Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 5533 insertions, 0 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
new file mode 100644
index 0000000000..92c7dde148
--- /dev/null
+++ b/fs/nfsd/nfs4xdr.c
@@ -0,0 +1,5533 @@
+/*
+ *  Server-side XDR for NFSv4
+ *
+ *  Copyright (c) 2002 The Regents of the University of Michigan.
+ *  All rights reserved.
+ *
+ *  Kendrick Smith <kmsmith@umich.edu>
+ *  Andy Adamson   <andros@umich.edu>
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions
+ *  are met:
+ *
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the University nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
+ *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/statfs.h>
+#include <linux/utsname.h>
+#include <linux/pagemap.h>
+#include <linux/sunrpc/svcauth_gss.h>
+#include <linux/sunrpc/addr.h>
+#include <linux/xattr.h>
+#include <linux/vmalloc.h>
+
+#include <uapi/linux/xattr.h>
+
+#include "idmap.h"
+#include "acl.h"
+#include "xdr4.h"
+#include "vfs.h"
+#include "state.h"
+#include "cache.h"
+#include "netns.h"
+#include "pnfs.h"
+#include "filecache.h"
+
+#include "trace.h"
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+#include <linux/security.h>
+#endif
+
+
+#define NFSDDBG_FACILITY		NFSDDBG_XDR
+
+const u32 nfsd_suppattrs[3][3] = {
+	{NFSD4_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
+
+	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
+	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
+	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
+};
+
+/*
+ * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
+ * directory in order to indicate to the client that a filesystem boundary is present
+ * We use a fixed fsid for a referral
+ */
+#define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
+#define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
+
+static __be32
+check_filename(char *str, int len)
+{
+	int i;
+
+	if (len == 0)
+		return nfserr_inval;
+	if (len > NFS4_MAXNAMLEN)
+		return nfserr_nametoolong;
+	if (isdotent(str, len))
+		return nfserr_badname;
+	for (i = 0; i < len; i++)
+		if (str[i] == '/')
+			return nfserr_badname;
+	return 0;
+}
+
+static int zero_clientid(clientid_t *clid)
+{
+	return (clid->cl_boot == 0) && (clid->cl_id == 0);
+}
+
+/**
+ * svcxdr_tmpalloc - allocate memory to be freed after compound processing
+ * @argp: NFSv4 compound argument structure
+ * @len: length of buffer to allocate
+ *
+ * Allocates a buffer of size @len to be freed when processing the compound
+ * operation described in @argp finishes.
+ */
+static void *
+svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
+{
+	struct svcxdr_tmpbuf *tb;
+
+	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
+	if (!tb)
+		return NULL;
+	tb->next = argp->to_free;
+	argp->to_free = tb;
+	return tb->buf;
+}
+
+/*
+ * For xdr strings that need to be passed to other kernel api's
+ * as null-terminated strings.
+ *
+ * Note null-terminating in place usually isn't safe since the
+ * buffer might end on a page boundary.
+ */
+static char *
+svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
+{
+	char *p = svcxdr_tmpalloc(argp, len + 1);
+
+	if (!p)
+		return NULL;
+	memcpy(p, buf, len);
+	p[len] = '\0';
+	return p;
+}
+
+static void *
+svcxdr_savemem(struct nfsd4_compoundargs *argp, __be32 *p, u32 len)
+{
+	__be32 *tmp;
+
+	/*
+	 * The location of the decoded data item is stable,
+	 * so @p is OK to use. This is the common case.
+	 */
+	if (p != argp->xdr->scratch.iov_base)
+		return p;
+
+	tmp = svcxdr_tmpalloc(argp, len);
+	if (!tmp)
+		return NULL;
+	memcpy(tmp, p, len);
+	return tmp;
+}
+
+/*
+ * NFSv4 basic data type decoders
+ */
+
+/*
+ * This helper handles variable-length opaques which belong to protocol
+ * elements that this implementation does not support.
+ */
+static __be32
+nfsd4_decode_ignored_string(struct nfsd4_compoundargs *argp, u32 maxlen)
+{
+	u32 len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	if (maxlen && len > maxlen)
+		return nfserr_bad_xdr;
+	if (!xdr_inline_decode(argp->xdr, len))
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
+{
+	__be32 *p;
+	u32 len;
+
+	if (xdr_stream_decode_u32(argp->xdr, &len) < 0)
+		return nfserr_bad_xdr;
+	if (len == 0 || len > NFS4_OPAQUE_LIMIT)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, len);
+	if (!p)
+		return nfserr_bad_xdr;
+	o->data = svcxdr_savemem(argp, p, len);
+	if (!o->data)
+		return nfserr_jukebox;
+	o->len = len;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_component4(struct nfsd4_compoundargs *argp, char **namp, u32 *lenp)
+{
+	__be32 *p, status;
+
+	if (xdr_stream_decode_u32(argp->xdr, lenp) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, *lenp);
+	if (!p)
+		return nfserr_bad_xdr;
+	status = check_filename((char *)p, *lenp);
+	if (status)
+		return status;
+	*namp = svcxdr_savemem(argp, p, *lenp);
+	if (!*namp)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfstime4(struct nfsd4_compoundargs *argp, struct timespec64 *tv)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 3);
+	if (!p)
+		return nfserr_bad_xdr;
+	p = xdr_decode_hyper(p, &tv->tv_sec);
+	tv->tv_nsec = be32_to_cpup(p++);
+	if (tv->tv_nsec >= (u32)1000000000)
+		return nfserr_inval;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_verifier4(struct nfsd4_compoundargs *argp, nfs4_verifier *verf)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(verf->data, p, sizeof(verf->data));
+	return nfs_ok;
+}
+
+/**
+ * nfsd4_decode_bitmap4 - Decode an NFSv4 bitmap4
+ * @argp: NFSv4 compound argument structure
+ * @bmval: pointer to an array of u32's to decode into
+ * @bmlen: size of the @bmval array
+ *
+ * The server needs to return nfs_ok rather than nfserr_bad_xdr when
+ * encountering bitmaps containing bits it does not recognize. This
+ * includes bits in bitmap words past WORDn, where WORDn is the last
+ * bitmap WORD the implementation currently supports. Thus we are
+ * careful here to simply ignore bits in bitmap words that this
+ * implementation has yet to support explicitly.
