getattr->ga_bmval);
710 }
711 
712 static __be32
713 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
714 {
715 	DECODE_HEAD;
716 
717 	READ_BUF(4);
718 	link->li_namelen = be32_to_cpup(p++);
719 	READ_BUF(link->li_namelen);
720 	SAVEMEM(link->li_name, link->li_namelen);
721 	if ((status = check_filename(link->li_name, link->li_namelen)))
722 		return status;
723 
724 	DECODE_TAIL;
725 }
726 
727 static __be32
728 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
729 {
730 	DECODE_HEAD;
731 
732 	/*
733 	* type, reclaim(boolean), offset, length, new_lock_owner(boolean)
734 	*/
735 	READ_BUF(28);
736 	lock->lk_type = be32_to_cpup(p++);
737 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
738 		goto xdr_error;
739 	lock->lk_reclaim = be32_to_cpup(p++);
740 	p = xdr_decode_hyper(p, &lock->lk_offset);
741 	p = xdr_decode_hyper(p, &lock->lk_length);
742 	lock->lk_is_new = be32_to_cpup(p++);
743 
744 	if (lock->lk_is_new) {
745 		READ_BUF(4);
746 		lock->lk_new_open_seqid = be32_to_cpup(p++);
747 		status = nfsd4_decode_stateid(argp, &lock->lk_new_open_stateid);
748 		if (status)
749 			return status;
750 		READ_BUF(8 + sizeof(clientid_t));
751 		lock->lk_new_lock_seqid = be32_to_cpup(p++);
752 		COPYMEM(&lock->lk_new_clientid, sizeof(clientid_t));
753 		lock->lk_new_owner.len = be32_to_cpup(p++);
754 		READ_BUF(lock->lk_new_owner.len);
755 		READMEM(lock->lk_new_owner.data, lock->lk_new_owner.len);
756 	} else {
757 		status = nfsd4_decode_stateid(argp, &lock->lk_old_lock_stateid);
758 		if (status)
759 			return status;
760 		READ_BUF(4);
761 		lock->lk_old_lock_seqid = be32_to_cpup(p++);
762 	}
763 
764 	DECODE_TAIL;
765 }
766 
767 static __be32
768 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
769 {
770 	DECODE_HEAD;
771 
772 	READ_BUF(32);
773 	lockt->lt_type = be32_to_cpup(p++);
774 	if((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
775 		goto xdr_error;
776 	p = xdr_decode_hyper(p, &lockt->lt_offset);
777 	p = xdr_decode_hyper(p, &lockt->lt_length);
778 	COPYMEM(&lockt->lt_clientid, 8);
779 	lockt->lt_owner.len = be32_to_cpup(p++);
780 	READ_BUF(lockt->lt_owner.len);
781 	READMEM(lockt->lt_owner.data, lockt->lt_owner.len);
782 
783 	DECODE_TAIL;
784 }
785 
786 static __be32
787 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
788 {
789 	DECODE_HEAD;
790 
791 	READ_BUF(8);
792 	locku->lu_type = be32_to_cpup(p++);
793 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
794 		goto xdr_error;
795 	locku->lu_seqid = be32_to_cpup(p++);
796 	status = nfsd4_decode_stateid(argp, &locku->lu_stateid);
797 	if (status)
798 		return status;
799 	READ_BUF(16);
800 	p = xdr_decode_hyper(p, &locku->lu_offset);
801 	p = xdr_decode_hyper(p, &locku->lu_length);
802 
803 	DECODE_TAIL;
804 }
805 
806 static __be32
807 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
808 {
809 	DECODE_HEAD;
810 
811 	READ_BUF(4);
812 	lookup->lo_len = be32_to_cpup(p++);
813 	READ_BUF(lookup->lo_len);
814 	SAVEMEM(lookup->lo_name, lookup->lo_len);
815 	if ((status = check_filename(lookup->lo_name, lookup->lo_len)))
816 		return status;
817 
818 	DECODE_TAIL;
819 }
820 
821 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
822 {
823 	__be32 *p;
824 	u32 w;
825 
826 	READ_BUF(4);
827 	w = be32_to_cpup(p++);
828 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
829 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
830 	if (deleg_when)
831 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
832 
833 	switch (w & NFS4_SHARE_ACCESS_MASK) {
834 	case NFS4_SHARE_ACCESS_READ:
835 	case NFS4_SHARE_ACCESS_WRITE:
836 	case NFS4_SHARE_ACCESS_BOTH:
837 		break;
838 	default:
839 		return nfserr_bad_xdr;
840 	}
841 	w &= ~NFS4_SHARE_ACCESS_MASK;
842 	if (!w)
843 		return nfs_ok;
844 	if (!argp->minorversion)
845 		return nfserr_bad_xdr;
846 	switch (w & NFS4_SHARE_WANT_MASK) {
847 	case NFS4_SHARE_WANT_NO_PREFERENCE:
848 	case NFS4_SHARE_WANT_READ_DELEG:
849 	case NFS4_SHARE_WANT_WRITE_DELEG:
850 	case NFS4_SHARE_WANT_ANY_DELEG:
851 	case NFS4_SHARE_WANT_NO_DELEG:
852 	case NFS4_SHARE_WANT_CANCEL:
853 		break;
854 	default:
855 		return nfserr_bad_xdr;
856 	}
857 	w &= ~NFS4_SHARE_WANT_MASK;
858 	if (!w)
859 		return nfs_ok;
860 
861 	if (!deleg_when)	/* open_downgrade */
862 		return nfserr_inval;
863 	switch (w) {
864 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
865 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
866 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
867 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
868 		return nfs_ok;
869 	}
870 xdr_error:
871 	return nfserr_bad_xdr;
872 }
873 
874 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
875 {
876 	__be32 *p;
877 
878 	READ_BUF(4);
879 	*x = be32_to_cpup(p++);
880 	/* Note: unlinke access bits, deny bits may be zero. */
881 	if (*x & ~NFS4_SHARE_DENY_BOTH)
882 		return nfserr_bad_xdr;
883 	return nfs_ok;
884 xdr_error:
885 	return nfserr_bad_xdr;
886 }
887 
888 static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
889 {
890 	__be32 *p;
891 
892 	READ_BUF(4);
893 	o->len = be32_to_cpup(p++);
894 
895 	if (o->len == 0 || o->len > NFS4_OPAQUE_LIMIT)
896 		return nfserr_bad_xdr;
897 
898 	READ_BUF(o->len);
899 	SAVEMEM(o->data, o->len);
900 	return nfs_ok;
901 xdr_error:
902 	return nfserr_bad_xdr;
903 }
904 
905 static __be32
906 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
907 {
908 	DECODE_HEAD;
909 	u32 dummy;
910 
911 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
912 	open->op_iattr.ia_valid = 0;
913 	open->op_openowner = NULL;
914 
915 	open->op_xdr_error = 0;
916 	/* seqid, share_access, share_deny, clientid, ownerlen */
917 	READ_BUF(4);
918 	open->op_seqid = be32_to_cpup(p++);
919 	/* decode, yet ignore deleg_when until supported */
920 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
921 					   &open->op_deleg_want, &dummy);
922 	if (status)
923 		goto xdr_error;
924 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
925 	if (status)
926 		goto xdr_error;
927 	READ_BUF(sizeof(clientid_t));
928 	COPYMEM(&open->op_clientid, sizeof(clientid_t));
929 	status = nfsd4_decode_opaque(argp, &open->op_owner);
930 	if (status)
931 		goto xdr_error;
932 	READ_BUF(4);
933 	open->op_create = be32_to_cpup(p++);
934 	switch (open->op_create) {
935 	case NFS4_OPEN_NOCREATE:
936 		break;
937 	case NFS4_OPEN_CREATE:
938 		READ_BUF(4);
939 		open->op_createmode = be32_to_cpup(p++);
940 		switch (open->op_createmode) {
941 		case NFS4_CREATE_UNCHECKED:
942 		case NFS4_CREATE_GUARDED:
943 			status = nfsd4_decode_fattr(argp, open->op_bmval,
944 				&open->op_iattr, &open->op_acl, &open->op_label,
945 				&open->op_umask);
946 			if (status)
947 				goto out;
948 			break;
949 		case NFS4_CREATE_EXCLUSIVE:
950 			READ_BUF(NFS4_VERIFIER_SIZE);
951 			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
952 			break;
953 		case NFS4_CREATE_EXCLUSIVE4_1:
954 			if (argp->minorversion < 1)
955 				goto xdr_error;
956 			READ_BUF(NFS4_VERIFIER_SIZE);
957 			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
958 			status = nfsd4_decode_fattr(argp, open->op_bmval,
959 				&open->op_iattr, &open->op_acl, &open->op_label,
960 				&open->op_umask);
961 			if (status)
962 				goto out;
963 			break;
964 		default:
965 			goto xdr_error;
966 		}
967 		break;
968 	default:
969 		goto xdr_error;
970 	}
971 
972 	/* open_claim */
973 	READ_BUF(4);
974 	open->op_claim_type = be32_to_cpup(p++);
975 	switch (open->op_claim_type) {
976 	case NFS4_OPEN_CLAIM_NULL:
977 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
978 		READ_BUF(4);
979 		open->op_fname.len = be32_to_cpup(p++);
980 		READ_BUF(open->op_fname.len);
981 		SAVEMEM(open->op_fname.data, open->op_fname.len);
982 		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
983 			return status;
984 		break;
985 	case NFS4_OPEN_CLAIM_PREVIOUS:
986 		READ_BUF(4);
987 		open->op_delegate_type = be32_to_cpup(p++);
988 		break;
989 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
990 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
991 		if (status)
992 			return status;
993 		READ_BUF(4);
994 		open->op_fname.len = be32_to_cpup(p++);
995 		READ_BUF(open->op_fname.len);
996 		SAVEMEM(open->op_fname.data, open->op_fname.len);
997 		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
998 			return status;
999 		break;
1000 	case NFS4_OPEN_CLAIM_FH:
1001 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
1002 		if (argp->minorversion < 1)
1003 			goto xdr_error;
1004 		/* void */
1005 		break;
1006 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1007 		if (argp->minorversion < 1)
1008 			goto xdr_error;
1009 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
1010 		if (status)
1011 			return status;
1012 		break;
1013 	default:
1014 		goto xdr_error;
1015 	}
1016 
1017 	DECODE_TAIL;
1018 }
1019 
1020 static __be32
1021 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
1022 {
1023 	DECODE_HEAD;
1024 
1025 	if (argp->minorversion >= 1)
1026 		return nfserr_notsupp;
1027 
1028 	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
1029 	if (status)
1030 		return status;
1031 	READ_BUF(4);
1032 	open_conf->oc_seqid = be32_to_cpup(p++);
1033 
1034 	DECODE_TAIL;
1035 }
1036 
1037 static __be32
1038 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
1039 {
1040 	DECODE_HEAD;
1041 
1042 	status = nfsd4_decode_stateid(argp, &open_down->od_stateid);
1043 	if (status)
1044 		return status;
1045 	READ_BUF(4);
1046 	open_down->od_seqid = be32_to_cpup(p++);
1047 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1048 					   &open_down->od_deleg_want, NULL);
1049 	if (status)
1050 		return status;
1051 	status = nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1052 	if (status)
1053 		return status;
1054 	DECODE_TAIL;
1055 }
1056 
1057 static __be32
1058 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
1059 {
1060 	DECODE_HEAD;
1061 
1062 	READ_BUF(4);
1063 	putfh->pf_fhlen = be32_to_cpup(p++);
1064 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1065 		goto xdr_error;
1066 	READ_BUF(putfh->pf_fhlen);
1067 	SAVEMEM(putfh->pf_fhval, putfh->pf_fhlen);
1068 
1069 	DECODE_TAIL;
1070 }
1071 
1072 static __be32
1073 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
1074 {
1075 	if (argp->minorversion == 0)
1076 		return nfs_ok;
1077 	return nfserr_notsupp;
1078 }
1079 
1080 static __be32
1081 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
1082 {
1083 	DECODE_HEAD;
1084 
1085 	status = nfsd4_decode_stateid(argp, &read->rd_stateid);
1086 	if (status)
1087 		return status;
1088 	READ_BUF(12);
1089 	p = xdr_decode_hyper(p, &read->rd_offset);
1090 	read->rd_length = be32_to_cpup(p++);
1091 
1092 	DECODE_TAIL;
1093 }
1094 
1095 static __be32
1096 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
1097 {
1098 	DECODE_HEAD;
1099 
1100 	READ_BUF(24);
1101 	p = xdr_decode_hyper(p, &readdir->rd_cookie);
1102 	COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
1103 	readdir->rd_dircount = be32_to_cpup(p++);
1104 	readdir->rd_maxcount = be32_to_cpup(p++);
1105 	if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
1106 		goto out;
1107 
1108 	DECODE_TAIL;
1109 }
1110 
1111 static __be32
1112 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
1113 {
1114 	DECODE_HEAD;
1115 
1116 	READ_BUF(4);
1117 	remove->rm_namelen = be32_to_cpup(p++);
1118 	READ_BUF(remove->rm_namelen);
1119 	SAVEMEM(remove->rm_name, remove->rm_namelen);
1120 	if ((status = check_filename(remove->rm_name, remove->rm_namelen)))
1121 		return status;
1122 
1123 	DECODE_TAIL;
1124 }
1125 
1126 static __be32
1127 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
1128 {
1129 	DECODE_HEAD;
1130 
1131 	READ_BUF(4);
1132 	rename->rn_snamelen = be32_to_cpup(p++);
1133 	READ_BUF(rename->rn_snamelen);
1134 	SAVEMEM(rename->rn_sname, rename->rn_snamelen);
1135 	READ_BUF(4);
1136 	rename->rn_tnamelen = be32_to_cpup(p++);
1137 	READ_BUF(rename->rn_tnamelen);
1138 	SAVEMEM(rename->rn_tname, rename->rn_tnamelen);
1139 	if ((status = check_filename(rename->rn_sname, rename->rn_snamelen)))
1140 		return status;
1141 	if ((status = check_filename(rename->rn_tname, rename->rn_tnamelen)))
1142 		return status;
1143 
1144 	DECODE_TAIL;
1145 }
1146 
1147 static __be32
1148 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
1149 {
1150 	DECODE_HEAD;
1151 
1152 	if (argp->minorversion >= 1)
1153 		return nfserr_notsupp;
1154 
1155 	READ_BUF(sizeof(clientid_t));
1156 	COPYMEM(clientid, sizeof(clientid_t));
1157 
1158 	DECODE_TAIL;
1159 }
1160 
1161 static __be32
1162 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1163 		     struct nfsd4_secinfo *secinfo)
1164 {
1165 	DECODE_HEAD;
1166 
1167 	READ_BUF(4);
1168 	secinfo->si_namelen = be32_to_cpup(p++);
1169 	READ_BUF(secinfo->si_namelen);
1170 	SAVEMEM(secinfo->si_name, secinfo->si_namelen);
1171 	status = check_filename(secinfo->si_name, secinfo->si_namelen);
1172 	if (status)
1173 		return status;
1174 	DECODE_TAIL;
1175 }
1176 
1177 static __be32
1178 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1179 		     struct nfsd4_secinfo_no_name *sin)
1180 {
1181 	DECODE_HEAD;
1182 
1183 	READ_BUF(4);
1184 	sin->sin_style = be32_to_cpup(p++);
1185 	DECODE_TAIL;
1186 }
1187 
1188 static __be32
1189 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
1190 {