+ *
+ * Return values:
+ *   %nfs_ok: @bmval populated successfully
+ *   %nfserr_bad_xdr: the encoded bitmap was invalid
+ */
+static __be32
+nfsd4_decode_bitmap4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen)
+{
+	ssize_t status;
+
+	status = xdr_stream_decode_uint32_array(argp->xdr, bmval, bmlen);
+	return status == -EBADMSG ? nfserr_bad_xdr : nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfsace4(struct nfsd4_compoundargs *argp, struct nfs4_ace *ace)
+{
+	__be32 *p, status;
+	u32 length;
+
+	if (xdr_stream_decode_u32(argp->xdr, &ace->type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &ace->flag) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &ace->access_mask) < 0)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, length);
+	if (!p)
+		return nfserr_bad_xdr;
+	ace->whotype = nfs4_acl_get_whotype((char *)p, length);
+	if (ace->whotype != NFS4_ACL_WHO_NAMED)
+		status = nfs_ok;
+	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+		status = nfsd_map_name_to_gid(argp->rqstp,
+				(char *)p, length, &ace->who_gid);
+	else
+		status = nfsd_map_name_to_uid(argp->rqstp,
+				(char *)p, length, &ace->who_uid);
+
+	return status;
+}
+
+/* A counted array of nfsace4's */
+static noinline __be32
+nfsd4_decode_acl(struct nfsd4_compoundargs *argp, struct nfs4_acl **acl)
+{
+	struct nfs4_ace *ace;
+	__be32 status;
+	u32 count;
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+
+	if (count > xdr_stream_remaining(argp->xdr) / 20)
+		/*
+		 * Even with 4-byte names there wouldn't be
+		 * space for that many aces; something fishy is
+		 * going on:
+		 */
+		return nfserr_fbig;
+
+	*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(count));
+	if (*acl == NULL)
+		return nfserr_jukebox;
+
+	(*acl)->naces = count;
+	for (ace = (*acl)->aces; ace < (*acl)->aces + count; ace++) {
+		status = nfsd4_decode_nfsace4(argp, ace);
+		if (status)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+static noinline __be32
+nfsd4_decode_security_label(struct nfsd4_compoundargs *argp,
+			    struct xdr_netobj *label)
+{
+	u32 lfs, pi, length;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lfs) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &pi) < 0)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+		return nfserr_bad_xdr;
+	if (length > NFS4_MAXLABELLEN)
+		return nfserr_badlabel;
+	p = xdr_inline_decode(argp->xdr, length);
+	if (!p)
+		return nfserr_bad_xdr;
+	label->len = length;
+	label->data = svcxdr_dupstr(argp, p, length);
+	if (!label->data)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_fattr4(struct nfsd4_compoundargs *argp, u32 *bmval, u32 bmlen,
+		    struct iattr *iattr, struct nfs4_acl **acl,
+		    struct xdr_netobj *label, int *umask)
+{
+	unsigned int starting_pos;
+	u32 attrlist4_count;
+	__be32 *p, status;
+
+	iattr->ia_valid = 0;
+	status = nfsd4_decode_bitmap4(argp, bmval, bmlen);
+	if (status)
+		return nfserr_bad_xdr;
+
+	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
+	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
+	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
+		if (nfsd_attrs_supported(argp->minorversion, bmval))
+			return nfserr_inval;
+		return nfserr_attrnotsupp;
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &attrlist4_count) < 0)
+		return nfserr_bad_xdr;
+	starting_pos = xdr_stream_pos(argp->xdr);
+
+	if (bmval[0] & FATTR4_WORD0_SIZE) {
+		u64 size;
+
+		if (xdr_stream_decode_u64(argp->xdr, &size) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_size = size;
+		iattr->ia_valid |= ATTR_SIZE;
+	}
+	if (bmval[0] & FATTR4_WORD0_ACL) {
+		status = nfsd4_decode_acl(argp, acl);
+		if (status)
+			return status;
+	} else
+		*acl = NULL;
+	if (bmval[1] & FATTR4_WORD1_MODE) {
+		u32 mode;
+
+		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_mode = mode;
+		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
+		iattr->ia_valid |= ATTR_MODE;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER) {
+		u32 length;
+
+		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+			return nfserr_bad_xdr;
+		p = xdr_inline_decode(argp->xdr, length);
+		if (!p)
+			return nfserr_bad_xdr;
+		status = nfsd_map_name_to_uid(argp->rqstp, (char *)p, length,
+					      &iattr->ia_uid);
+		if (status)
+			return status;
+		iattr->ia_valid |= ATTR_UID;
+	}
+	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
+		u32 length;
+
+		if (xdr_stream_decode_u32(argp->xdr, &length) < 0)
+			return nfserr_bad_xdr;
+		p = xdr_inline_decode(argp->xdr, length);
+		if (!p)
+			return nfserr_bad_xdr;
+		status = nfsd_map_name_to_gid(argp->rqstp, (char *)p, length,
+					      &iattr->ia_gid);
+		if (status)
+			return status;
+		iattr->ia_valid |= ATTR_GID;
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_atime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_ATIME;
+			break;
+		default:
+			return nfserr_bad_xdr;
+		}
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_CREATE) {
+		struct timespec64 ts;
+
+		/* No Linux filesystem supports setting this attribute. */
+		bmval[1] &= ~FATTR4_WORD1_TIME_CREATE;
+		status = nfsd4_decode_nfstime4(argp, &ts);
+		if (status)
+			return status;
+	}
+	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
+		u32 set_it;
+
+		if (xdr_stream_decode_u32(argp->xdr, &set_it) < 0)
+			return nfserr_bad_xdr;
+		switch (set_it) {
+		case NFS4_SET_TO_CLIENT_TIME:
+			status = nfsd4_decode_nfstime4(argp, &iattr->ia_mtime);
+			if (status)
+				return status;
+			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
+			break;
+		case NFS4_SET_TO_SERVER_TIME:
+			iattr->ia_valid |= ATTR_MTIME;
+			break;
+		default:
+			return nfserr_bad_xdr;
+		}
+	}
+	label->len = 0;
+	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
+	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
+		status = nfsd4_decode_security_label(argp, label);
+		if (status)
+			return status;
+	}
+	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
+		u32 mode, mask;
+