1191 	__be32 status;
1192 
1193 	status = nfsd4_decode_stateid(argp, &setattr->sa_stateid);
1194 	if (status)
1195 		return status;
1196 	return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
1197 				  &setattr->sa_acl, &setattr->sa_label, NULL);
1198 }
1199 
1200 static __be32
1201 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
1202 {
1203 	DECODE_HEAD;
1204 
1205 	if (argp->minorversion >= 1)
1206 		return nfserr_notsupp;
1207 
1208 	READ_BUF(NFS4_VERIFIER_SIZE);
1209 	COPYMEM(setclientid->se_verf.data, NFS4_VERIFIER_SIZE);
1210 
1211 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1212 	if (status)
1213 		return nfserr_bad_xdr;
1214 	READ_BUF(8);
1215 	setclientid->se_callback_prog = be32_to_cpup(p++);
1216 	setclientid->se_callback_netid_len = be32_to_cpup(p++);
1217 	READ_BUF(setclientid->se_callback_netid_len);
1218 	SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len);
1219 	READ_BUF(4);
1220 	setclientid->se_callback_addr_len = be32_to_cpup(p++);
1221 
1222 	READ_BUF(setclientid->se_callback_addr_len);
1223 	SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len);
1224 	READ_BUF(4);
1225 	setclientid->se_callback_ident = be32_to_cpup(p++);
1226 
1227 	DECODE_TAIL;
1228 }
1229 
1230 static __be32
1231 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1232 {
1233 	DECODE_HEAD;
1234 
1235 	if (argp->minorversion >= 1)
1236 		return nfserr_notsupp;
1237 
1238 	READ_BUF(8 + NFS4_VERIFIER_SIZE);
1239 	COPYMEM(&scd_c->sc_clientid, 8);
1240 	COPYMEM(&scd_c->sc_confirm, NFS4_VERIFIER_SIZE);
1241 
1242 	DECODE_TAIL;
1243 }
1244 
1245 /* Also used for NVERIFY */
1246 static __be32
1247 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1248 {
1249 	DECODE_HEAD;
1250 
1251 	if ((status = nfsd4_decode_bitmap(argp, verify->ve_bmval)))
1252 		goto out;
1253 
1254 	/* For convenience's sake, we compare raw xdr'd attributes in
1255 	 * nfsd4_proc_verify */
1256 
1257 	READ_BUF(4);
1258 	verify->ve_attrlen = be32_to_cpup(p++);
1259 	READ_BUF(verify->ve_attrlen);
1260 	SAVEMEM(verify->ve_attrval, verify->ve_attrlen);
1261 
1262 	DECODE_TAIL;
1263 }
1264 
1265 static __be32
1266 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1267 {
1268 	int avail;
1269 	int len;
1270 	DECODE_HEAD;
1271 
1272 	status = nfsd4_decode_stateid(argp, &write->wr_stateid);
1273 	if (status)
1274 		return status;
1275 	READ_BUF(16);
1276 	p = xdr_decode_hyper(p, &write->wr_offset);
1277 	write->wr_stable_how = be32_to_cpup(p++);
1278 	if (write->wr_stable_how > NFS_FILE_SYNC)
1279 		goto xdr_error;
1280 	write->wr_buflen = be32_to_cpup(p++);
1281 
1282 	/* Sorry .. no magic macros for this.. *
1283 	 * READ_BUF(write->wr_buflen);
1284 	 * SAVEMEM(write->wr_buf, write->wr_buflen);
1285 	 */
1286 	avail = (char*)argp->end - (char*)argp->p;
1287 	if (avail + argp->pagelen < write->wr_buflen) {
1288 		dprintk("NFSD: xdr error (%s:%d)\n",
1289 				__FILE__, __LINE__);
1290 		goto xdr_error;
1291 	}
1292 	write->wr_head.iov_base = p;
1293 	write->wr_head.iov_len = avail;
1294 	write->wr_pagelist = argp->pagelist;
1295 
1296 	len = XDR_QUADLEN(write->wr_buflen) << 2;
1297 	if (len >= avail) {
1298 		int pages;
1299 
1300 		len -= avail;
1301 
1302 		pages = len >> PAGE_SHIFT;
1303 		argp->pagelist += pages;
1304 		argp->pagelen -= pages * PAGE_SIZE;
1305 		len -= pages * PAGE_SIZE;
1306 
1307 		next_decode_page(argp);
1308 	}
1309 	argp->p += XDR_QUADLEN(len);
1310 
1311 	DECODE_TAIL;
1312 }
1313 
1314 static __be32
1315 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1316 {
1317 	DECODE_HEAD;
1318 
1319 	if (argp->minorversion >= 1)
1320 		return nfserr_notsupp;
1321 
1322 	READ_BUF(12);
1323 	COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
1324 	rlockowner->rl_owner.len = be32_to_cpup(p++);
1325 	READ_BUF(rlockowner->rl_owner.len);
1326 	READMEM(rlockowner->rl_owner.data, rlockowner->rl_owner.len);
1327 
1328 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1329 		return nfserr_inval;
1330 	DECODE_TAIL;
1331 }
1332 
1333 static __be32
1334 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1335 			 struct nfsd4_exchange_id *exid)
1336 {
1337 	int dummy, tmp;
1338 	DECODE_HEAD;
1339 
1340 	READ_BUF(NFS4_VERIFIER_SIZE);
1341 	COPYMEM(exid->verifier.data, NFS4_VERIFIER_SIZE);
1342 
1343 	status = nfsd4_decode_opaque(argp, &exid->clname);
1344 	if (status)
1345 		return nfserr_bad_xdr;
1346 
1347 	READ_BUF(4);
1348 	exid->flags = be32_to_cpup(p++);
1349 
1350 	/* Ignore state_protect4_a */
1351 	READ_BUF(4);
1352 	exid->spa_how = be32_to_cpup(p++);
1353 	switch (exid->spa_how) {
1354 	case SP4_NONE:
1355 		break;
1356 	case SP4_MACH_CRED:
1357 		/* spo_must_enforce */
1358 		status = nfsd4_decode_bitmap(argp,
1359 					exid->spo_must_enforce);
1360 		if (status)
1361 			goto out;
1362 		/* spo_must_allow */
1363 		status = nfsd4_decode_bitmap(argp, exid->spo_must_allow);
1364 		if (status)
1365 			goto out;
1366 		break;
1367 	case SP4_SSV:
1368 		/* ssp_ops */
1369 		READ_BUF(4);
1370 		dummy = be32_to_cpup(p++);
1371 		READ_BUF(dummy * 4);
1372 		p += dummy;
1373 
1374 		READ_BUF(4);
1375 		dummy = be32_to_cpup(p++);
1376 		READ_BUF(dummy * 4);
1377 		p += dummy;
1378 
1379 		/* ssp_hash_algs<> */
1380 		READ_BUF(4);
1381 		tmp = be32_to_cpup(p++);
1382 		while (tmp--) {
1383 			READ_BUF(4);
1384 			dummy = be32_to_cpup(p++);
1385 			READ_BUF(dummy);
1386 			p += XDR_QUADLEN(dummy);
1387 		}
1388 
1389 		/* ssp_encr_algs<> */
1390 		READ_BUF(4);
1391 		tmp = be32_to_cpup(p++);
1392 		while (tmp--) {
1393 			READ_BUF(4);
1394 			dummy = be32_to_cpup(p++);
1395 			READ_BUF(dummy);
1396 			p += XDR_QUADLEN(dummy);
1397 		}
1398 
1399 		/* ignore ssp_window and ssp_num_gss_handles: */
1400 		READ_BUF(8);
1401 		break;
1402 	default:
1403 		goto xdr_error;
1404 	}
1405 
1406 	READ_BUF(4);    /* nfs_impl_id4 array length */
1407 	dummy = be32_to_cpup(p++);
1408 
1409 	if (dummy > 1)
1410 		goto xdr_error;
1411 
1412 	if (dummy == 1) {
1413 		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
1414 		if (status)
1415 			goto xdr_error;
1416 
1417 		/* nii_name */
1418 		status = nfsd4_decode_opaque(argp, &exid->nii_name);
1419 		if (status)
1420 			goto xdr_error;
1421 
1422 		/* nii_date */
1423 		status = nfsd4_decode_time(argp, &exid->nii_time);
1424 		if (status)
1425 			goto xdr_error;
1426 	}
1427 	DECODE_TAIL;
1428 }
1429 
1430 static __be32
1431 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1432 			    struct nfsd4_create_session *sess)
1433 {
1434 	DECODE_HEAD;
1435 
1436 	READ_BUF(16);
1437 	COPYMEM(&sess->clientid, 8);
1438 	sess->seqid = be32_to_cpup(p++);
1439 	sess->flags = be32_to_cpup(p++);
1440 
1441 	/* Fore channel attrs */
1442 	READ_BUF(28);
1443 	p++; /* headerpadsz is always 0 */
1444 	sess->fore_channel.maxreq_sz = be32_to_cpup(p++);
1445 	sess->fore_channel.maxresp_sz = be32_to_cpup(p++);
1446 	sess->fore_channel.maxresp_cached = be32_to_cpup(p++);
1447 	sess->fore_channel.maxops = be32_to_cpup(p++);
1448 	sess->fore_channel.maxreqs = be32_to_cpup(p++);
1449 	sess->fore_channel.nr_rdma_attrs = be32_to_cpup(p++);
1450 	if (sess->fore_channel.nr_rdma_attrs == 1) {
1451 		READ_BUF(4);
1452 		sess->fore_channel.rdma_attrs = be32_to_cpup(p++);
1453 	} else if (sess->fore_channel.nr_rdma_attrs > 1) {
1454 		dprintk("Too many fore channel attr bitmaps!\n");
1455 		goto xdr_error;
1456 	}
1457 
1458 	/* Back channel attrs */
1459 	READ_BUF(28);
1460 	p++; /* headerpadsz is always 0 */
1461 	sess->back_channel.maxreq_sz = be32_to_cpup(p++);
1462 	sess->back_channel.maxresp_sz = be32_to_cpup(p++);
1463 	sess->back_channel.maxresp_cached = be32_to_cpup(p++);
1464 	sess->back_channel.maxops = be32_to_cpup(p++);
1465 	sess->back_channel.maxreqs = be32_to_cpup(p++);
1466 	sess->back_channel.nr_rdma_attrs = be32_to_cpup(p++);
1467 	if (sess->back_channel.nr_rdma_attrs == 1) {
1468 		READ_BUF(4);
1469 		sess->back_channel.rdma_attrs = be32_to_cpup(p++);
1470 	} else if (sess->back_channel.nr_rdma_attrs > 1) {
1471 		dprintk("Too many back channel attr bitmaps!\n");
1472 		goto xdr_error;
1473 	}
1474 
1475 	READ_BUF(4);
1476 	sess->callback_prog = be32_to_cpup(p++);
1477 	nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1478 	DECODE_TAIL;
1479 }
1480 
1481 static __be32
1482 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1483 			     struct nfsd4_destroy_session *destroy_session)
1484 {
1485 	DECODE_HEAD;
1486 	READ_BUF(NFS4_MAX_SESSIONID_LEN);
1487 	COPYMEM(destroy_session->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1488 
1489 	DECODE_TAIL;
1490 }
1491 
1492 static __be32
1493 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1494 			  struct nfsd4_free_stateid *free_stateid)
1495 {
1496 	DECODE_HEAD;
1497 
1498 	READ_BUF(sizeof(stateid_t));
1499 	free_stateid->fr_stateid.si_generation = be32_to_cpup(p++);
1500 	COPYMEM(&free_stateid->fr_stateid.si_opaque, sizeof(stateid_opaque_t));
1501 
1502 	DECODE_TAIL;
1503 }
1504 
1505 static __be32
1506 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1507 		      struct nfsd4_sequence *seq)
1508 {
1509 	DECODE_HEAD;
1510 
1511 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
1512 	COPYMEM(seq->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1513 	seq->seqid = be32_to_cpup(p++);
1514 	seq->slotid = be32_to_cpup(p++);
1515 	seq->maxslots = be32_to_cpup(p++);
1516 	seq->cachethis = be32_to_cpup(p++);
1517 
1518 	DECODE_TAIL;
1519 }
1520 
1521 static __be32
1522 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1523 {
1524 	int i;
1525 	__be32 *p, status;
1526 	struct nfsd4_test_stateid_id *stateid;
1527 
1528 	READ_BUF(4);
1529 	test_stateid->ts_num_ids = ntohl(*p++);
1530 
1531 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1532 
1533 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1534 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1535 		if (!stateid) {
1536 			status = nfserrno(-ENOMEM);
1537 			goto out;
1538 		}
1539 
1540 		INIT_LIST_HEAD(&stateid->ts_id_list);
1541 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1542 
1543 		status = nfsd4_decode_stateid(argp, &stateid->ts_id_stateid);
1544 		if (status)
1545 			goto out;
1546 	}
1547 
1548 	status = 0;
1549 out:
1550 	return status;
1551 xdr_error:
1552 	dprintk("NFSD: xdr error (%s:%d)\n", __FILE__, __LINE__);
1553 	status = nfserr_bad_xdr;
1554 	goto out;
1555 }
1556 
1557 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp, struct nfsd4_destroy_clientid *dc)
1558 {
1559 	DECODE_HEAD;
1560 
1561 	READ_BUF(8);
1562 	COPYMEM(&dc->clientid, 8);
1563 
1564 	DECODE_TAIL;
1565 }
1566 
1567 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, struct nfsd4_reclaim_complete *rc)
1568 {
1569 	DECODE_HEAD;
1570 
1571 	READ_BUF(4);
1572 	rc->rca_one_fs = be32_to_cpup(p++);
1573 
1574 	DECODE_TAIL;
1575 }
1576 
1577 #ifdef CONFIG_NFSD_PNFS
1578 static __be32
1579 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1580 		struct nfsd4_getdeviceinfo *gdev)
1581 {
1582 	DECODE_HEAD;
1583 	u32 num, i;
1584 
1585 	READ_BUF(sizeof(struct nfsd4_deviceid) + 3 * 4);
1586 	COPYMEM(&gdev->gd_devid, sizeof(struct nfsd4_deviceid));
1587 	gdev->gd_layout_type = be32_to_cpup(p++);
1588 	gdev->gd_maxcount = be32_to_cpup(p++);
1589 	num = be32_to_cpup(p++);
1590 	if (num) {
1591 		if (num > 1000)
1592 			goto xdr_error;
1593 		READ_BUF(4 * num);
1594 		gdev->gd_notify_types = be32_to_cpup(p++);
1595 		for (i = 1; i < num; i++) {
1596 			if (be32_to_cpup(p++)) {
1597 				status = nfserr_inval;
1598 				goto out;
1599 			}
1600 		}
1601 	}
1602 	DECODE_TAIL;
1603 }
1604 
1605 static __be32
1606 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1607 		struct nfsd4_layoutget *lgp)
1608 {
1609 	DECODE_HEAD;
1610 
1611 	READ_BUF(36);
1612 	lgp->lg_signal = be32_to_cpup(p++);
1613 	lgp->lg_layout_type = be32_to_cpup(p++);
1614 	lgp->lg_seg.iomode = be32_to_cpup(p++);
1615 	p = xdr_decode_hyper(p, &lgp->lg_seg.offset);
1616 	p = xdr_decode_hyper(p, &lgp->lg_seg.length);
1617 	p = xdr_decode_hyper(p, &lgp->lg_minlength);
1618 
1619 	status = nfsd4_decode_stateid(argp, &lgp->lg_sid);
1620 	if (status)
1621 		return status;
1622 
1623 	READ_BUF(4);
1624 	lgp->lg_maxcount = be32_to_cpup(p++);
1625 
1626 	DECODE_TAIL;
1627 }
1628 
1629 static __be32
1630 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1631 		struct nfsd4_layoutcommit *lcp)
1632 {
1633 	DECODE_HEAD;
1634 	u32 timechange;
1635 
1636 	READ_BUF(20);
1637 	p = xdr_decode_hyper(p, &lcp->lc_seg.offset);
1638 	p = xdr_decode_hyper(p, &lcp->lc_seg.length);
1639 	lcp->lc_reclaim = be32_to_cpup(p++);
1640 
1641 	status = nfsd4_decode_stateid(argp, &lcp->lc_sid);
1642 	if (status)
1643 		return status;
1644 
1645 	READ_BUF(4);
1646 	lcp->lc_newoffset = be32_to_cpup(p++);
1647 	if (lcp->lc_newoffset) {
1648 		READ_BUF(8);
1649 		p = xdr_decode_hyper(p, &lcp->lc_last_wr);
1650 	} else
1651 		lcp->lc_last_wr = 0;
1652 	READ_BUF(4);
1653 	timechange = be32_to_cpup(p++);
1654 	if (timechange) {
1655 		status = nfsd4_decode_time(argp, &lcp->lc_mtime);
1656 		if (status)
1657 			return status;
1658 	} else {
1659 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1660 	}
1661 	READ_BUF(8);
1662 	lcp->lc_layout_type = be32_to_cpup(p++);
1663 
1664 	/*
1665 	 * Save the layout update in XDR format and let the layout driver deal
1666 	 * with it later.