+		if (!umask)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u32(argp->xdr, &mode) < 0)
+			return nfserr_bad_xdr;
+		iattr->ia_mode = mode & (S_IFMT | S_IALLUGO);
+		if (xdr_stream_decode_u32(argp->xdr, &mask) < 0)
+			return nfserr_bad_xdr;
+		*umask = mask & S_IRWXUGO;
+		iattr->ia_valid |= ATTR_MODE;
+	}
+
+	/* request sanity: did attrlist4 contain the expected number of words? */
+	if (attrlist4_count != xdr_stream_pos(argp->xdr) - starting_pos)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_stateid4(struct nfsd4_compoundargs *argp, stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_STATEID_SIZE);
+	if (!p)
+		return nfserr_bad_xdr;
+	sid->si_generation = be32_to_cpup(p++);
+	memcpy(&sid->si_opaque, p, sizeof(sid->si_opaque));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_clientid4(struct nfsd4_compoundargs *argp, clientid_t *clientid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, sizeof(__be64));
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(clientid, p, sizeof(*clientid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_owner4(struct nfsd4_compoundargs *argp,
+			  clientid_t *clientid, struct xdr_netobj *owner)
+{
+	__be32 status;
+
+	status = nfsd4_decode_clientid4(argp, clientid);
+	if (status)
+		return status;
+	return nfsd4_decode_opaque(argp, owner);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_decode_deviceid4(struct nfsd4_compoundargs *argp,
+		       struct nfsd4_deviceid *devid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_DEVICEID4_SIZE);
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(devid, p, sizeof(*devid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutupdate4(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_layoutcommit *lcp)
+{
+	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (lcp->lc_layout_type < LAYOUT_NFSV4_1_FILES)
+		return nfserr_bad_xdr;
+	if (lcp->lc_layout_type >= LAYOUT_TYPE_MAX)
+		return nfserr_bad_xdr;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_up_len) < 0)
+		return nfserr_bad_xdr;
+	if (lcp->lc_up_len > 0) {
+		lcp->lc_up_layout = xdr_inline_decode(argp->xdr, lcp->lc_up_len);
+		if (!lcp->lc_up_layout)
+			return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutreturn4(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_layoutreturn *lrp)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_return_type) < 0)
+		return nfserr_bad_xdr;
+	switch (lrp->lr_return_type) {
+	case RETURN_FILE:
+		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.offset) < 0)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u64(argp->xdr, &lrp->lr_seg.length) < 0)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_stateid4(argp, &lrp->lr_sid);
+		if (status)
+			return status;
+		if (xdr_stream_decode_u32(argp->xdr, &lrp->lrf_body_len) < 0)
+			return nfserr_bad_xdr;
+		if (lrp->lrf_body_len > 0) {
+			lrp->lrf_body = xdr_inline_decode(argp->xdr, lrp->lrf_body_len);
+			if (!lrp->lrf_body)
+				return nfserr_bad_xdr;
+		}
+		break;
+	case RETURN_FSID:
+	case RETURN_ALL:
+		lrp->lr_seg.offset = 0;
+		lrp->lr_seg.length = NFS4_MAX_UINT64;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd4_decode_sessionid4(struct nfsd4_compoundargs *argp,
+			struct nfs4_sessionid *sessionid)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, NFS4_MAX_SESSIONID_LEN);
+	if (!p)
+		return nfserr_bad_xdr;
+	memcpy(sessionid->data, p, sizeof(sessionid->data));
+	return nfs_ok;
+}
+
+/* Defined in Appendix A of RFC 5531 */
+static __be32
+nfsd4_decode_authsys_parms(struct nfsd4_compoundargs *argp,
+			   struct nfsd4_cb_sec *cbs)
+{
+	u32 stamp, gidcount, uid, gid;
+	__be32 *p, status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &stamp) < 0)
+		return nfserr_bad_xdr;
+	/* machine name */
+	status = nfsd4_decode_ignored_string(argp, 255);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &uid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gidcount) < 0)
+		return nfserr_bad_xdr;
+	if (gidcount > 16)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, gidcount << 2);
+	if (!p)
+		return nfserr_bad_xdr;
+	if (cbs->flavor == (u32)(-1)) {
+		struct user_namespace *userns = nfsd_user_namespace(argp->rqstp);
+
+		kuid_t kuid = make_kuid(userns, uid);
+		kgid_t kgid = make_kgid(userns, gid);
+		if (uid_valid(kuid) && gid_valid(kgid)) {
+			cbs->uid = kuid;
+			cbs->gid = kgid;
+			cbs->flavor = RPC_AUTH_UNIX;
+		} else {
+			dprintk("RPC_AUTH_UNIX with invalid uid or gid, ignoring!\n");
+		}
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_gss_cb_handles4(struct nfsd4_compoundargs *argp,
+			     struct nfsd4_cb_sec *cbs)
+{
+	__be32 status;
+	u32 service;
+
+	dprintk("RPC_AUTH_GSS callback secflavor not supported!\n");
+
+	if (xdr_stream_decode_u32(argp->xdr, &service) < 0)
+		return nfserr_bad_xdr;
+	if (service < RPC_GSS_SVC_NONE || service > RPC_GSS_SVC_PRIVACY)
+		return nfserr_bad_xdr;
+	/* gcbp_handle_from_server */
+	status = nfsd4_decode_ignored_string(argp, 0);
+	if (status)
+		return status;
+	/* gcbp_handle_from_client */
+	status = nfsd4_decode_ignored_string(argp, 0);
+	if (status)
+		return status;
+
+	return nfs_ok;
+}
+
+/* a counted array of callback_sec_parms4 items */
+static __be32
+nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
+{
+	u32 i, secflavor, nr_secflavs;
+	__be32 status;
+
+	/* callback_sec_params4 */
+	if (xdr_stream_decode_u32(argp->xdr, &nr_secflavs) < 0)
+		return nfserr_bad_xdr;
+	if (nr_secflavs)
+		cbs->flavor = (u32)(-1);
+	else
+		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
+		cbs->flavor = 0;
+
+	for (i = 0; i < nr_secflavs; ++i) {
+		if (xdr_stream_decode_u32(argp->xdr, &secflavor) < 0)
+			return nfserr_bad_xdr;
+		switch (secflavor) {
+		case RPC_AUTH_NULL:
+			/* void */
+			if (cbs->flavor == (u32)(-1))
+				cbs->flavor = RPC_AUTH_NULL;
+			break;
+		case RPC_AUTH_UNIX:
+			status = nfsd4_decode_authsys_parms(argp, cbs);
+			if (status)
+				return status;
+			break;
+		case RPC_AUTH_GSS:
+			status = nfsd4_decode_gss_cb_handles4(argp, cbs);
+			if (status)
+				return status;
+			break;
+		default:
+			return nfserr_inval;
+		}
+	}
+
+	return nfs_ok;
+}
+
+
+/*
+ * NFSv4 operation argument decoders
+ */
+
+static __be32
+nfsd4_decode_access(struct nfsd4_compoundargs *argp,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	if (xdr_stream_decode_u32(argp->xdr, &access->ac_req_access) < 0)
+		return nfserr_bad_xdr;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_close(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	if (xdr_stream_decode_u32(argp->xdr, &close->cl_seqid) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_stateid4(argp, &close->cl_stateid);
+}
+
+
+static __be32
+nfsd4_decode_commit(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+	if (xdr_stream_decode_u64(argp->xdr, &commit->co_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &commit->co_count) < 0)
+		return nfserr_bad_xdr;
+	memset(&commit->co_verf, 0, sizeof(commit->co_verf));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_create(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	__be32 *p, status;
+
+	memset(create, 0, sizeof(*create));
+	if (xdr_stream_decode_u32(argp->xdr, &create->cr_type) < 0)
+		return nfserr_bad_xdr;
+	switch (create->cr_type) {
+	case NF4LNK:
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_datalen) < 0)
+			return nfserr_bad_xdr;
+		p = xdr_inline_decode(argp->xdr, create->cr_datalen);
+		if (!p)
+			return nfserr_bad_xdr;
+		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
+		if (!create->cr_data)
+			return nfserr_jukebox;
+		break;
+	case NF4BLK:
+	case NF4CHR:
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata1) < 0)
+			return nfserr_bad_xdr;
+		if (xdr_stream_decode_u32(argp->xdr, &create->cr_specdata2) < 0)
+			return nfserr_bad_xdr;
+		break;
+	case NF4SOCK:
+	case NF4FIFO:
+	case NF4DIR:
+	default:
+		break;
+	}
+	status = nfsd4_decode_component4(argp, &create->cr_name,
+					 &create->cr_namelen);
+	if (status)
+		return status;
+	status = nfsd4_decode_fattr4(argp, create->cr_bmval,
+				    ARRAY_SIZE(create->cr_bmval),
+				    &create->cr_iattr, &create->cr_acl,
+				    &create->cr_label, &create->cr_umask);
+	if (status)
+		return status;
+
+	return nfs_ok;
+}
+
+static inline __be32
+nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_delegreturn *dr = &u->delegreturn;
+	return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
+}
+
+static inline __be32
+nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	memset(getattr, 0, sizeof(*getattr));
+	return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
+				    ARRAY_SIZE(getattr->ga_bmval));
+}
+
+static __be32
+nfsd4_decode_link(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	memset(link, 0, sizeof(*link));
+	return nfsd4_decode_component4(argp, &link->li_name, &link->li_namelen);
+}
+
+static __be32
+nfsd4_decode_open_to_lock_owner4(struct nfsd4_compoundargs *argp,
+				 struct nfsd4_lock *lock)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_open_seqid) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lock->lk_new_open_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_new_lock_seqid) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_state_owner4(argp, &lock->lk_new_clientid,
+					 &lock->lk_new_owner);
+}
+
+static __be32
+nfsd4_decode_exist_lock_owner4(struct nfsd4_compoundargs *argp,
+			       struct nfsd4_lock *lock)
+{
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &lock->lk_old_lock_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_old_lock_seqid) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_locker4(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
+{
+	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_is_new) < 0)
+		return nfserr_bad_xdr;
+	if (lock->lk_is_new)
+		return nfsd4_decode_open_to_lock_owner4(argp, lock);
+	return nfsd4_decode_exist_lock_owner4(argp, lock);
+}
+
+static __be32
+nfsd4_decode_lock(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	memset(lock, 0, sizeof(*lock));
+	if (xdr_stream_decode_u32(argp->xdr, &lock->lk_type) < 0)
+		return nfserr_bad_xdr;
+	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &lock->lk_reclaim) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lock->lk_length) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_locker4(argp, lock);
+}
+
+static __be32
+nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	memset(lockt, 0, sizeof(*lockt));
+	if (xdr_stream_decode_u32(argp->xdr, &lockt->lt_type) < 0)
+		return nfserr_bad_xdr;
+	if ((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lockt->lt_length) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_state_owner4(argp, &lockt->lt_clientid,
+					 &lockt->lt_owner);
+}
+
+static __be32
+nfsd4_decode_locku(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_type) < 0)
+		return nfserr_bad_xdr;
+	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &locku->lu_seqid) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &locku->lu_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &locku->lu_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_lookup *lookup = &u->lookup;
+	return nfsd4_decode_component4(argp, &lookup->lo_name, &lookup->lo_len);
+}
+
+static __be32
+nfsd4_decode_createhow4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_createmode) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_createmode) {
+	case NFS4_CREATE_UNCHECKED:
+	case NFS4_CREATE_GUARDED:
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE:
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		break;
+	case NFS4_CREATE_EXCLUSIVE4_1:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_verifier4(argp, &open->op_verf);
+		if (status)
+			return status;
+		status = nfsd4_decode_fattr4(argp, open->op_bmval,
+					     ARRAY_SIZE(open->op_bmval),
+					     &open->op_iattr, &open->op_acl,
+					     &open->op_label, &open->op_umask);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_openflag4(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_create) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_create) {
+	case NFS4_OPEN_NOCREATE:
+		break;
+	case NFS4_OPEN_CREATE:
+		status = nfsd4_decode_createhow4(argp, open);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
+{
+	u32 w;
+
+	if (xdr_stream_decode_u32(argp->xdr, &w) < 0)
+		return nfserr_bad_xdr;
+	*share_access = w & NFS4_SHARE_ACCESS_MASK;
+	*deleg_want = w & NFS4_SHARE_WANT_MASK;
+	if (deleg_when)
+		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
+
+	switch (w & NFS4_SHARE_ACCESS_MASK) {
+	case NFS4_SHARE_ACCESS_READ:
+	case NFS4_SHARE_ACCESS_WRITE:
+	case NFS4_SHARE_ACCESS_BOTH:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_ACCESS_MASK;
+	if (!w)
+		return nfs_ok;
+	if (!argp->minorversion)
+		return nfserr_bad_xdr;
+	switch (w & NFS4_SHARE_WANT_MASK) {
+	case NFS4_SHARE_WANT_NO_PREFERENCE:
+	case NFS4_SHARE_WANT_READ_DELEG:
+	case NFS4_SHARE_WANT_WRITE_DELEG:
+	case NFS4_SHARE_WANT_ANY_DELEG:
+	case NFS4_SHARE_WANT_NO_DELEG:
+	case NFS4_SHARE_WANT_CANCEL:
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+	w &= ~NFS4_SHARE_WANT_MASK;
+	if (!w)
+		return nfs_ok;
+
+	if (!deleg_when)	/* open_downgrade */
+		return nfserr_inval;
+	switch (w) {
+	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
+	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
+	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
+	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
+		return nfs_ok;
+	}
+	return nfserr_bad_xdr;
+}
+
+static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
+{
+	if (xdr_stream_decode_u32(argp->xdr, x) < 0)
+		return nfserr_bad_xdr;
+	/* Note: unlike access bits, deny bits may be zero. */
+	if (*x & ~NFS4_SHARE_DENY_BOTH)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open_claim4(struct nfsd4_compoundargs *argp,
+			 struct nfsd4_open *open)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_claim_type) < 0)
+		return nfserr_bad_xdr;
+	switch (open->op_claim_type) {
+	case NFS4_OPEN_CLAIM_NULL:
+	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
+		status = nfsd4_decode_component4(argp, &open->op_fname,
+						 &open->op_fnamelen);
+		if (status)
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_PREVIOUS:
+		if (xdr_stream_decode_u32(argp->xdr, &open->op_delegate_type) < 0)
+			return nfserr_bad_xdr;
+		break;
+	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
+		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		status = nfsd4_decode_component4(argp, &open->op_fname,
+						 &open->op_fnamelen);
+		if (status)
+			return status;
+		break;
+	case NFS4_OPEN_CLAIM_FH:
+	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		/* void */
+		break;
+	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
+		if (argp->minorversion < 1)
+			return nfserr_bad_xdr;
+		status = nfsd4_decode_stateid4(argp, &open->op_delegate_stateid);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	__be32 status;
+	u32 dummy;
+
+	memset(open, 0, sizeof(*open));
+
+	if (xdr_stream_decode_u32(argp->xdr, &open->op_seqid) < 0)
+		return nfserr_bad_xdr;
+	/* deleg_want is ignored */
+	status = nfsd4_decode_share_access(argp, &open->op_share_access,
+					   &open->op_deleg_want, &dummy);
+	if (status)
+		return status;
+	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
+	if (status)
+		return status;
+	status = nfsd4_decode_state_owner4(argp, &open->op_clientid,
+					   &open->op_owner);
+	if (status)
+		return status;
+	status = nfsd4_decode_openflag4(argp, open);
+	if (status)
+		return status;
+	return nfsd4_decode_open_claim4(argp, open);
+}
+
+static __be32
+nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *open_conf = &u->open_confirm;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_stateid4(argp, &open_conf->oc_req_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &open_conf->oc_seqid) < 0)
+		return nfserr_bad_xdr;
+
+	memset(&open_conf->oc_resp_stateid, 0,
+	       sizeof(open_conf->oc_resp_stateid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *open_down = &u->open_downgrade;
+	__be32 status;
+
+	memset(open_down, 0, sizeof(*open_down));
+	status = nfsd4_decode_stateid4(argp, &open_down->od_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &open_down->od_seqid) < 0)
+		return nfserr_bad_xdr;
+	/* deleg_want is ignored */
+	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
+					   &open_down->od_deleg_want, NULL);
+	if (status)
+		return status;
+	return nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
+}
+
+static __be32
+nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_putfh *putfh = &u->putfh;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &putfh->pf_fhlen) < 0)
+		return nfserr_bad_xdr;
+	if (putfh->pf_fhlen > NFS4_FHSIZE)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, putfh->pf_fhlen);
+	if (!p)
+		return nfserr_bad_xdr;
+	putfh->pf_fhval = svcxdr_savemem(argp, p, putfh->pf_fhlen);
+	if (!putfh->pf_fhval)
+		return nfserr_jukebox;
+
+	putfh->no_verify = false;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
+{
+	if (argp->minorversion == 0)
+		return nfs_ok;
+	return nfserr_notsupp;
+}
+
+static __be32
+nfsd4_decode_read(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	__be32 status;
+
+	memset(read, 0, sizeof(*read));
+	status = nfsd4_decode_stateid4(argp, &read->rd_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &read->rd_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &read->rd_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	__be32 status;
+
+	memset(readdir, 0, sizeof(*readdir));
+	if (xdr_stream_decode_u64(argp->xdr, &readdir->rd_cookie) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_verifier4(argp, &readdir->rd_verf);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_dircount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &readdir->rd_maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_uint32_array(argp->xdr, readdir->rd_bmval,