1667 	 */
1668 	lcp->lc_up_len = be32_to_cpup(p++);
1669 	if (lcp->lc_up_len > 0) {
1670 		READ_BUF(lcp->lc_up_len);
1671 		READMEM(lcp->lc_up_layout, lcp->lc_up_len);
1672 	}
1673 
1674 	DECODE_TAIL;
1675 }
1676 
1677 static __be32
1678 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1679 		struct nfsd4_layoutreturn *lrp)
1680 {
1681 	DECODE_HEAD;
1682 
1683 	READ_BUF(16);
1684 	lrp->lr_reclaim = be32_to_cpup(p++);
1685 	lrp->lr_layout_type = be32_to_cpup(p++);
1686 	lrp->lr_seg.iomode = be32_to_cpup(p++);
1687 	lrp->lr_return_type = be32_to_cpup(p++);
1688 	if (lrp->lr_return_type == RETURN_FILE) {
1689 		READ_BUF(16);
1690 		p = xdr_decode_hyper(p, &lrp->lr_seg.offset);
1691 		p = xdr_decode_hyper(p, &lrp->lr_seg.length);
1692 
1693 		status = nfsd4_decode_stateid(argp, &lrp->lr_sid);
1694 		if (status)
1695 			return status;
1696 
1697 		READ_BUF(4);
1698 		lrp->lrf_body_len = be32_to_cpup(p++);
1699 		if (lrp->lrf_body_len > 0) {
1700 			READ_BUF(lrp->lrf_body_len);
1701 			READMEM(lrp->lrf_body, lrp->lrf_body_len);
1702 		}
1703 	} else {
1704 		lrp->lr_seg.offset = 0;
1705 		lrp->lr_seg.length = NFS4_MAX_UINT64;
1706 	}
1707 
1708 	DECODE_TAIL;
1709 }
1710 #endif /* CONFIG_NFSD_PNFS */
1711 
1712 static __be32
1713 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1714 		       struct nfsd4_fallocate *fallocate)
1715 {
1716 	DECODE_HEAD;
1717 
1718 	status = nfsd4_decode_stateid(argp, &fallocate->falloc_stateid);
1719 	if (status)
1720 		return status;
1721 
1722 	READ_BUF(16);
1723 	p = xdr_decode_hyper(p, &fallocate->falloc_offset);
1724 	xdr_decode_hyper(p, &fallocate->falloc_length);
1725 
1726 	DECODE_TAIL;
1727 }
1728 
1729 static __be32
1730 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
1731 {
1732 	DECODE_HEAD;
1733 
1734 	status = nfsd4_decode_stateid(argp, &clone->cl_src_stateid);
1735 	if (status)
1736 		return status;
1737 	status = nfsd4_decode_stateid(argp, &clone->cl_dst_stateid);
1738 	if (status)
1739 		return status;
1740 
1741 	READ_BUF(8 + 8 + 8);
1742 	p = xdr_decode_hyper(p, &clone->cl_src_pos);
1743 	p = xdr_decode_hyper(p, &clone->cl_dst_pos);
1744 	p = xdr_decode_hyper(p, &clone->cl_count);
1745 	DECODE_TAIL;
1746 }
1747 
1748 static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
1749 				      struct nl4_server *ns)
1750 {
1751 	DECODE_HEAD;
1752 	struct nfs42_netaddr *naddr;
1753 
1754 	READ_BUF(4);
1755 	ns->nl4_type = be32_to_cpup(p++);
1756 
1757 	/* currently support for 1 inter-server source server */
1758 	switch (ns->nl4_type) {
1759 	case NL4_NETADDR:
1760 		naddr = &ns->u.nl4_addr;
1761 
1762 		READ_BUF(4);
1763 		naddr->netid_len = be32_to_cpup(p++);
1764 		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
1765 			goto xdr_error;
1766 
1767 		READ_BUF(naddr->netid_len + 4); /* 4 for uaddr len */
1768 		COPYMEM(naddr->netid, naddr->netid_len);
1769 
1770 		naddr->addr_len = be32_to_cpup(p++);
1771 		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
1772 			goto xdr_error;
1773 
1774 		READ_BUF(naddr->addr_len);
1775 		COPYMEM(naddr->addr, naddr->addr_len);
1776 		break;
1777 	default:
1778 		goto xdr_error;
1779 	}
1780 	DECODE_TAIL;
1781 }
1782 
1783 static __be32
1784 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
1785 {
1786 	DECODE_HEAD;
1787 	struct nl4_server *ns_dummy;
1788 	int i, count;
1789 
1790 	status = nfsd4_decode_stateid(argp, &copy->cp_src_stateid);
1791 	if (status)
1792 		return status;
1793 	status = nfsd4_decode_stateid(argp, &copy->cp_dst_stateid);
1794 	if (status)
1795 		return status;
1796 
1797 	READ_BUF(8 + 8 + 8 + 4 + 4 + 4);
1798 	p = xdr_decode_hyper(p, &copy->cp_src_pos);
1799 	p = xdr_decode_hyper(p, &copy->cp_dst_pos);
1800 	p = xdr_decode_hyper(p, &copy->cp_count);
1801 	p++; /* ca_consecutive: we always do consecutive copies */
1802 	copy->cp_synchronous = be32_to_cpup(p++);
1803 
1804 	count = be32_to_cpup(p++);
1805 
1806 	copy->cp_intra = false;
1807 	if (count == 0) { /* intra-server copy */
1808 		copy->cp_intra = true;
1809 		goto intra;
1810 	}
1811 
1812 	/* decode all the supplied server addresses but use first */
1813 	status = nfsd4_decode_nl4_server(argp, &copy->cp_src);
1814 	if (status)
1815 		return status;
1816 
1817 	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
1818 	if (ns_dummy == NULL)
1819 		return nfserrno(-ENOMEM);
1820 	for (i = 0; i < count - 1; i++) {
1821 		status = nfsd4_decode_nl4_server(argp, ns_dummy);
1822 		if (status) {
1823 			kfree(ns_dummy);
1824 			return status;
1825 		}
1826 	}
1827 	kfree(ns_dummy);
1828 intra:
1829 
1830 	DECODE_TAIL;
1831 }
1832 
1833 static __be32
1834 nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
1835 			    struct nfsd4_offload_status *os)
1836 {
1837 	return nfsd4_decode_stateid(argp, &os->stateid);
1838 }
1839 
1840 static __be32
1841 nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
1842 			 struct nfsd4_copy_notify *cn)
1843 {
1844 	int status;
1845 
1846 	status = nfsd4_decode_stateid(argp, &cn->cpn_src_stateid);
1847 	if (status)
1848 		return status;
1849 	return nfsd4_decode_nl4_server(argp, &cn->cpn_dst);
1850 }
1851 
1852 static __be32
1853 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
1854 {
1855 	DECODE_HEAD;
1856 
1857 	status = nfsd4_decode_stateid(argp, &seek->seek_stateid);
1858 	if (status)
1859 		return status;
1860 
1861 	READ_BUF(8 + 4);
1862 	p = xdr_decode_hyper(p, &seek->seek_offset);
1863 	seek->seek_whence = be32_to_cpup(p);
1864 
1865 	DECODE_TAIL;
1866 }
1867 
1868 static __be32
1869 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
1870 {
1871 	return nfs_ok;
1872 }
1873 
1874 static __be32
1875 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
1876 {
1877 	return nfserr_notsupp;
1878 }
1879 
1880 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
1881 
1882 static const nfsd4_dec nfsd4_dec_ops[] = {
1883 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
1884 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
1885 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
1886 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
1887 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1888 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
1889 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
1890 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
1891 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
1892 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
1893 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
1894 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
1895 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
1896 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
1897 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1898 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
1899 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
1900 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
1901 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
1902 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
1903 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
1904 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
1905 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
1906 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
1907 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
1908 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
1909 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
1910 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
1911 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
1912 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
1913 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
1914 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
1915 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
1916 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
1917 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1918 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
1919 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
1920 
1921 	/* new operations for NFSv4.1 */
1922 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
1923 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
1924 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
1925 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
1926 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
1927 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
1928 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1929 #ifdef CONFIG_NFSD_PNFS
1930 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
1931 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
1932 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
1933 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
1934 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
1935 #else
1936 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
1937 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
1938 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
1939 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
1940 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
1941 #endif
1942 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
1943 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
1944 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
1945 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
1946 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1947 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
1948 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
1949 
1950 	/* new operations for NFSv4.2 */
1951 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
1952 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
1953 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_copy_notify,
1954 	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
1955 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1956 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
1957 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
1958 	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_offload_status,
1959 	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_offload_status,
1960 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_notsupp,
1961 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
1962 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
1963 	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
1964 };
1965 
1966 static inline bool
1967 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
1968 {
1969 	if (op->opnum < FIRST_NFS4_OP)
1970 		return false;
1971 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
1972 		return false;
1973 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
1974 		return false;
1975 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
1976 		return false;
1977 	return true;
1978 }
1979 
1980 static __be32
1981 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
1982 {
1983 	DECODE_HEAD;
1984 	struct nfsd4_op *op;
1985 	bool cachethis = false;
1986 	int auth_slack= argp->rqstp->rq_auth_slack;
1987 	int max_reply = auth_slack + 8; /* opcnt, status */
1988 	int readcount = 0;
1989 	int readbytes = 0;
1990 	int i;
1991 
1992 	READ_BUF(4);
1993 	argp->taglen = be32_to_cpup(p++);
1994 	READ_BUF(argp->taglen);
1995 	SAVEMEM(argp->tag, argp->taglen);
1996 	READ_BUF(8);
1997 	argp->minorversion = be32_to_cpup(p++);
1998 	argp->opcnt = be32_to_cpup(p++);
1999 	max_reply += 4 + (XDR_QUADLEN(argp->taglen) << 2);
2000 
2001 	if (argp->taglen > NFSD4_MAX_TAGLEN)
2002 		goto xdr_error;
2003 	/*
2004 	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
2005 	 * here, so we return success at the xdr level so that
2006 	 * nfsd4_proc can handle this is an NFS-level error.
2007 	 */
2008 	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
2009 		return 0;
2010 
2011 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
2012 		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
2013 		if (!argp->ops) {
2014 			argp->ops = argp->iops;
2015 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
2016 			goto xdr_error;
2017 		}
2018 	}
2019 
2020 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
2021 		argp->opcnt = 0;
2022 
2023 	for (i = 0; i < argp->opcnt; i++) {
2024 		op = &argp->ops[i];
2025 		op->replay = NULL;
2026 
2027 		READ_BUF(4);
2028 		op->opnum = be32_to_cpup(p++);
2029 
2030 		if (nfsd4_opnum_in_range(argp, op))
2031 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
2032 		else {
2033 			op->opnum = OP_ILLEGAL;
2034 			op->status = nfserr_op_illegal;
2035 		}
2036 		op->opdesc = OPDESC(op);
2037 		/*
2038 		 * We'll try to cache the result in the DRC if any one
2039 		 * op in the compound wants to be cached:
2040 		 */
2041 		cachethis |= nfsd4_cache_this_op(op);
2042 
2043 		if (op->opnum == OP_READ) {
2044 			readcount++;
2045 			readbytes += nfsd4_max_reply(argp->rqstp, op);
2046 		} else
2047 			max_reply += nfsd4_max_reply(argp->rqstp, op);
2048 		/*
2049 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
2050 		 * (Special case because it will just skip encoding this
2051 		 * if it runs out of xdr buffer space, and it is the only
2052 		 * operation that behaves this way.)
2053 		 */
2054 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
2055 			max_reply += NFS4_OPAQUE_LIMIT;
2056 
2057 		if (op->status) {
2058 			argp->opcnt = i+1;
2059 			break;
2060 		}
2061 	}
2062 	/* Sessions make the DRC unnecessary: */
2063 	if (argp->minorversion)
2064 		cachethis = false;
2065 	svc_reserve(argp->rqstp, max_reply + readbytes);
2066 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
2067 
2068 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
2069 		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
2070 
2071 	DECODE_TAIL;
2072 }
2073 
2074 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
2075 			     struct svc_export *exp)
2076 {
2077 	if (exp->ex_flags & NFSEXP_V4ROOT) {
2078 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
2079 		*p++ = 0;
2080 	} else if (IS_I_VERSION(inode)) {
2081 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2082 	} else {
2083 		*p++ = cpu_to_be32(stat->ctime.tv_sec);
2084 		*p++ = cpu_to_be32(stat->ctime.tv_nsec);
2085 	}
2086 	return p;
2087 }
2088 
2089 /*
2090  * ctime (in NFSv4, time_metadata) is not writeable, and the client
2091  * doesn't really care what resolution could theoretically be stored by
2092  * the filesystem.
2093  *
2094  * The client cares how close together changes can be while still
2095  * guaranteeing ctime changes.  For most filesystems (which have
2096  * timestamps with nanosecond fields) that is limited by the resolution
2097  * of the time returned from current_time() (which I'm assuming to be
2098  * 1/HZ).
2099  */
2100 static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
2101 {
2102 	struct timespec64 ts;
2103 	u32 ns;
2104 
2105 	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
2106 	ts = ns_to_timespec64(ns);
2107 
2108 	p = xdr_encode_hyper(p, ts.tv_sec);
2109 	*p++ = cpu_to_be32(ts.tv_nsec);
2110 
2111 	return p;
2112 }
2113 
2114 static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
2115 {
2116 	*p++ = cpu_to_be32(c->atomic);
2117 	if (c->change_supported) {
2118 		p = xdr_encode_hyper(p, c->before_change);
2119 		p = xdr_encode_hyper(p, c->after_change);
2120 	} else {
2121 		*p++ = cpu_to_be32(c->before_ctime_sec);
2122 		*p++ = cpu_to_be32(c->before_ctime_nsec);
2123 		*p++ = cpu_to_be32(c->after_ctime_sec);
2124 		*p++ = cpu_to_be32(c->after_ctime_nsec);
2125 	}
2126 	return p;
2127 }
2128 
2129 /* Encode as an array of strings the string given with components
2130  * separated @sep, escaped with esc_enter and esc_exit.