+					   ARRAY_SIZE(readdir->rd_bmval)) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_remove(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	memset(&remove->rm_cinfo, 0, sizeof(remove->rm_cinfo));
+	return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
+}
+
+static __be32
+nfsd4_decode_rename(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	__be32 status;
+
+	memset(rename, 0, sizeof(*rename));
+	status = nfsd4_decode_component4(argp, &rename->rn_sname, &rename->rn_snamelen);
+	if (status)
+		return status;
+	return nfsd4_decode_component4(argp, &rename->rn_tname, &rename->rn_tnamelen);
+}
+
+static __be32
+nfsd4_decode_renew(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	clientid_t *clientid = &u->renew;
+	return nfsd4_decode_clientid4(argp, clientid);
+}
+
+static __be32
+nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	secinfo->si_exp = NULL;
+	return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
+}
+
+static __be32
+nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	__be32 status;
+
+	memset(setattr, 0, sizeof(*setattr));
+	status = nfsd4_decode_stateid4(argp, &setattr->sa_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_fattr4(argp, setattr->sa_bmval,
+				   ARRAY_SIZE(setattr->sa_bmval),
+				   &setattr->sa_iattr, &setattr->sa_acl,
+				   &setattr->sa_label, NULL);
+}
+
+static __be32
+nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *setclientid = &u->setclientid;
+	__be32 *p, status;
+
+	memset(setclientid, 0, sizeof(*setclientid));
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_verifier4(argp, &setclientid->se_verf);
+	if (status)
+		return status;
+	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_prog) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_netid_len) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_netid_len);
+	if (!p)
+		return nfserr_bad_xdr;
+	setclientid->se_callback_netid_val = svcxdr_savemem(argp, p,
+						setclientid->se_callback_netid_len);
+	if (!setclientid->se_callback_netid_val)
+		return nfserr_jukebox;
+
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_addr_len) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, setclientid->se_callback_addr_len);
+	if (!p)
+		return nfserr_bad_xdr;
+	setclientid->se_callback_addr_val = svcxdr_savemem(argp, p,
+						setclientid->se_callback_addr_len);
+	if (!setclientid->se_callback_addr_val)
+		return nfserr_jukebox;
+	if (xdr_stream_decode_u32(argp->xdr, &setclientid->se_callback_ident) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp,
+				 union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid_confirm *scd_c = &u->setclientid_confirm;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_clientid4(argp, &scd_c->sc_clientid);
+	if (status)
+		return status;
+	return nfsd4_decode_verifier4(argp, &scd_c->sc_confirm);
+}
+
+/* Also used for NVERIFY */
+static __be32
+nfsd4_decode_verify(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_verify *verify = &u->verify;
+	__be32 *p, status;
+
+	memset(verify, 0, sizeof(*verify));
+
+	status = nfsd4_decode_bitmap4(argp, verify->ve_bmval,
+				      ARRAY_SIZE(verify->ve_bmval));
+	if (status)
+		return status;
+
+	/* For convenience's sake, we compare raw xdr'd attributes in
+	 * nfsd4_proc_verify */
+
+	if (xdr_stream_decode_u32(argp->xdr, &verify->ve_attrlen) < 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, verify->ve_attrlen);
+	if (!p)
+		return nfserr_bad_xdr;
+	verify->ve_attrval = svcxdr_savemem(argp, p, verify->ve_attrlen);
+	if (!verify->ve_attrval)
+		return nfserr_jukebox;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_write(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &write->wr_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &write->wr_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &write->wr_stable_how) < 0)
+		return nfserr_bad_xdr;
+	if (write->wr_stable_how > NFS_FILE_SYNC)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &write->wr_buflen) < 0)
+		return nfserr_bad_xdr;
+	if (!xdr_stream_subsegment(argp->xdr, &write->wr_payload, write->wr_buflen))
+		return nfserr_bad_xdr;
+
+	write->wr_bytes_written = 0;
+	write->wr_how_written = 0;
+	memset(&write->wr_verifier, 0, sizeof(write->wr_verifier));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp,
+			       union nfsd4_op_u *u)
+{
+	struct nfsd4_release_lockowner *rlockowner = &u->release_lockowner;
+	__be32 status;
+
+	if (argp->minorversion >= 1)
+		return nfserr_notsupp;
+
+	status = nfsd4_decode_state_owner4(argp, &rlockowner->rl_clientid,
+					   &rlockowner->rl_owner);
+	if (status)
+		return status;
+
+	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
+		return nfserr_inval;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp,
+					   union nfsd4_op_u *u)
+{
+	struct nfsd4_backchannel_ctl *bc = &u->backchannel_ctl;
+	memset(bc, 0, sizeof(*bc));
+	if (xdr_stream_decode_u32(argp->xdr, &bc->bc_cb_program) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
+}
+
+static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp,
+						union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	u32 use_conn_in_rdma_mode;
+	__be32 status;
+
+	memset(bcts, 0, sizeof(*bcts));
+	status = nfsd4_decode_sessionid4(argp, &bcts->sessionid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &bcts->dir) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &use_conn_in_rdma_mode) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_protect_ops(struct nfsd4_compoundargs *argp,
+			       struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	status = nfsd4_decode_bitmap4(argp, exid->spo_must_enforce,
+				      ARRAY_SIZE(exid->spo_must_enforce));
+	if (status)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_bitmap4(argp, exid->spo_must_allow,
+				      ARRAY_SIZE(exid->spo_must_allow));
+	if (status)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+/*
+ * This implementation currently does not support SP4_SSV.
+ * This decoder simply skips over these arguments.