2131  */
2132 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2133 					  char *components, char esc_enter,
2134 					  char esc_exit)
2135 {
2136 	__be32 *p;
2137 	__be32 pathlen;
2138 	int pathlen_offset;
2139 	int strlen, count=0;
2140 	char *str, *end, *next;
2141 
2142 	dprintk("nfsd4_encode_components(%s)\n", components);
2143 
2144 	pathlen_offset = xdr->buf->len;
2145 	p = xdr_reserve_space(xdr, 4);
2146 	if (!p)
2147 		return nfserr_resource;
2148 	p++; /* We will fill this in with @count later */
2149 
2150 	end = str = components;
2151 	while (*end) {
2152 		bool found_esc = false;
2153 
2154 		/* try to parse as esc_start, ..., esc_end, sep */
2155 		if (*str == esc_enter) {
2156 			for (; *end && (*end != esc_exit); end++)
2157 				/* find esc_exit or end of string */;
2158 			next = end + 1;
2159 			if (*end && (!*next || *next == sep)) {
2160 				str++;
2161 				found_esc = true;
2162 			}
2163 		}
2164 
2165 		if (!found_esc)
2166 			for (; *end && (*end != sep); end++)
2167 				/* find sep or end of string */;
2168 
2169 		strlen = end - str;
2170 		if (strlen) {
2171 			p = xdr_reserve_space(xdr, strlen + 4);
2172 			if (!p)
2173 				return nfserr_resource;
2174 			p = xdr_encode_opaque(p, str, strlen);
2175 			count++;
2176 		}
2177 		else
2178 			end++;
2179 		if (found_esc)
2180 			end = next;
2181 
2182 		str = end;
2183 	}
2184 	pathlen = htonl(count);
2185 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2186 	return 0;
2187 }
2188 
2189 /* Encode as an array of strings the string given with components
2190  * separated @sep.
2191  */
2192 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2193 				      char *components)
2194 {
2195 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2196 }
2197 
2198 /*
2199  * encode a location element of a fs_locations structure
2200  */
2201 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2202 					struct nfsd4_fs_location *location)
2203 {
2204 	__be32 status;
2205 
2206 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2207 						'[', ']');
2208 	if (status)
2209 		return status;
2210 	status = nfsd4_encode_components(xdr, '/', location->path);
2211 	if (status)
2212 		return status;
2213 	return 0;
2214 }
2215 
2216 /*
2217  * Encode a path in RFC3530 'pathname4' format
2218  */
2219 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2220 				const struct path *root,
2221 				const struct path *path)
2222 {
2223 	struct path cur = *path;
2224 	__be32 *p;
2225 	struct dentry **components = NULL;
2226 	unsigned int ncomponents = 0;
2227 	__be32 err = nfserr_jukebox;
2228 
2229 	dprintk("nfsd4_encode_components(");
2230 
2231 	path_get(&cur);
2232 	/* First walk the path up to the nfsd root, and store the
2233 	 * dentries/path components in an array.
2234 	 */
2235 	for (;;) {
2236 		if (path_equal(&cur, root))
2237 			break;
2238 		if (cur.dentry == cur.mnt->mnt_root) {
2239 			if (follow_up(&cur))
2240 				continue;
2241 			goto out_free;
2242 		}
2243 		if ((ncomponents & 15) == 0) {
2244 			struct dentry **new;
2245 			new = krealloc(components,
2246 					sizeof(*new) * (ncomponents + 16),
2247 					GFP_KERNEL);
2248 			if (!new)
2249 				goto out_free;
2250 			components = new;
2251 		}
2252 		components[ncomponents++] = cur.dentry;
2253 		cur.dentry = dget_parent(cur.dentry);
2254 	}
2255 	err = nfserr_resource;
2256 	p = xdr_reserve_space(xdr, 4);
2257 	if (!p)
2258 		goto out_free;
2259 	*p++ = cpu_to_be32(ncomponents);
2260 
2261 	while (ncomponents) {
2262 		struct dentry *dentry = components[ncomponents - 1];
2263 		unsigned int len;
2264 
2265 		spin_lock(&dentry->d_lock);
2266 		len = dentry->d_name.len;
2267 		p = xdr_reserve_space(xdr, len + 4);
2268 		if (!p) {
2269 			spin_unlock(&dentry->d_lock);
2270 			goto out_free;
2271 		}
2272 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2273 		dprintk("/%pd", dentry);
2274 		spin_unlock(&dentry->d_lock);
2275 		dput(dentry);
2276 		ncomponents--;
2277 	}
2278 
2279 	err = 0;
2280 out_free:
2281 	dprintk(")\n");
2282 	while (ncomponents)
2283 		dput(components[--ncomponents]);
2284 	kfree(components);
2285 	path_put(&cur);
2286 	return err;
2287 }
2288 
2289 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2290 			struct svc_rqst *rqstp, const struct path *path)
2291 {
2292 	struct svc_export *exp_ps;
2293 	__be32 res;
2294 
2295 	exp_ps = rqst_find_fsidzero_export(rqstp);
2296 	if (IS_ERR(exp_ps))
2297 		return nfserrno(PTR_ERR(exp_ps));
2298 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2299 	exp_put(exp_ps);
2300 	return res;
2301 }
2302 
2303 /*
2304  *  encode a fs_locations structure
2305  */
2306 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2307 			struct svc_rqst *rqstp, struct svc_export *exp)
2308 {
2309 	__be32 status;
2310 	int i;
2311 	__be32 *p;
2312 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2313 
2314 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2315 	if (status)
2316 		return status;
2317 	p = xdr_reserve_space(xdr, 4);
2318 	if (!p)
2319 		return nfserr_resource;
2320 	*p++ = cpu_to_be32(fslocs->locations_count);
2321 	for (i=0; i<fslocs->locations_count; i++) {
2322 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2323 		if (status)
2324 			return status;
2325 	}
2326 	return 0;
2327 }
2328 
2329 static u32 nfs4_file_type(umode_t mode)
2330 {
2331 	switch (mode & S_IFMT) {
2332 	case S_IFIFO:	return NF4FIFO;
2333 	case S_IFCHR:	return NF4CHR;
2334 	case S_IFDIR:	return NF4DIR;
2335 	case S_IFBLK:	return NF4BLK;
2336 	case S_IFLNK:	return NF4LNK;
2337 	case S_IFREG:	return NF4REG;
2338 	case S_IFSOCK:	return NF4SOCK;
2339 	default:	return NF4BAD;
2340 	};
2341 }
2342 
2343 static inline __be32
2344 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2345 		     struct nfs4_ace *ace)
2346 {
2347 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2348 		return nfs4_acl_write_who(xdr, ace->whotype);
2349 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2350 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2351 	else
2352 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2353 }
2354 
2355 static inline __be32
2356 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2357 {
2358 	__be32		*p;
2359 	unsigned long	i = hweight_long(layout_types);
2360 
2361 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2362 	if (!p)
2363 		return nfserr_resource;
2364 
2365 	*p++ = cpu_to_be32(i);
2366 
2367 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2368 		if (layout_types & (1 << i))
2369 			*p++ = cpu_to_be32(i);
2370 
2371 	return 0;
2372 }
2373 
2374 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2375 			      FATTR4_WORD0_RDATTR_ERROR)
2376 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2377 #define WORD2_ABSENT_FS_ATTRS 0
2378 
2379 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2380 static inline __be32
2381 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2382 			    void *context, int len)
2383 {
2384 	__be32 *p;
2385 
2386 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2387 	if (!p)
2388 		return nfserr_resource;
2389 
2390 	/*
2391 	 * For now we use a 0 here to indicate the null translation; in
2392 	 * the future we may place a call to translation code here.
2393 	 */
2394 	*p++ = cpu_to_be32(0); /* lfs */
2395 	*p++ = cpu_to_be32(0); /* pi */
2396 	p = xdr_encode_opaque(p, context, len);
2397 	return 0;
2398 }
2399 #else
2400 static inline __be32
2401 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2402 			    void *context, int len)
2403 { return 0; }
2404 #endif
2405 
2406 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2407 {
2408 	/* As per referral draft:  */
2409 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2410 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2411 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2412 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2413 			*rdattr_err = NFSERR_MOVED;
2414 		else
2415 			return nfserr_moved;
2416 	}
2417 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2418 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2419 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2420 	return 0;
2421 }
2422 
2423 
2424 static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
2425 {
2426 	struct path path = exp->ex_path;
2427 	int err;
2428 
2429 	path_get(&path);
2430 	while (follow_up(&path)) {
2431 		if (path.dentry != path.mnt->mnt_root)
2432 			break;
2433 	}
2434 	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2435 	path_put(&path);
2436 	return err;
2437 }
2438 
2439 static __be32
2440 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2441 {
2442 	__be32 *p;
2443 
2444 	if (bmval2) {
2445 		p = xdr_reserve_space(xdr, 16);
2446 		if (!p)
2447 			goto out_resource;
2448 		*p++ = cpu_to_be32(3);
2449 		*p++ = cpu_to_be32(bmval0);
2450 		*p++ = cpu_to_be32(bmval1);
2451 		*p++ = cpu_to_be32(bmval2);
2452 	} else if (bmval1) {
2453 		p = xdr_reserve_space(xdr, 12);
2454 		if (!p)
2455 			goto out_resource;
2456 		*p++ = cpu_to_be32(2);
2457 		*p++ = cpu_to_be32(bmval0);
2458 		*p++ = cpu_to_be32(bmval1);
2459 	} else {
2460 		p = xdr_reserve_space(xdr, 8);
2461 		if (!p)
2462 			goto out_resource;
2463 		*p++ = cpu_to_be32(1);
2464 		*p++ = cpu_to_be32(bmval0);
2465 	}
2466 
2467 	return 0;
2468 out_resource:
2469 	return nfserr_resource;
2470 }
2471 
2472 /*
2473  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2474  * ourselves.
2475  */
2476 static __be32
2477 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2478 		struct svc_export *exp,
2479 		struct dentry *dentry, u32 *bmval,
2480 		struct svc_rqst *rqstp, int ignore_crossmnt)
2481 {
2482 	u32 bmval0 = bmval[0];
2483 	u32 bmval1 = bmval[1];
2484 	u32 bmval2 = bmval[2];
2485 	struct kstat stat;
2486 	struct svc_fh *tempfh = NULL;
2487 	struct kstatfs statfs;
2488 	__be32 *p;
2489 	int starting_len = xdr->buf->len;
2490 	int attrlen_offset;
2491 	__be32 attrlen;
2492 	u32 dummy;
2493 	u64 dummy64;
2494 	u32 rdattr_err = 0;
2495 	__be32 status;
2496 	int err;
2497 	struct nfs4_acl *acl = NULL;
2498 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2499 	void *context = NULL;
2500 	int contextlen;
2501 #endif
2502 	bool contextsupport = false;
2503 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2504 	u32 minorversion = resp->cstate.minorversion;
2505 	struct path path = {
2506 		.mnt	= exp->ex_path.mnt,
2507 		.dentry	= dentry,
2508 	};
2509 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2510 
2511 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2512 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2513 
2514 	if (exp->ex_fslocs.migrated) {
2515 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2516 		if (status)
2517 			goto out;
2518 	}
2519 
2520 	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2521 	if (err)
2522 		goto out_nfserr;
2523 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
2524 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
2525 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2526 		       FATTR4_WORD1_SPACE_TOTAL))) {
2527 		err = vfs_statfs(&path, &statfs);
2528 		if (err)
2529 			goto out_nfserr;
2530 	}
2531 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2532 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
2533 		status = nfserr_jukebox;
2534 		if (!tempfh)
2535 			goto out;
2536 		fh_init(tempfh, NFS4_FHSIZE);
2537 		status = fh_compose(tempfh, exp, dentry, NULL);
2538 		if (status)
2539 			goto out;
2540 		fhp = tempfh;
2541 	}
2542 	if (bmval0 & FATTR4_WORD0_ACL) {
2543 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2544 		if (err == -EOPNOTSUPP)
2545 			bmval0 &= ~FATTR4_WORD0_ACL;
2546 		else if (err == -EINVAL) {
2547 			status = nfserr_attrnotsupp;
2548 			goto out;
2549 		} else if (err != 0)
2550 			goto out_nfserr;
2551 	}
2552 
2553 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2554 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
2555 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2556 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
2557 			err = security_inode_getsecctx(d_inode(dentry),
2558 						&context, &contextlen);
2559 		else
2560 			err = -EOPNOTSUPP;
2561 		contextsupport = (err == 0);
2562 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2563 			if (err == -EOPNOTSUPP)
2564 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
2565 			else if (err)
2566 				goto out_nfserr;
2567 		}
2568 	}
2569 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2570 
2571 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
2572 	if (status)
2573 		goto out;
2574 
2575 	attrlen_offset = xdr->buf->len;
2576 	p = xdr_reserve_space(xdr, 4);
2577 	if (!p)
2578 		goto out_resource;
2579 	p++;                /* to be backfilled later */
2580 
2581 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2582 		u32 supp[3];
2583 
2584 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2585 
2586 		if (!IS_POSIXACL(dentry->d_inode))
2587 			supp[0] &= ~FATTR4_WORD0_ACL;
2588 		if (!contextsupport)
2589 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2590 		if (!supp[2]) {
2591 			p = xdr_reserve_space(xdr, 12);
2592 			if (!p)
2593 				goto out_resource;
2594 			*p++ = cpu_to_be32(2);
2595 			*p++ = cpu_to_be32(supp[0]);
2596 			*p++ = cpu_to_be32(supp[1]);
2597 		} else {
2598 			p = xdr_reserve_space(xdr, 16);
2599 			if (!p)
2600 				goto out_resource;
2601 			*p++ = cpu_to_be32(3);
2602 			*p++ = cpu_to_be32(supp[0]);
2603 			*p++ = cpu_to_be32(supp[1]);
2604 			*p++ = cpu_to_be32(supp[2]);
2605 		}
2606 	}
2607 	if (bmval0 & FATTR4_WORD0_TYPE) {
2608 		p = xdr_reserve_space(xdr, 4);
2609 		if (!p)
2610 			goto out_resource;
2611 		dummy = nfs4_file_type(stat.mode);
2612 		if (dummy == NF4BAD) {
2613 			status = nfserr_serverfault;
2614 			goto out;
2615 		}
2616 		*p++ = cpu_to_be32(dummy);
2617 	}
2618 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2619 		p = xdr_reserve_space(xdr, 4);
2620 		if (!p)
2621 			goto out_resource;
2622 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2623 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
2624 		else
2625 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
2626 						NFS4_FH_VOL_RENAME);
2627 	}
2628 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2629 		p = xdr_reserve_space(xdr, 8);
2630 		if (!p)
2631 			goto out_resource;
2632 		p = encode_change(p, &stat, d_inode(dentry), exp);
2633 	}
2634 	if (bmval0 & FATTR4_WORD0_SIZE) {
2635 		p = xdr_reserve_space(xdr, 8);
2636 		if (!p)
2637 			goto out_resource;
2638 		p = xdr_encode_hyper(p, stat.size);
2639 	}
2640 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2641 		p = xdr_reserve_space(xdr, 4);
2642 		if (!p)
2643 			goto out_resource;
2644 		*p++ = cpu_to_be32(1);
2645 	}
2646 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
2647 		p = xdr_reserve_space(xdr, 4);
2648 		if (!p)
2649 			goto out_resource;
2650 		*p++ = cpu_to_be32(1);
2651 	}
2652 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
2653 		p = xdr_reserve_space(xdr, 4);
2654 		if (!p)
2655 			goto out_resource;
2656 		*p++ = cpu_to_be32(0);
2657 	}
2658 	if (bmval0 & FATTR4_WORD0_FSID) {
2659 		p = xdr_reserve_space(xdr, 16);
2660 		if (!p)
2661 			goto out_resource;
2662 		if (exp->ex_fslocs.migrated) {
2663 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
2664 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
2665 		} else switch(fsid_source(fhp)) {
2666 		case FSIDSOURCE_FSID:
2667 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
2668 			p = xdr_encode_hyper(p, (u64)0);
2669 			break;
2670 		case FSIDSOURCE_DEV:
2671 			*p++ = cpu_to_be32(0);
2672 			*p++ = cpu_to_be32(MAJOR(stat.dev));
2673 			*p++ = cpu_to_be32(0);
2674 			*p++ = cpu_to_be32(MINOR(stat.dev));
2675 			break;
2676 		case FSIDSOURCE_UUID:
2677 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
2678 								EX_UUID_LEN);
2679 			break;
2680 		}
2681 	}
2682 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
2683 		p = xdr_reserve_space(xdr, 4);
2684 		if (!p)
2685 			goto out_resource;
2686 		*p++ = cpu_to_be32(0);
2687 	}
2688 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
2689 		p = xdr_reserve_space(xdr, 4);
2690 		if (!p)
2691 			goto out_resource;
2692 		*p++ = cpu_to_be32(nn->nfsd4_lease);
2693 	}
2694 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
2695 		p = xdr_reserve_space(xdr, 4);
2696 		if (!p)
2697 			goto out_resource;
2698 		*p++ = cpu_to_be32(rdattr_err);
2699 	}
2700 	if (bmval0 & FATTR4_WORD0_ACL) {
2701 		struct nfs4_ace *ace;
2702 
2703 		if (acl == NULL) {
2704 			p = xdr_reserve_space(xdr, 4);
2705 			if (!p)
2706 				goto out_resource;
2707 
2708 			*p++ = cpu_to_be32(0);
2709 			goto out_acl;
2710 		}
2711 		p = xdr_reserve_space(xdr, 4);
2712 		if (!p)
2713 			goto out_resource;
2714 		*p++ = cpu_to_be32(acl->naces);
2715 
2716 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
2717 			p = xdr_reserve_space(xdr, 4*3);
2718 			if (!p)
2719 				goto out_resource;
2720 			*p++ = cpu_to_be32(ace->type);
2721 			*p++ = cpu_to_be32(ace->flag);
2722 			*p++ = cpu_to_be32(ace->access_mask &
2723 							NFS4_ACE_MASK_ALL);
2724 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
2725 			if (status)
2726 				goto out;
2727 		}
2728 	}
2729 out_acl:
2730 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
2731 		p = xdr_reserve_space(xdr, 4);
2732 		if (!p)
2733 			goto out_resource;
2734 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
2735 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
2736 	}
2737 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
2738 		p = xdr_reserve_space(xdr, 4);
2739 		if (!p)
2740 			goto out_resource;
2741 		*p++ = cpu_to_be32(1);
2742 	}
2743 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
2744 		p = xdr_reserve_space(xdr, 4);
2745 		if (!p)
2746 			goto out_resource;
2747 		*p++ = cpu_to_be32(0);
2748 	}
2749 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
2750 		p = xdr_reserve_space(xdr, 4);
2751 		if (!p)
2752 			goto out_resource;
2753 		*p++ = cpu_to_be32(1);
2754 	}
2755 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
2756 		p = xdr_reserve_space(xdr, 4);
2757 		if (!p)
2758 			goto out_resource;
2759 		*p++ = cpu_to_be32(1);
2760 	}
2761 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
2762 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
2763 		if (!p)
2764 			goto out_resource;
2765 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base,
2766 					fhp->fh_handle.fh_size);
2767 	}
2768 	if (bmval0 & FATTR4_WORD0_FILEID) {
2769 		p = xdr_reserve_space(xdr, 8);
2770 		if (!p)
2771 			goto out_resource;
2772 		p = xdr_encode_hyper(p, stat.ino);
2773 	}
2774 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
2775 		p = xdr_reserve_space(xdr, 8);
2776 		if (!p)
2777 			goto out_resource;
2778 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
2779 	}
2780 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
2781 		p = xdr_reserve_space(xdr, 8);
2782 		if (!p)
2783 			goto out_resource;
2784 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
2785 	}
2786 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
2787 		p = xdr_reserve_space(xdr, 8);
2788 		if (!p)
2789 			goto out_resource;
2790 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
2791 	}
2792 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
2793 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
2794 		if (status)
2795 			goto out;
2796 	}
2797 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
2798 		p = xdr_reserve_space(xdr, 4);
2799 		if (!p)
2800 			goto out_resource;
2801 		*p++ = cpu_to_be32(1);
2802 	}
2803 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
2804 		p = xdr_reserve_space(xdr, 8);
2805 		if (!p)
2806 			goto out_resource;
2807 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
2808 	}
2809 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
2810 		p = xdr_reserve_space(xdr, 4);
2811 		if (!p)
2812 			goto out_resource;
2813 		*p++ = cpu_to_be32(255);
2814 	}
2815 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
2816 		p = xdr_reserve_space(xdr, 4);
2817 		if (!p)
2818 			goto out_resource;
2819 		*p++ = cpu_to_be32(statfs.f_namelen);
2820 	}
2821 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
2822 		p = xdr_reserve_space(xdr, 8);
2823 		if (!p)
2824 			goto out_resource;
2825 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
2826 	}
2827 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
2828 		p = xdr_reserve_space(xdr, 8);
2829 		if (!p)
2830 			goto out_resource;
2831 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
2832 	}
2833 	if (bmval1 & FATTR4_WORD1_MODE) {
2834 		p = xdr_reserve_space(xdr, 4);
2835 		if (!p)
2836 			goto out_resource;
2837 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
2838 	}
2839 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
2840 		p = xdr_reserve_space(xdr, 4);
2841 		if (!p)
2842 			goto out_resource;
2843 		*p++ = cpu_to_be32(1);
2844 	}
2845 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
2846 		p = xdr_reserve_space(xdr, 4);
2847 		if (!p)
2848 			goto out_resource;
2849 		*p++ = cpu_to_be32(stat.nlink);
2850 	}
2851 	if (bmval1 & FATTR4_WORD1_OWNER) {
2852 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
2853 		if (status)
2854 			goto out;
2855 	}
2856 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
2857 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
2858 		if (status)
2859 			goto out;
2860 	}
2861 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
2862 		p = xdr_reserve_space(xdr, 8);
2863 		if (!p)
2864 			goto out_resource;
2865 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
2866 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
2867 	}
2868 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
2869 		p = xdr_reserve_space(xdr, 8);
2870 		if (!p)
2871 			goto out_resource;
2872 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
2873 		p = xdr_encode_hyper(p, dummy64);
2874 	}
2875 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
2876 		p = xdr_reserve_space(xdr, 8);
2877 		if (!p)
2878 			goto out_resource;
2879 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
2880 		p = xdr_encode_hyper(p, dummy64);
2881 	}
2882 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
2883 		p = xdr_reserve_space(xdr, 8);
2884 		if (!p)
2885 			goto out_resource;
2886 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
2887 		p = xdr_encode_hyper(p, dummy64);
2888 	}
2889 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
2890 		p = xdr_reserve_space(xdr, 8);
2891 		if (!p)
2892 			goto out_resource;
2893 		dummy64 = (u64)stat.blocks << 9;
2894 		p = xdr_encode_hyper(p, dummy64);
2895 	}
2896 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
2897 		p = xdr_reserve_space(xdr, 12);
2898 		if (!p)
2899 			goto out_resource;
2900 		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
2901 		*p++ = cpu_to_be32(stat.atime.tv_nsec);
2902 	}
2903 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
2904 		p = xdr_reserve_space(xdr, 12);
2905 		if (!p)
2906 			goto out_resource;
2907 		p = encode_time_delta(p, d_inode(dentry));
2908 	}
2909 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
2910 		p = xdr_reserve_space(xdr, 12);
2911 		if (!p)
2912 			goto out_resource;
2913 		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
2914 		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
2915 	}
2916 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
2917 		p = xdr_reserve_space(xdr, 12);
2918 		if (!p)
2919 			goto out_resource;
2920 		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
2921 		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
2922 	}
2923 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
2924 		struct kstat parent_stat;
2925 		u64 ino = stat.ino;
2926 
2927 		p = xdr_reserve_space(xdr, 8);
2928 		if (!p)
2929                 	goto out_resource;
2930 		/*
2931 		 * Get parent's attributes if not ignoring crossmount
2932 		 * and this is the root of a cross-mounted filesystem.
2933 		 */
2934 		if (ignore_crossmnt == 0 &&
2935 		    dentry == exp->ex_path.mnt->mnt_root) {
2936 			err = get_parent_attributes(exp, &parent_stat);
2937 			if (err)
2938 				goto out_nfserr;
2939 			ino = parent_stat.ino;
2940 		}
2941 		p = xdr_encode_hyper(p, ino);
2942 	}
2943 #ifdef CONFIG_NFSD_PNFS
2944 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
2945 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
2946 		if (status)
2947 			goto out;
2948 	}
2949 
2950 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
2951 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
2952 		if (status)
2953 			goto out;
2954 	}
2955 
2956 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
2957 		p = xdr_reserve_space(xdr, 4);
2958 		if (!p)
2959 			goto out_resource;
2960 		*p++ = cpu_to_be32(stat.blksize);
2961 	}
2962 #endif /* CONFIG_NFSD_PNFS */
2963 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
2964 		u32 supp[3];
2965 
2966 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2967 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
2968 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
2969 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
2970 
2971 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
2972 		if (status)
2973 			goto out;
2974 	}
2975 
2976 	if (bmval2 & FATTR4_WORD2_CHANGE_ATTR_TYPE) {
2977 		p = xdr_reserve_space(xdr, 4);
2978 		if (!p)
2979 			goto out_resource;
2980 		if (IS_I_VERSION(d_inode(dentry)))
2981 			*p++ = cpu_to_be32(NFS4_CHANGE_TYPE_IS_MONOTONIC_INCR);
2982 		else
2983 			*p++ = cpu_to_be32(NFS4_CHANGE_TYPE_IS_TIME_METADATA);
2984 	}
2985 
2986 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2987 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2988 		status = nfsd4_encode_security_label(xdr, rqstp, context,
2989 								contextlen);
2990 		if (status)
2991 			goto out;
2992 	}
2993 #endif
2994 
2995 	attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
2996 	write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
2997 	status = nfs_ok;
2998 
2999 out:
3000 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
3001 	if (context)
3002 		security_release_secctx(context, contextlen);
3003 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
3004 	kfree(acl);
3005 	if (tempfh) {
3006 		fh_put(tempfh);
3007 		kfree(tempfh);
3008 	}
3009 	if (status)
3010 		xdr_truncate_encode(xdr, starting_len);
3011 	return status;
3012 out_nfserr:
3013 	status = nfserrno(err);
3014 	goto out;
3015 out_resource:
3016 	status = nfserr_resource;
3017 	goto out;
3018 }
3019 
3020 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
3021 				struct xdr_buf *buf, __be32 *p, int bytes)
3022 {
3023 	xdr->scratch.iov_len = 0;
3024 	memset(buf, 0, sizeof(struct xdr_buf));
3025 	buf->head[0].iov_base = p;
3026 	buf->head[0].iov_len = 0;
3027 	buf->len = 0;
3028 	xdr->buf = buf;
3029 	xdr->iov = buf->head;
3030 	xdr->p = p;
3031 	xdr->end = (void *)p + bytes;
3032 	buf->buflen = bytes;
3033 }
3034 
3035 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
3036 			struct svc_fh *fhp, struct svc_export *exp,
3037 			struct dentry *dentry, u32 *bmval,
3038 			struct svc_rqst *rqstp, int ignore_crossmnt)
3039 {
3040 	struct xdr_buf dummy;
3041 	struct xdr_stream xdr;
3042 	__be32 ret;
3043 
3044 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
3045 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
3046 							ignore_crossmnt);
3047 	*p = xdr.p;
3048 	return ret;
3049 }
3050 
3051 static inline int attributes_need_mount(u32 *bmval)
3052 {
3053 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
3054 		return 1;
3055 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
3056 		return 1;
3057 	return 0;
3058 }
3059 
3060 static __be32
3061 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
3062 			const char *name, int namlen)
3063 {
3064 	struct svc_export *exp = cd->rd_fhp->fh_export;
3065 	struct dentry *dentry;
3066 	__be32 nfserr;
3067 	int ignore_crossmnt = 0;
3068 
3069 	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
3070 	if (IS_ERR(dentry))
3071 		return nfserrno(PTR_ERR(dentry));
3072 
3073 	exp_get(exp);
3074 	/*
3075 	 * In the case of a mountpoint, the client may be asking for
3076 	 * attributes that are only properties of the underlying filesystem
3077 	 * as opposed to the cross-mounted file system. In such a case,
3078 	 * we will not follow the cross mount and will fill the attribtutes
3079 	 * directly from the mountpoint dentry.
3080 	 */
3081 	if (nfsd_mountpoint(dentry, exp)) {
3082 		int err;
3083 
3084 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
3085 				&& !attributes_need_mount(cd->rd_bmval)) {
3086 			ignore_crossmnt = 1;
3087 			goto out_encode;
3088 		}
3089 		/*
3090 		 * Why the heck aren't we just using nfsd_lookup??
3091 		 * Different "."/".." handling?  Something else?
3092 		 * At least, add a comment here to explain....
3093 		 */
3094 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
3095 		if (err) {
3096 			nfserr = nfserrno(err);
3097 			goto out_put;
3098 		}
3099 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
3100 		if (nfserr)
3101 			goto out_put;
3102 
3103 	}
3104 out_encode:
3105 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
3106 					cd->rd_rqstp, ignore_crossmnt);
3107 out_put:
3108 	dput(dentry);
3109 	exp_put(exp);
3110 	return nfserr;
3111 }
3112 
3113 static __be32 *
3114 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3115 {
3116 	__be32 *p;
3117 
3118 	p = xdr_reserve_space(xdr, 20);
3119 	if (!p)
3120 		return NULL;
3121 	*p++ = htonl(2);
3122 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3123 	*p++ = htonl(0);			 /* bmval1 */
3124 
3125 	*p++ = htonl(4);     /* attribute length */
3126 	*p++ = nfserr;       /* no htonl */
3127 	return p;
3128 }
3129 
3130 static int
3131 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3132 		    loff_t offset, u64 ino, unsigned int d_type)
3133 {
3134 	struct readdir_cd *ccd = ccdv;
3135 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3136 	struct xdr_stream *xdr = cd->xdr;
3137 	int start_offset = xdr->buf->len;
3138 	int cookie_offset;
3139 	u32 name_and_cookie;
3140 	int entry_bytes;
3141 	__be32 nfserr = nfserr_toosmall;
3142 	__be64 wire_offset;
3143 	__be32 *p;
3144 
3145 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3146 	if (name && isdotent(name, namlen)) {
3147 		cd->common.err = nfs_ok;
3148 		return 0;
3149 	}
3150 
3151 	if (cd->cookie_offset) {
3152 		wire_offset = cpu_to_be64(offset);
3153 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3154 							&wire_offset, 8);
3155 	}
3156 
3157 	p = xdr_reserve_space(xdr, 4);
3158 	if (!p)
3159 		goto fail;
3160 	*p++ = xdr_one;                             /* mark entry present */
3161 	cookie_offset = xdr->buf->len;
3162 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3163 	if (!p)
3164 		goto fail;
3165 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
3166 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3167 
3168 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3169 	switch (nfserr) {
3170 	case nfs_ok:
3171 		break;
3172 	case nfserr_resource:
3173 		nfserr = nfserr_toosmall;
3174 		goto fail;
3175 	case nfserr_noent:
3176 		xdr_truncate_encode(xdr, start_offset);
3177 		goto skip_entry;
3178 	default:
3179 		/*
3180 		 * If the client requested the RDATTR_ERROR attribute,
3181 		 * we stuff the error code into this attribute
3182 		 * and continue.  If this attribute was not requested,
3183 		 * then in accordance with the spec, we fail the
3184 		 * entire READDIR operation(!)