+ */
+static noinline __be32
+nfsd4_decode_ssv_sp_parms(struct nfsd4_compoundargs *argp,
+			  struct nfsd4_exchange_id *exid)
+{
+	u32 count, window, num_gss_handles;
+	__be32 status;
+
+	/* ssp_ops */
+	status = nfsd4_decode_state_protect_ops(argp, exid);
+	if (status)
+		return status;
+
+	/* ssp_hash_algs<> */
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	while (count--) {
+		status = nfsd4_decode_ignored_string(argp, 0);
+		if (status)
+			return status;
+	}
+
+	/* ssp_encr_algs<> */
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	while (count--) {
+		status = nfsd4_decode_ignored_string(argp, 0);
+		if (status)
+			return status;
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &window) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &num_gss_handles) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_state_protect4_a(struct nfsd4_compoundargs *argp,
+			      struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+
+	if (xdr_stream_decode_u32(argp->xdr, &exid->spa_how) < 0)
+		return nfserr_bad_xdr;
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		status = nfsd4_decode_state_protect_ops(argp, exid);
+		if (status)
+			return status;
+		break;
+	case SP4_SSV:
+		status = nfsd4_decode_ssv_sp_parms(argp, exid);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_nfs_impl_id4(struct nfsd4_compoundargs *argp,
+			  struct nfsd4_exchange_id *exid)
+{
+	__be32 status;
+	u32 count;
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	switch (count) {
+	case 0:
+		break;
+	case 1:
+		/* Note that RFC 8881 places no length limit on
+		 * nii_domain, but this implementation permits no
+		 * more than NFS4_OPAQUE_LIMIT bytes */
+		status = nfsd4_decode_opaque(argp, &exid->nii_domain);
+		if (status)
+			return status;
+		/* Note that RFC 8881 places no length limit on
+		 * nii_name, but this implementation permits no
+		 * more than NFS4_OPAQUE_LIMIT bytes */
+		status = nfsd4_decode_opaque(argp, &exid->nii_name);
+		if (status)
+			return status;
+		status = nfsd4_decode_nfstime4(argp, &exid->nii_time);
+		if (status)
+			return status;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	__be32 status;
+
+	memset(exid, 0, sizeof(*exid));
+	status = nfsd4_decode_verifier4(argp, &exid->verifier);
+	if (status)
+		return status;
+	status = nfsd4_decode_opaque(argp, &exid->clname);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &exid->flags) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_state_protect4_a(argp, exid);
+	if (status)
+		return status;
+	return nfsd4_decode_nfs_impl_id4(argp, exid);
+}
+
+static __be32
+nfsd4_decode_channel_attrs4(struct nfsd4_compoundargs *argp,
+			    struct nfsd4_channel_attrs *ca)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 7);
+	if (!p)
+		return nfserr_bad_xdr;
+
+	/* headerpadsz is ignored */
+	p++;
+	ca->maxreq_sz = be32_to_cpup(p++);
+	ca->maxresp_sz = be32_to_cpup(p++);
+	ca->maxresp_cached = be32_to_cpup(p++);
+	ca->maxops = be32_to_cpup(p++);
+	ca->maxreqs = be32_to_cpup(p++);
+	ca->nr_rdma_attrs = be32_to_cpup(p);
+	switch (ca->nr_rdma_attrs) {
+	case 0:
+		break;
+	case 1:
+		if (xdr_stream_decode_u32(argp->xdr, &ca->rdma_attrs) < 0)
+			return nfserr_bad_xdr;
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *sess = &u->create_session;
+	__be32 status;
+
+	memset(sess, 0, sizeof(*sess));
+	status = nfsd4_decode_clientid4(argp, &sess->clientid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->seqid) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->flags) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_channel_attrs4(argp, &sess->fore_channel);
+	if (status)
+		return status;
+	status = nfsd4_decode_channel_attrs4(argp, &sess->back_channel);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &sess->callback_prog) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_cb_sec(argp, &sess->cb_sec);
+}
+
+static __be32
+nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
+			     union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_session *destroy_session = &u->destroy_session;
+	return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
+}
+
+static __be32
+nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_free_stateid *free_stateid = &u->free_stateid;
+	return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
+	__be32 status;
+
+	memset(gdev, 0, sizeof(*gdev));
+	status = nfsd4_decode_deviceid4(argp, &gdev->gd_devid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &gdev->gd_maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_uint32_array(argp->xdr,
+					   &gdev->gd_notify_types, 1) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	__be32 *p, status;
+
+	memset(lcp, 0, sizeof(*lcp));
+	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_seg.length) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &lcp->lc_reclaim) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lcp->lc_sid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lcp->lc_newoffset) < 0)
+		return nfserr_bad_xdr;
+	if (lcp->lc_newoffset) {
+		if (xdr_stream_decode_u64(argp->xdr, &lcp->lc_last_wr) < 0)
+			return nfserr_bad_xdr;
+	} else
+		lcp->lc_last_wr = 0;
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT);
+	if (!p)
+		return nfserr_bad_xdr;
+	if (xdr_item_is_present(p)) {
+		status = nfsd4_decode_nfstime4(argp, &lcp->lc_mtime);
+		if (status)
+			return status;
+	} else {
+		lcp->lc_mtime.tv_nsec = UTIME_NOW;
+	}
+	return nfsd4_decode_layoutupdate4(argp, lcp);
+}
+
+static __be32
+nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	__be32 status;
+
+	memset(lgp, 0, sizeof(*lgp));
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_signal) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_seg.iomode) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_seg.length) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &lgp->lg_minlength) < 0)
+		return nfserr_bad_xdr;
+	status = nfsd4_decode_stateid4(argp, &lgp->lg_sid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u32(argp->xdr, &lgp->lg_maxcount) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	memset(lrp, 0, sizeof(*lrp));
+	if (xdr_stream_decode_bool(argp->xdr, &lrp->lr_reclaim) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_layout_type) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &lrp->lr_seg.iomode) < 0)
+		return nfserr_bad_xdr;
+	return nfsd4_decode_layoutreturn4(argp, lrp);
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