3185 		 */
3186 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3187 			goto fail;
3188 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3189 		if (p == NULL) {
3190 			nfserr = nfserr_toosmall;
3191 			goto fail;
3192 		}
3193 	}
3194 	nfserr = nfserr_toosmall;
3195 	entry_bytes = xdr->buf->len - start_offset;
3196 	if (entry_bytes > cd->rd_maxcount)
3197 		goto fail;
3198 	cd->rd_maxcount -= entry_bytes;
3199 	/*
3200 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", so
3201 	 * let's always let through the first entry, at least:
3202 	 */
3203 	if (!cd->rd_dircount)
3204 		goto fail;
3205 	name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3206 	if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3207 		goto fail;
3208 	cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3209 
3210 	cd->cookie_offset = cookie_offset;
3211 skip_entry:
3212 	cd->common.err = nfs_ok;
3213 	return 0;
3214 fail:
3215 	xdr_truncate_encode(xdr, start_offset);
3216 	cd->common.err = nfserr;
3217 	return -EINVAL;
3218 }
3219 
3220 static __be32
3221 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3222 {
3223 	__be32 *p;
3224 
3225 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3226 	if (!p)
3227 		return nfserr_resource;
3228 	*p++ = cpu_to_be32(sid->si_generation);
3229 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3230 					sizeof(stateid_opaque_t));
3231 	return 0;
3232 }
3233 
3234 static __be32
3235 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
3236 {
3237 	struct xdr_stream *xdr = &resp->xdr;
3238 	__be32 *p;
3239 
3240 	p = xdr_reserve_space(xdr, 8);
3241 	if (!p)
3242 		return nfserr_resource;
3243 	*p++ = cpu_to_be32(access->ac_supported);
3244 	*p++ = cpu_to_be32(access->ac_resp_access);
3245 	return 0;
3246 }
3247 
3248 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
3249 {
3250 	struct xdr_stream *xdr = &resp->xdr;
3251 	__be32 *p;
3252 
3253 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3254 	if (!p)
3255 		return nfserr_resource;
3256 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3257 					NFS4_MAX_SESSIONID_LEN);
3258 	*p++ = cpu_to_be32(bcts->dir);
3259 	/* Upshifting from TCP to RDMA is not supported */
3260 	*p++ = cpu_to_be32(0);
3261 	return 0;
3262 }
3263 
3264 static __be32
3265 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
3266 {
3267 	struct xdr_stream *xdr = &resp->xdr;
3268 
3269 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3270 }
3271 
3272 
3273 static __be32
3274 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
3275 {
3276 	struct xdr_stream *xdr = &resp->xdr;
3277 	__be32 *p;
3278 
3279 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3280 	if (!p)
3281 		return nfserr_resource;
3282 	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
3283 						NFS4_VERIFIER_SIZE);
3284 	return 0;
3285 }
3286 
3287 static __be32
3288 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
3289 {
3290 	struct xdr_stream *xdr = &resp->xdr;
3291 	__be32 *p;
3292 
3293 	p = xdr_reserve_space(xdr, 20);
3294 	if (!p)
3295 		return nfserr_resource;
3296 	encode_cinfo(p, &create->cr_cinfo);
3297 	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3298 			create->cr_bmval[1], create->cr_bmval[2]);
3299 }
3300 
3301 static __be32
3302 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
3303 {
3304 	struct svc_fh *fhp = getattr->ga_fhp;
3305 	struct xdr_stream *xdr = &resp->xdr;
3306 
3307 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3308 				    getattr->ga_bmval, resp->rqstp, 0);
3309 }
3310 
3311 static __be32
3312 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
3313 {
3314 	struct xdr_stream *xdr = &resp->xdr;
3315 	struct svc_fh *fhp = *fhpp;
3316 	unsigned int len;
3317 	__be32 *p;
3318 
3319 	len = fhp->fh_handle.fh_size;
3320 	p = xdr_reserve_space(xdr, len + 4);
3321 	if (!p)
3322 		return nfserr_resource;
3323 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base, len);
3324 	return 0;
3325 }
3326 
3327 /*
3328 * Including all fields other than the name, a LOCK4denied structure requires
3329 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3330 */
3331 static __be32
3332 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3333 {
3334 	struct xdr_netobj *conf = &ld->ld_owner;
3335 	__be32 *p;
3336 
3337 again:
3338 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3339 	if (!p) {
3340 		/*
3341 		 * Don't fail to return the result just because we can't
3342 		 * return the conflicting open:
3343 		 */
3344 		if (conf->len) {
3345 			kfree(conf->data);
3346 			conf->len = 0;
3347 			conf->data = NULL;
3348 			goto again;
3349 		}
3350 		return nfserr_resource;
3351 	}
3352 	p = xdr_encode_hyper(p, ld->ld_start);
3353 	p = xdr_encode_hyper(p, ld->ld_length);
3354 	*p++ = cpu_to_be32(ld->ld_type);
3355 	if (conf->len) {
3356 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3357 		p = xdr_encode_opaque(p, conf->data, conf->len);
3358 		kfree(conf->data);
3359 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3360 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3361 		*p++ = cpu_to_be32(0); /* length of owner name */
3362 	}
3363 	return nfserr_denied;
3364 }
3365 
3366 static __be32
3367 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
3368 {
3369 	struct xdr_stream *xdr = &resp->xdr;
3370 
3371 	if (!nfserr)
3372 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3373 	else if (nfserr == nfserr_denied)
3374 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3375 
3376 	return nfserr;
3377 }
3378 
3379 static __be32
3380 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
3381 {
3382 	struct xdr_stream *xdr = &resp->xdr;
3383 
3384 	if (nfserr == nfserr_denied)
3385 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3386 	return nfserr;
3387 }
3388 
3389 static __be32
3390 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
3391 {
3392 	struct xdr_stream *xdr = &resp->xdr;
3393 
3394 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3395 }
3396 
3397 
3398 static __be32
3399 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
3400 {
3401 	struct xdr_stream *xdr = &resp->xdr;
3402 	__be32 *p;
3403 
3404 	p = xdr_reserve_space(xdr, 20);
3405 	if (!p)
3406 		return nfserr_resource;
3407 	p = encode_cinfo(p, &link->li_cinfo);
3408 	return 0;
3409 }
3410 
3411 
3412 static __be32
3413 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
3414 {
3415 	struct xdr_stream *xdr = &resp->xdr;
3416 	__be32 *p;
3417 
3418 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3419 	if (nfserr)
3420 		return nfserr;
3421 	p = xdr_reserve_space(xdr, 24);
3422 	if (!p)
3423 		return nfserr_resource;
3424 	p = encode_cinfo(p, &open->op_cinfo);
3425 	*p++ = cpu_to_be32(open->op_rflags);
3426 
3427 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3428 					open->op_bmval[2]);
3429 	if (nfserr)
3430 		return nfserr;
3431 
3432 	p = xdr_reserve_space(xdr, 4);
3433 	if (!p)
3434 		return nfserr_resource;
3435 
3436 	*p++ = cpu_to_be32(open->op_delegate_type);
3437 	switch (open->op_delegate_type) {
3438 	case NFS4_OPEN_DELEGATE_NONE:
3439 		break;
3440 	case NFS4_OPEN_DELEGATE_READ:
3441 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3442 		if (nfserr)
3443 			return nfserr;
3444 		p = xdr_reserve_space(xdr, 20);
3445 		if (!p)
3446 			return nfserr_resource;
3447 		*p++ = cpu_to_be32(open->op_recall);
3448 
3449 		/*
3450 		 * TODO: ACE's in delegations
3451 		 */
3452 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3453 		*p++ = cpu_to_be32(0);
3454 		*p++ = cpu_to_be32(0);
3455 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3456 		break;
3457 	case NFS4_OPEN_DELEGATE_WRITE:
3458 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3459 		if (nfserr)
3460 			return nfserr;
3461 		p = xdr_reserve_space(xdr, 32);
3462 		if (!p)
3463 			return nfserr_resource;
3464 		*p++ = cpu_to_be32(0);
3465 
3466 		/*
3467 		 * TODO: space_limit's in delegations
3468 		 */
3469 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3470 		*p++ = cpu_to_be32(~(u32)0);
3471 		*p++ = cpu_to_be32(~(u32)0);
3472 
3473 		/*
3474 		 * TODO: ACE's in delegations
3475 		 */
3476 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3477 		*p++ = cpu_to_be32(0);
3478 		*p++ = cpu_to_be32(0);
3479 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3480 		break;
3481 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
3482 		switch (open->op_why_no_deleg) {
3483 		case WND4_CONTENTION:
3484 		case WND4_RESOURCE:
3485 			p = xdr_reserve_space(xdr, 8);
3486 			if (!p)
3487 				return nfserr_resource;
3488 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3489 			/* deleg signaling not supported yet: */
3490 			*p++ = cpu_to_be32(0);
3491 			break;
3492 		default:
3493 			p = xdr_reserve_space(xdr, 4);
3494 			if (!p)
3495 				return nfserr_resource;
3496 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3497 		}
3498 		break;
3499 	default:
3500 		BUG();
3501 	}
3502 	/* XXX save filehandle here */
3503 	return 0;
3504 }
3505 
3506 static __be32
3507 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
3508 {
3509 	struct xdr_stream *xdr = &resp->xdr;
3510 
3511 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
3512 }
3513 
3514 static __be32
3515 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
3516 {
3517 	struct xdr_stream *xdr = &resp->xdr;
3518 
3519 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
3520 }
3521 
3522 static __be32 nfsd4_encode_splice_read(
3523 				struct nfsd4_compoundres *resp,
3524 				struct nfsd4_read *read,
3525 				struct file *file, unsigned long maxcount)
3526 {
3527 	struct xdr_stream *xdr = &resp->xdr;
3528 	struct xdr_buf *buf = xdr->buf;
3529 	u32 eof;
3530 	int space_left;
3531 	__be32 nfserr;
3532 	__be32 *p = xdr->p - 2;
3533 
3534 	/* Make sure there will be room for padding if needed */
3535 	if (xdr->end - xdr->p < 1)
3536 		return nfserr_resource;
3537 
3538 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
3539 				  file, read->rd_offset, &maxcount, &eof);
3540 	read->rd_length = maxcount;
3541 	if (nfserr) {
3542 		/*
3543 		 * nfsd_splice_actor may have already messed with the
3544 		 * page length; reset it so as not to confuse
3545 		 * xdr_truncate_encode:
3546 		 */
3547 		buf->page_len = 0;
3548 		return nfserr;
3549 	}
3550 
3551 	*(p++) = htonl(eof);
3552 	*(p++) = htonl(maxcount);
3553 
3554 	buf->page_len = maxcount;
3555 	buf->len += maxcount;
3556 	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
3557 							/ PAGE_SIZE;
3558 
3559 	/* Use rest of head for padding and remaining ops: */
3560 	buf->tail[0].iov_base = xdr->p;
3561 	buf->tail[0].iov_len = 0;
3562 	xdr->iov = buf->tail;
3563 	if (maxcount&3) {
3564 		int pad = 4 - (maxcount&3);
3565 
3566 		*(xdr->p++) = 0;
3567 
3568 		buf->tail[0].iov_base += maxcount&3;
3569 		buf->tail[0].iov_len = pad;
3570 		buf->len += pad;
3571 	}
3572 
3573 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
3574 				buf->buflen - buf->len);
3575 	buf->buflen = buf->len + space_left;
3576 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
3577 
3578 	return 0;
3579 }
3580 
3581 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
3582 				 struct nfsd4_read *read,
3583 				 struct file *file, unsigned long maxcount)
3584 {
3585 	struct xdr_stream *xdr = &resp->xdr;
3586 	u32 eof;
3587 	int v;
3588 	int starting_len = xdr->buf->len - 8;
3589 	long len;
3590 	int thislen;
3591 	__be32 nfserr;
3592 	__be32 tmp;
3593 	__be32 *p;
3594 	int pad;
3595 
3596 	/*
3597 	 * svcrdma requires every READ payload to start somewhere
3598 	 * in xdr->pages.
3599 	 */
3600 	if (xdr->iov == xdr->buf->head) {
3601 		xdr->iov = NULL;
3602 		xdr->end = xdr->p;
3603 	}
3604 
3605 	len = maxcount;
3606 	v = 0;
3607 	while (len) {
3608 		thislen = min_t(long, len, PAGE_SIZE);
3609 		p = xdr_reserve_space(xdr, thislen);
3610 		WARN_ON_ONCE(!p);
3611 		resp->rqstp->rq_vec[v].iov_base = p;
3612 		resp->rqstp->rq_vec[v].iov_len = thislen;
3613 		v++;
3614 		len -= thislen;
3615 	}
3616 	read->rd_vlen = v;
3617 
3618 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
3619 			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
3620 			    &eof);
3621 	read->rd_length = maxcount;
3622 	if (nfserr)
3623 		return nfserr;
3624 	if (svc_encode_read_payload(resp->rqstp, starting_len + 8, maxcount))
3625 		return nfserr_io;
3626 	xdr_truncate_encode(xdr, starting_len + 8 + xdr_align_size(maxcount));
3627 
3628 	tmp = htonl(eof);
3629 	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
3630 	tmp = htonl(maxcount);
3631 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
3632 
3633 	tmp = xdr_zero;
3634 	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
3635 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
3636 								&tmp, pad);
3637 	return 0;
3638 
3639 }
3640 
3641 static __be32
3642 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
3643 		  struct nfsd4_read *read)
3644 {
3645 	unsigned long maxcount;
3646 	struct xdr_stream *xdr = &resp->xdr;
3647 	struct file *file;
3648 	int starting_len = xdr->buf->len;
3649 	__be32 *p;
3650 
3651 	if (nfserr)
3652 		return nfserr;
3653 	file = read->rd_nf->nf_file;
3654 
3655 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
3656 	if (!p) {
3657 		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
3658 		return nfserr_resource;
3659 	}
3660 	if (resp->xdr.buf->page_len &&
3661 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
3662 		WARN_ON_ONCE(1);
3663 		return nfserr_resource;
3664 	}
3665 	xdr_commit_encode(xdr);
3666 
3667 	maxcount = svc_max_payload(resp->rqstp);
3668 	maxcount = min_t(unsigned long, maxcount,
3669 			 (xdr->buf->buflen - xdr->buf->len));
3670 	maxcount = min_t(unsigned long, maxcount, read->rd_length);
3671 
3672 	if (file->f_op->splice_read &&
3673 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
3674 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
3675 	else
3676 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
3677 
3678 	if (nfserr)
3679 		xdr_truncate_encode(xdr, starting_len);
3680 
3681 	return nfserr;
3682 }
3683 
3684 static __be32
3685 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
3686 {
3687 	int maxcount;
3688 	__be32 wire_count;
3689 	int zero = 0;
3690 	struct xdr_stream *xdr = &resp->xdr;
3691 	int length_offset = xdr->buf->len;
3692 	__be32 *p;
3693 
3694 	p = xdr_reserve_space(xdr, 4);
3695 	if (!p)
3696 		return nfserr_resource;
3697 	maxcount = PAGE_SIZE;
3698 
3699 	p = xdr_reserve_space(xdr, maxcount);
3700 	if (!p)
3701 		return nfserr_resource;
3702 	/*
3703 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
3704 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
3705 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
3706 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
3707 	 */
3708 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
3709 						(char *)p, &maxcount);
3710 	if (nfserr == nfserr_isdir)
3711 		nfserr = nfserr_inval;
3712 	if (nfserr) {
3713 		xdr_truncate_encode(xdr, length_offset);
3714 		return nfserr;
3715 	}
3716 
3717 	wire_count = htonl(maxcount);
3718 	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
3719 	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
3720 	if (maxcount & 3)
3721 		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
3722 						&zero, 4 - (maxcount&3));
3723 	return 0;
3724 }
3725 
3726 static __be32
3727 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
3728 {
3729 	int maxcount;
3730 	int bytes_left;
3731 	loff_t offset;
3732 	__be64 wire_offset;
3733 	struct xdr_stream *xdr = &resp->xdr;
3734 	int starting_len = xdr->buf->len;
3735 	__be32 *p;
3736 
3737 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3738 	if (!p)
3739 		return nfserr_resource;
3740 
3741 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
3742 	*p++ = cpu_to_be32(0);
3743 	*p++ = cpu_to_be32(0);
3744 	resp->xdr.buf->head[0].iov_len = ((char *)resp->xdr.p)
3745 				- (char *)resp->xdr.buf->head[0].iov_base;
3746 
3747 	/*
3748 	 * Number of bytes left for directory entries allowing for the
3749 	 * final 8 bytes of the readdir and a following failed op:
3750 	 */
3751 	bytes_left = xdr->buf->buflen - xdr->buf->len
3752 			- COMPOUND_ERR_SLACK_SPACE - 8;
3753 	if (bytes_left < 0) {
3754 		nfserr = nfserr_resource;
3755 		goto err_no_verf;
3756 	}
3757 	maxcount = svc_max_payload(resp->rqstp);
3758 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
3759 	/*
3760 	 * Note the rfc defines rd_maxcount as the size of the
3761 	 * READDIR4resok structure, which includes the verifier above
3762 	 * and the 8 bytes encoded at the end of this function:
3763 	 */
3764 	if (maxcount < 16) {
3765 		nfserr = nfserr_toosmall;
3766 		goto err_no_verf;
3767 	}
3768 	maxcount = min_t(int, maxcount-16, bytes_left);
3769 
3770 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
3771 	if (!readdir->rd_dircount)
3772 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
3773 
3774 	readdir->xdr = xdr;
3775 	readdir->rd_maxcount = maxcount;
3776 	readdir->common.err = 0;
3777 	readdir->cookie_offset = 0;
3778 
3779 	offset = readdir->rd_cookie;
3780 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
3781 			      &offset,
3782 			      &readdir->common, nfsd4_encode_dirent);
3783 	if (nfserr == nfs_ok &&
3784 	    readdir->common.err == nfserr_toosmall &&
3785 	    xdr->buf->len == starting_len + 8) {
3786 		/* nothing encoded; which limit did we hit?: */
3787 		if (maxcount - 16 < bytes_left)
3788 			/* It was the fault of rd_maxcount: */
3789 			nfserr = nfserr_toosmall;
3790 		else
3791 			/* We ran out of buffer space: */
3792 			nfserr = nfserr_resource;
3793 	}
3794 	if (nfserr)
3795 		goto err_no_verf;
3796 
3797 	if (readdir->cookie_offset) {
3798 		wire_offset = cpu_to_be64(offset);
3799 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
3800 							&wire_offset, 8);
3801 	}
3802 
3803 	p = xdr_reserve_space(xdr, 8);
3804 	if (!p) {
3805 		WARN_ON_ONCE(1);
3806 		goto err_no_verf;
3807 	}
3808 	*p++ = 0;	/* no more entries */
3809 	*p++ = htonl(readdir->common.err == nfserr_eof);
3810 
3811 	return 0;
3812 err_no_verf:
3813 	xdr_truncate_encode(xdr, starting_len);
3814 	return nfserr;
3815 }
3816 
3817 static __be32
3818 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
3819 {
3820 	struct xdr_stream *xdr = &resp->xdr;
3821 	__be32 *p;
3822 
3823 	p = xdr_reserve_space(xdr, 20);
3824 	if (!p)
3825 		return nfserr_resource;
3826 	p = encode_cinfo(p, &remove->rm_cinfo);
3827 	return 0;
3828 }
3829 
3830 static __be32
3831 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
3832 {
3833 	struct xdr_stream *xdr = &resp->xdr;
3834 	__be32 *p;
3835 
3836 	p = xdr_reserve_space(xdr, 40);
3837 	if (!p)
3838 		return nfserr_resource;
3839 	p = encode_cinfo(p, &rename->rn_sinfo);
3840 	p = encode_cinfo(p, &rename->rn_tinfo);
3841 	return 0;
3842 }
3843 
3844 static __be32
3845 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
3846 {
3847 	u32 i, nflavs, supported;
3848 	struct exp_flavor_info *flavs;
3849 	struct exp_flavor_info def_flavs[2];
3850 	__be32 *p, *flavorsp;
3851 	static bool report = true;
3852 
3853 	if (exp->ex_nflavors) {
3854 		flavs = exp->ex_flavors;
3855 		nflavs = exp->ex_nflavors;
3856 	} else { /* Handling of some defaults in absence of real secinfo: */
3857 		flavs = def_flavs;
3858 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
3859 			nflavs = 2;
3860 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
3861 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
3862 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
3863 			nflavs = 1;
3864 			flavs[0].pseudoflavor
3865 					= svcauth_gss_flavor(exp->ex_client);
3866 		} else {
3867 			nflavs = 1;
3868 			flavs[0].pseudoflavor
3869 					= exp->ex_client->flavour->flavour;
3870 		}
3871 	}
3872 
3873 	supported = 0;
3874 	p = xdr_reserve_space(xdr, 4);
3875 	if (!p)
3876 		return nfserr_resource;
3877 	flavorsp = p++;		/* to be backfilled later */
3878 
3879 	for (i = 0; i < nflavs; i++) {
3880 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
3881 		struct rpcsec_gss_info info;
3882 
3883 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
3884 			supported++;
3885 			p = xdr_reserve_space(xdr, 4 + 4 +
3886 					      XDR_LEN(info.oid.len) + 4 + 4);
3887 			if (!p)
3888 				return nfserr_resource;
3889 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
3890 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
3891 			*p++ = cpu_to_be32(info.qop);
3892 			*p++ = cpu_to_be32(info.service);
3893 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
3894 			supported++;
3895 			p = xdr_reserve_space(xdr, 4);
3896 			if (!p)
3897 				return nfserr_resource;
3898 			*p++ = cpu_to_be32(pf);
3899 		} else {
3900 			if (report)
3901 				pr_warn("NFS: SECINFO: security flavor %u "
3902 					"is not supported\n", pf);
3903 		}
3904 	}
3905 
3906 	if (nflavs != supported)
3907 		report = false;
3908 	*flavorsp = htonl(supported);
3909 	return 0;
3910 }
3911 
3912 static __be32
3913 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
3914 		     struct nfsd4_secinfo *secinfo)
3915 {
3916 	struct xdr_stream *xdr = &resp->xdr;
3917 
3918 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
3919 }
3920 
3921 static __be32
3922 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
3923 		     struct nfsd4_secinfo_no_name *secinfo)
3924 {
3925 	struct xdr_stream *xdr = &resp->xdr;
3926 
3927 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
3928 }
3929 
3930 /*
3931  * The SETATTR encode routine is special -- it always encodes a bitmap,
3932  * regardless of the error status.
3933  */
3934 static __be32
3935 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
3936 {
3937 	struct xdr_stream *xdr = &resp->xdr;
3938 	__be32 *p;
3939 
3940 	p = xdr_reserve_space(xdr, 16);
3941 	if (!p)
3942 		return nfserr_resource;
3943 	if (nfserr) {
3944 		*p++ = cpu_to_be32(3);
3945 		*p++ = cpu_to_be32(0);
3946 		*p++ = cpu_to_be32(0);
3947 		*p++ = cpu_to_be32(0);
3948 	}
3949 	else {
3950 		*p++ = cpu_to_be32(3);
3951 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
3952 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
3953 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
3954 	}
3955 	return nfserr;
3956 }
3957 
3958 static __be32
3959 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
3960 {
3961 	struct xdr_stream *xdr = &resp->xdr;
3962 	__be32 *p;
3963 
3964 	if (!nfserr) {
3965 		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
3966 		if (!p)
3967 			return nfserr_resource;
3968 		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
3969 		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
3970 						NFS4_VERIFIER_SIZE);
3971 	}
3972 	else if (nfserr == nfserr_clid_inuse) {
3973 		p = xdr_reserve_space(xdr, 8);
3974 		if (!p)
3975 			return nfserr_resource;
3976 		*p++ = cpu_to_be32(0);
3977 		*p++ = cpu_to_be32(0);
3978 	}
3979 	return nfserr;
3980 }
3981 
3982 static __be32
3983 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
3984 {
3985 	struct xdr_stream *xdr = &resp->xdr;
3986 	__be32 *p;
3987 
3988 	p = xdr_reserve_space(xdr, 16);
3989 	if (!p)
3990 		return nfserr_resource;
3991 	*p++ = cpu_to_be32(write->wr_bytes_written);
3992 	*p++ = cpu_to_be32(write->wr_how_written);
3993 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
3994 						NFS4_VERIFIER_SIZE);
3995 	return 0;
3996 }
3997 
3998 static __be32
3999 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
4000 			 struct nfsd4_exchange_id *exid)
4001 {
4002 	struct xdr_stream *xdr = &resp->xdr;
4003 	__be32 *p;
4004 	char *major_id;
4005 	char *server_scope;
4006 	int major_id_sz;
4007 	int server_scope_sz;
4008 	uint64_t minor_id = 0;
4009 	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
4010 
4011 	major_id = nn->nfsd_name;
4012 	major_id_sz = strlen(nn->nfsd_name);
4013 	server_scope = nn->nfsd_name;
4014 	server_scope_sz = strlen(nn->nfsd_name);
4015 
4016 	p = xdr_reserve_space(xdr,
4017 		8 /* eir_clientid */ +
4018 		4 /* eir_sequenceid */ +
4019 		4 /* eir_flags */ +
4020 		4 /* spr_how */);
4021 	if (!p)
4022 		return nfserr_resource;
4023 
4024 	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
4025 	*p++ = cpu_to_be32(exid->seqid);
4026 	*p++ = cpu_to_be32(exid->flags);
4027 
4028 	*p++ = cpu_to_be32(exid->spa_how);
4029 
4030 	switch (exid->spa_how) {
4031 	case SP4_NONE:
4032 		break;
4033 	case SP4_MACH_CRED:
4034 		/* spo_must_enforce bitmap: */
4035 		nfserr = nfsd4_encode_bitmap(xdr,
4036 					exid->spo_must_enforce[0],
4037 					exid->spo_must_enforce[1],
4038 					exid->spo_must_enforce[2]);
4039 		if (nfserr)
4040 			return nfserr;
4041 		/* spo_must_allow bitmap: */
4042 		nfserr = nfsd4_encode_bitmap(xdr,
4043 					exid->spo_must_allow[0],
4044 					exid->spo_must_allow[1],
4045 					exid->spo_must_allow[2]);
4046 		if (nfserr)
4047 			return nfserr;
4048 		break;
4049 	default:
4050 		WARN_ON_ONCE(1);
4051 	}
4052 
4053 	p = xdr_reserve_space(xdr,
4054 		8 /* so_minor_id */ +
4055 		4 /* so_major_id.len */ +
4056 		(XDR_QUADLEN(major_id_sz) * 4) +
4057 		4 /* eir_server_scope.len */ +
4058 		(XDR_QUADLEN(server_scope_sz) * 4) +
4059 		4 /* eir_server_impl_id.count (0) */);
4060 	if (!p)
4061 		return nfserr_resource;
4062 
4063 	/* The server_owner struct */
4064 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
4065 	/* major id */
4066 	p = xdr_encode_opaque(p, major_id, major_id_sz);
4067 
4068 	/* Server scope */
4069 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
4070 
4071 	/* Implementation id */
4072 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
4073 	return 0;
4074 }
4075 
4076 static __be32
4077 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
4078 			    struct nfsd4_create_session *sess)
4079 {
4080 	struct xdr_stream *xdr = &resp->xdr;
4081 	__be32 *p;
4082 
4083 	p = xdr_reserve_space(xdr, 24);
4084 	if (!p)
4085 		return nfserr_resource;
4086 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
4087 					NFS4_MAX_SESSIONID_LEN);
4088 	*p++ = cpu_to_be32(sess->seqid);
4089 	*p++ = cpu_to_be32(sess->flags);
4090 
4091 	p = xdr_reserve_space(xdr, 28);
4092 	if (!p)
4093 		return nfserr_resource;
4094 	*p++ = cpu_to_be32(0); /* headerpadsz */
4095 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
4096 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
4097 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
4098 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4099 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4100 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4101 
4102 	if (sess->fore_channel.nr_rdma_attrs) {
4103 		p = xdr_reserve_space(xdr, 4);
4104 		if (!p)
4105 			return nfserr_resource;
4106 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4107 	}
4108 
4109 	p = xdr_reserve_space(xdr, 28);
4110 	if (!p)
4111 		return nfserr_resource;
4112 	*p++ = cpu_to_be32(0); /* headerpadsz */
4113 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4114 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4115 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4116 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4117 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4118 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4119 
4120 	if (sess->back_channel.nr_rdma_attrs) {
4121 		p = xdr_reserve_space(xdr, 4);
4122 		if (!p)
4123 			return nfserr_resource;
4124 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4125 	}
4126 	return 0;
4127 }
4128 
4129 static __be32
4130 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4131 		      struct nfsd4_sequence *seq)
4132 {
4133 	struct xdr_stream *xdr = &resp->xdr;
4134 	__be32 *p;
4135 
4136 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4137 	if (!p)
4138 		return nfserr_resource;
4139 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4140 					NFS4_MAX_SESSIONID_LEN);
4141 	*p++ = cpu_to_be32(seq->seqid);
4142 	*p++ = cpu_to_be32(seq->slotid);
4143 	/* Note slotid's are numbered from zero: */
4144 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4145 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4146 	*p++ = cpu_to_be32(seq->status_flags);
4147 
4148 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4149 	return 0;
4150 }
4151 
4152 static __be32
4153 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4154 			  struct nfsd4_test_stateid *test_stateid)
4155 {
4156 	struct xdr_stream *xdr = &resp->xdr;
4157 	struct nfsd4_test_stateid_id *stateid, *next;
4158 	__be32 *p;
4159 
4160 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4161 	if (!p)
4162 		return nfserr_resource;
4163 	*p++ = htonl(test_stateid->ts_num_ids);
4164 
4165 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4166 		*p++ = stateid->ts_id_status;
4167 	}
4168 
4169 	return 0;
4170 }
4171 
4172 #ifdef CONFIG_NFSD_PNFS
4173 static __be32
4174 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4175 		struct nfsd4_getdeviceinfo *gdev)
4176 {
4177 	struct xdr_stream *xdr = &resp->xdr;
4178 	const struct nfsd4_layout_ops *ops;
4179 	u32 starting_len = xdr->buf->len, needed_len;
4180 	__be32 *p;
4181 
4182 	p = xdr_reserve_space(xdr, 4);
4183 	if (!p)
4184 		return nfserr_resource;
4185 
4186 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4187 
4188 	/* If maxcount is 0 then just update notifications */
4189 	if (gdev->gd_maxcount != 0) {
4190 		ops = nfsd4_layout_ops[gdev->gd_layout_type];
4191 		nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4192 		if (nfserr) {
4193 			/*
4194 			 * We don't bother to burden the layout drivers with
4195 			 * enforcing gd_maxcount, just tell the client to
4196 			 * come back with a bigger buffer if it's not enough.
4197 			 */
4198 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
4199 				goto toosmall;
4200 			return nfserr;
4201 		}
4202 	}
4203 
4204 	if (gdev->gd_notify_types) {
4205 		p = xdr_reserve_space(xdr, 4 + 4);
4206 		if (!p)
4207 			return nfserr_resource;
4208 		*p++ = cpu_to_be32(1);			/* bitmap length */
4209 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4210 	} else {
4211 		p = xdr_reserve_space(xdr, 4);
4212 		if (!p)
4213 			return nfserr_resource;
4214 		*p++ = 0;
4215 	}
4216 
4217 	return 0;
4218 toosmall:
4219 	dprintk("%s: maxcount too small\n", __func__);
4220 	needed_len = xdr->buf->len + 4 /* notifications */;
4221 	xdr_truncate_encode(xdr, starting_len);
4222 	p = xdr_reserve_space(xdr, 4);
4223 	if (!p)
4224 		return nfserr_resource;
4225 	*p++ = cpu_to_be32(needed_len);
4226 	return nfserr_toosmall;
4227 }
4228 
4229 static __be32
4230 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4231 		struct nfsd4_layoutget *lgp)
4232 {
4233 	struct xdr_stream *xdr = &resp->xdr;
4234 	const struct nfsd4_layout_ops *ops;
4235 	__be32 *p;
4236 
4237 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4238 	if (!p)
4239 		return nfserr_resource;
4240 
4241 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4242 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4243 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4244 				    sizeof(stateid_opaque_t));
4245 
4246 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4247 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4248 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4249 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4250 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4251 
4252 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4253 	return ops->encode_layoutget(xdr, lgp);
4254 }
4255 
4256 static __be32
4257 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4258 			  struct nfsd4_layoutcommit *lcp)
4259 {
4260 	struct xdr_stream *xdr = &resp->xdr;
4261 	__be32 *p;
4262 
4263 	p = xdr_reserve_space(xdr, 4);
4264 	if (!p)
4265 		return nfserr_resource;
4266 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4267 	if (lcp->lc_size_chg) {
4268 		p = xdr_reserve_space(xdr, 8);
4269 		if (!p)
4270 			return nfserr_resource;
4271 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4272 	}
4273 
4274 	return 0;
4275 }
4276 
4277 static __be32
4278 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4279 		struct nfsd4_layoutreturn *lrp)
4280 {
4281 	struct xdr_stream *xdr = &resp->xdr;
4282 	__be32 *p;
4283 
4284 	p = xdr_reserve_space(xdr, 4);
4285 	if (!p)
4286 		return nfserr_resource;
4287 	*p++ = cpu_to_be32(lrp->lrs_present);
4288 	if (lrp->lrs_present)
4289 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4290 	return 0;
4291 }
4292 #endif /* CONFIG_NFSD_PNFS */
4293 
4294 static __be32
4295 nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
4296 		struct nfsd42_write_res *write, bool sync)
4297 {
4298 	__be32 *p;
4299 	p = xdr_reserve_space(&resp->xdr, 4);
4300 	if (!p)
4301 		return nfserr_resource;
4302 
4303 	if (sync)
4304 		*p++ = cpu_to_be32(0);
4305 	else {
4306 		__be32 nfserr;
4307 		*p++ = cpu_to_be32(1);
4308 		nfserr = nfsd4_encode_stateid(&resp->xdr, &write->cb_stateid);
4309 		if (nfserr)
4310 			return nfserr;
4311 	}
4312 	p = xdr_reserve_space(&resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
4313 	if (!p)
4314 		return nfserr_resource;
4315 
4316 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4317 	*p++ = cpu_to_be32(write->wr_stable_how);
4318 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4319 				    NFS4_VERIFIER_SIZE);
4320 	return nfs_ok;
4321 }
4322 
4323 static __be32
4324 nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
4325 {
4326 	struct xdr_stream *xdr = &resp->xdr;
4327 	struct nfs42_netaddr *addr;
4328 	__be32 *p;
4329 
4330 	p = xdr_reserve_space(xdr, 4);
4331 	*p++ = cpu_to_be32(ns->nl4_type);
4332 
4333 	switch (ns->nl4_type) {
4334 	case NL4_NETADDR:
4335 		addr = &ns->u.nl4_addr;
4336 
4337 		/* netid_len, netid, uaddr_len, uaddr (port included
4338 		 * in RPCBIND_MAXUADDRLEN)
4339 		 */
4340 		p = xdr_reserve_space(xdr,
4341 			4 /* netid len */ +
4342 			(XDR_QUADLEN(addr->netid_len) * 4) +
4343 			4 /* uaddr len */ +
4344 			(XDR_QUADLEN(addr->addr_len) * 4));
4345 		if (!p)
4346 			return nfserr_resource;
4347 
4348 		*p++ = cpu_to_be32(addr->netid_len);
4349 		p = xdr_encode_opaque_fixed(p, addr->netid,
4350 					    addr->netid_len);
4351 		*p++ = cpu_to_be32(addr->addr_len);
4352 		p = xdr_encode_opaque_fixed(p, addr->addr,
4353 					addr->addr_len);
4354 		break;
4355 	default:
4356 		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
4357 		return nfserr_inval;
4358 	}
4359 
4360 	return 0;
4361 }
4362 
4363 static __be32
4364 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4365 		  struct nfsd4_copy *copy)
4366 {
4367 	__be32 *p;
4368 
4369 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
4370 			copy->cp_synchronous);
4371 	if (nfserr)
4372 		return nfserr;
4373 
4374 	p = xdr_reserve_space(&resp->xdr, 4 + 4);
4375 	*p++ = xdr_one; /* cr_consecutive */
4376 	*p++ = cpu_to_be32(copy->cp_synchronous);
4377 	return 0;
4378 }
4379 
4380 static __be32
4381 nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
4382 			    struct nfsd4_offload_status *os)
4383 {
4384 	struct xdr_stream *xdr = &resp->xdr;
4385 	__be32 *p;
4386 
4387 	p = xdr_reserve_space(xdr, 8 + 4);
4388 	if (!p)
4389 		return nfserr_resource;
4390 	p = xdr_encode_hyper(p, os->count);
4391 	*p++ = cpu_to_be32(0);
4392 
4393 	return nfserr;
4394 }
4395 
4396 static __be32
4397 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
4398 			 struct nfsd4_copy_notify *cn)
4399 {
4400 	struct xdr_stream *xdr = &resp->xdr;
4401 	__be32 *p;
4402 
4403 	if (nfserr)
4404 		return nfserr;
4405 
4406 	/* 8 sec, 4 nsec */
4407 	p = xdr_reserve_space(xdr, 12);
4408 	if (!p)
4409 		return nfserr_resource;
4410 
4411 	/* cnr_lease_time */
4412 	p = xdr_encode_hyper(p, cn->cpn_sec);
4413 	*p++ = cpu_to_be32(cn->cpn_nsec);
4414 
4415 	/* cnr_stateid */
4416 	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
4417 	if (nfserr)
4418 		return nfserr;
4419 
4420 	/* cnr_src.nl_nsvr */
4421 	p = xdr_reserve_space(xdr, 4);
4422 	if (!p)
4423 		return nfserr_resource;
4424 
4425 	*p++ = cpu_to_be32(1);
4426 
4427 	return nfsd42_encode_nl4_server(resp, &cn->cpn_src);
4428 }
4429 
4430 static __be32
4431 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
4432 		  struct nfsd4_seek *seek)
4433 {
4434 	__be32 *p;
4435 
4436 	p = xdr_reserve_space(&resp->xdr, 4 + 8);
4437 	*p++ = cpu_to_be32(seek->seek_eof);
4438 	p = xdr_encode_hyper(p, seek->seek_pos);
4439 
4440 	return 0;
4441 }
4442 
4443 static __be32
4444 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
4445 {
4446 	return nfserr;
4447 }
4448 
4449 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
4450 
4451 /*
4452  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
4453  * since we don't need to filter out obsolete ops as this is
4454  * done in the decoding phase.
4455  */
4456 static const nfsd4_enc nfsd4_enc_ops[] = {
4457 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
4458 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
4459 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
4460 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
4461 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
4462 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
4463 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
4464 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
4465 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
4466 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
4467 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
4468 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
4469 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
4470 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
4471 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
4472 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
4473 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
4474 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
4475 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
4476 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
4477 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
4478 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
4479 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
4480 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
4481 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
4482 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
4483 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
4484 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
4485 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
4486 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
4487 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
4488 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
4489 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
4490 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
4491 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
4492 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
4493 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
4494 
4495 	/* NFSv4.1 operations */
4496 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
4497 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
4498 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
4499 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
4500 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
4501 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
4502 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
4503 #ifdef CONFIG_NFSD_PNFS
4504 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
4505 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
4506 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
4507 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
4508 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
4509 #else
4510 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
4511 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
4512 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
4513 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
4514 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
4515 #endif
4516 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
4517 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
4518 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
4519 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
4520 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
4521 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
4522 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
4523 
4524 	/* NFSv4.2 operations */
4525 	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
4526 	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
4527 	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_copy_notify,
4528 	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
4529 	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
4530 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
4531 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
4532 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
4533 	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_offload_status,
4534 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_noop,
4535 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
4536 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
4537 	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
4538 };
4539 
4540 /*
4541  * Calculate whether we still have space to encode repsize bytes.
4542  * There are two considerations:
4543  *     - For NFS versions >=4.1, the size of the reply must stay within
4544  *       session limits
4545  *     - For all NFS versions, we must stay within limited preallocated
4546  *       buffer space.
4547  *
4548  * This is called before the operation is processed, so can only provide
4549  * an upper estimate.  For some nonidempotent operations (such as
4550  * getattr), it's not necessarily a problem if that estimate is wrong,
4551  * as we can fail it after processing without significant side effects.
4552  */
4553 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
4554 {
4555 	struct xdr_buf *buf = &resp->rqstp->rq_res;
4556 	struct nfsd4_slot *slot = resp->cstate.slot;
4557 
4558 	if (buf->len + respsize <= buf->buflen)
4559 		return nfs_ok;
4560 	if (!nfsd4_has_session(&resp->cstate))
4561 		return nfserr_resource;
4562 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
4563 		WARN_ON_ONCE(1);
4564 		return nfserr_rep_too_big_to_cache;
4565 	}
4566 	return nfserr_rep_too_big;
4567 }
4568 
4569 void
4570 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
4571 {
4572 	struct xdr_stream *xdr = &resp->xdr;
4573 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
4574 	struct svc_rqst *rqstp = resp->rqstp;
4575 	const struct nfsd4_operation *opdesc = op->opdesc;
4576 	int post_err_offset;
4577 	nfsd4_enc encoder;
4578 	__be32 *p;
4579 
4580 	p = xdr_reserve_space(xdr, 8);
4581 	if (!p) {
4582 		WARN_ON_ONCE(1);
4583 		return;
4584 	}
4585 	*p++ = cpu_to_be32(op->opnum);
4586 	post_err_offset = xdr->buf->len;
4587 
4588 	if (op->opnum == OP_ILLEGAL)
4589 		goto status;
4590 	if (op->status && opdesc &&
4591 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
4592 		goto status;
4593 	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
4594 	       !nfsd4_enc_ops[op->opnum]);
4595 	encoder = nfsd4_enc_ops[op->opnum];
4596 	op->status = encoder(resp, op->status, &op->u);
4597 	if (opdesc && opdesc->op_release)
4598 		opdesc->op_release(&op->u);
4599 	xdr_commit_encode(xdr);
4600 
4601 	/* nfsd4_check_resp_size guarantees enough room for error status */
4602 	if (!op->status) {
4603 		int space_needed = 0;
4604 		if (!nfsd4_last_compound_op(rqstp))
4605 			space_needed = COMPOUND_ERR_SLACK_SPACE;
4606 		op->status = nfsd4_check_resp_size(resp, space_needed);
4607 	}
4608 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
4609 		struct nfsd4_slot *slot = resp->cstate.slot;
4610 
4611 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
4612 			op->status = nfserr_rep_too_big_to_cache;
4613 		else
4614 			op->status = nfserr_rep_too_big;
4615 	}
4616 	if (op->status == nfserr_resource ||
4617 	    op->status == nfserr_rep_too_big ||
4618 	    op->status == nfserr_rep_too_big_to_cache) {
4619 		/*
4620 		 * The operation may have already been encoded or
4621 		 * partially encoded.  No op returns anything additional
4622 		 * in the case of one of these three errors, so we can
4623 		 * just truncate back to after the status.  But it's a
4624 		 * bug if we had to do this on a non-idempotent op:
4625 		 */
4626 		warn_on_nonidempotent_op(op);
4627 		xdr_truncate_encode(xdr, post_err_offset);
4628 	}
4629 	if (so) {
4630 		int len = xdr->buf->len - post_err_offset;
4631 
4632 		so->so_replay.rp_status = op->status;
4633 		so->so_replay.rp_buflen = len;
4634 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
4635 						so->so_replay.rp_buf, len);
4636 	}
4637 status:
4638 	/* Note that op->status is already in network byte order: */
4639 	write_bytes_to_xdr_buf(xdr->buf, post_err_offset - 4, &op->status, 4);
4640 }
4641 
4642 /*
4643  * Encode the reply stored in the stateowner reply cache
4644  *
4645  * XDR note: do not encode rp->rp_buflen: the buffer contains the
4646  * previously sent already encoded operation.
4647  */
4648 void
4649 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
4650 {
4651 	__be32 *p;
4652 	struct nfs4_replay *rp = op->replay;
4653 
4654 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
4655 	if (!p) {
4656 		WARN_ON_ONCE(1);
4657 		return;
4658 	}
4659 	*p++ = cpu_to_be32(op->opnum);
4660 	*p++ = rp->rp_status;  /* already xdr'ed */
4661 
4662 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
4663 }
4664 
4665 int
4666 nfs4svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
4667 {
4668         return xdr_ressize_check(rqstp, p);
4669 }
4670 
4671 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
4672 {
4673 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
4674 
4675 	if (args->ops != args->iops) {
4676 		kfree(args->ops);
4677 		args->ops = args->iops;
4678 	}
4679 	kfree(args->tmpp);
4680 	args->tmpp = NULL;
4681 	while (args->to_free) {
4682 		struct svcxdr_tmpbuf *tb = args->to_free;
4683 		args->to_free = tb->next;
4684 		kfree(tb);
4685 	}
4686 }
4687 
4688 int
4689 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p)
4690 {
4691 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
4692 
4693 	if (rqstp->rq_arg.head[0].iov_len % 4) {
4694 		/* client is nuts */
4695 		dprintk("%s: compound not properly padded! (peeraddr=%pISc xid=0x%x)",
4696 			__func__, svc_addr(rqstp), be32_to_cpu(rqstp->rq_xid));
4697 		return 0;
4698 	}
4699 	args->p = p;
4700 	args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
4701 	args->pagelist = rqstp->rq_arg.pages;
4702 	args->pagelen = rqstp->rq_arg.page_len;
4703 	args->tail = false;
4704 	args->tmpp = NULL;
4705 	args->to_free = NULL;
4706 	args->ops = args->iops;
4707 	args->rqstp = rqstp;
4708 
4709 	return !nfsd4_decode_compound(args);
4710 }
4711 
4712 int
4713 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p)
4714 {
4715 	/*
4716 	 * All that remains is to write the tag and operation count...
4717 	 */
4718 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
4719 	struct xdr_buf *buf = resp->xdr.buf;
4720 
4721 	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
4722 				 buf->tail[0].iov_len);
4723 
4724 	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
4725 
4726 	p = resp->tagp;
4727 	*p++ = htonl(resp->taglen);
4728 	memcpy(p, resp->tag, resp->taglen);
4729 	p += XDR_QUADLEN(resp->taglen);
4730 	*p++ = htonl(resp->opcnt);
4731 
4732 	nfsd4_sequence_done(resp);
4733 	return 1;
4734 }
4735 
4736 /*
4737  * Local variables:
4738  *  c-basic-offset: 8
4739  * End:
4740  */
4741