+					   union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo_no_name *sin = &u->secinfo_no_name;
+	if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
+		return nfserr_bad_xdr;
+
+	sin->sin_exp = NULL;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	__be32 *p, status;
+
+	status = nfsd4_decode_sessionid4(argp, &seq->sessionid);
+	if (status)
+		return status;
+	p = xdr_inline_decode(argp->xdr, XDR_UNIT * 4);
+	if (!p)
+		return nfserr_bad_xdr;
+	seq->seqid = be32_to_cpup(p++);
+	seq->slotid = be32_to_cpup(p++);
+	seq->maxslots = be32_to_cpup(p++);
+	seq->cachethis = be32_to_cpup(p);
+
+	seq->status_flags = 0;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct nfsd4_test_stateid_id *stateid;
+	__be32 status;
+	u32 i;
+
+	memset(test_stateid, 0, sizeof(*test_stateid));
+	if (xdr_stream_decode_u32(argp->xdr, &test_stateid->ts_num_ids) < 0)
+		return nfserr_bad_xdr;
+
+	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
+	for (i = 0; i < test_stateid->ts_num_ids; i++) {
+		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
+		if (!stateid)
+			return nfserr_jukebox;
+		INIT_LIST_HEAD(&stateid->ts_id_list);
+		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
+		status = nfsd4_decode_stateid4(argp, &stateid->ts_id_stateid);
+		if (status)
+			return status;
+	}
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp,
+					    union nfsd4_op_u *u)
+{
+	struct nfsd4_destroy_clientid *dc = &u->destroy_clientid;
+	return nfsd4_decode_clientid4(argp, &dc->clientid);
+}
+
+static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
+					    union nfsd4_op_u *u)
+{
+	struct nfsd4_reclaim_complete *rc = &u->reclaim_complete;
+	if (xdr_stream_decode_bool(argp->xdr, &rc->rca_one_fs) < 0)
+		return nfserr_bad_xdr;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
+		       union nfsd4_op_u *u)
+{
+	struct nfsd4_fallocate *fallocate = &u->allocate;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &fallocate->falloc_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &fallocate->falloc_length) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+static __be32 nfsd4_decode_nl4_server(struct nfsd4_compoundargs *argp,
+				      struct nl4_server *ns)
+{
+	struct nfs42_netaddr *naddr;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &ns->nl4_type) < 0)
+		return nfserr_bad_xdr;
+
+	/* currently support for 1 inter-server source server */
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		naddr = &ns->u.nl4_addr;
+
+		if (xdr_stream_decode_u32(argp->xdr, &naddr->netid_len) < 0)
+			return nfserr_bad_xdr;
+		if (naddr->netid_len > RPCBIND_MAXNETIDLEN)
+			return nfserr_bad_xdr;
+
+		p = xdr_inline_decode(argp->xdr, naddr->netid_len);
+		if (!p)
+			return nfserr_bad_xdr;
+		memcpy(naddr->netid, p, naddr->netid_len);
+
+		if (xdr_stream_decode_u32(argp->xdr, &naddr->addr_len) < 0)
+			return nfserr_bad_xdr;
+		if (naddr->addr_len > RPCBIND_MAXUADDRLEN)
+			return nfserr_bad_xdr;
+
+		p = xdr_inline_decode(argp->xdr, naddr->addr_len);
+		if (!p)
+			return nfserr_bad_xdr;
+		memcpy(naddr->addr, p, naddr->addr_len);
+		break;
+	default:
+		return nfserr_bad_xdr;
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_copy(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_copy *copy = &u->copy;
+	u32 consecutive, i, count, sync;
+	struct nl4_server *ns_dummy;
+	__be32 status;
+
+	memset(copy, 0, sizeof(*copy));
+	status = nfsd4_decode_stateid4(argp, &copy->cp_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid4(argp, &copy->cp_dst_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_src_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_dst_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &copy->cp_count) < 0)
+		return nfserr_bad_xdr;
+	/* ca_consecutive: we always do consecutive copies */
+	if (xdr_stream_decode_u32(argp->xdr, &consecutive) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_bool(argp->xdr, &sync) < 0)
+		return nfserr_bad_xdr;
+	nfsd4_copy_set_sync(copy, sync);
+
+	if (xdr_stream_decode_u32(argp->xdr, &count) < 0)
+		return nfserr_bad_xdr;
+	copy->cp_src = svcxdr_tmpalloc(argp, sizeof(*copy->cp_src));
+	if (copy->cp_src == NULL)
+		return nfserr_jukebox;
+	if (count == 0) { /* intra-server copy */
+		__set_bit(NFSD4_COPY_F_INTRA, &copy->cp_flags);
+		return nfs_ok;
+	}
+
+	/* decode all the supplied server addresses but use only the first */
+	status = nfsd4_decode_nl4_server(argp, copy->cp_src);
+	if (status)
+		return status;
+
+	ns_dummy = kmalloc(sizeof(struct nl4_server), GFP_KERNEL);
+	if (ns_dummy == NULL)
+		return nfserr_jukebox;
+	for (i = 0; i < count - 1; i++) {
+		status = nfsd4_decode_nl4_server(argp, ns_dummy);
+		if (status) {
+			kfree(ns_dummy);
+			return status;
+		}
+	}
+	kfree(ns_dummy);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_copy_notify(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	__be32 status;
+
+	memset(cn, 0, sizeof(*cn));
+	cn->cpn_src = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_src));
+	if (cn->cpn_src == NULL)
+		return nfserr_jukebox;
+	cn->cpn_dst = svcxdr_tmpalloc(argp, sizeof(*cn->cpn_dst));
+	if (cn->cpn_dst == NULL)
+		return nfserr_jukebox;
+
+	status = nfsd4_decode_stateid4(argp, &cn->cpn_src_stateid);
+	if (status)
+		return status;
+	return nfsd4_decode_nl4_server(argp, cn->cpn_dst);
+}
+
+static __be32
+nfsd4_decode_offload_status(struct nfsd4_compoundargs *argp,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	os->count = 0;
+	os->status = 0;
+	return nfsd4_decode_stateid4(argp, &os->stateid);
+}
+
+static __be32
+nfsd4_decode_seek(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &seek->seek_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &seek->seek_offset) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u32(argp->xdr, &seek->seek_whence) < 0)
+		return nfserr_bad_xdr;
+
+	seek->seek_eof = 0;
+	seek->seek_pos = 0;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_clone(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u)
+{
+	struct nfsd4_clone *clone = &u->clone;
+	__be32 status;
+
+	status = nfsd4_decode_stateid4(argp, &clone->cl_src_stateid);
+	if (status)
+		return status;
+	status = nfsd4_decode_stateid4(argp, &clone->cl_dst_stateid);
+	if (status)
+		return status;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_src_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_dst_pos) < 0)
+		return nfserr_bad_xdr;
+	if (xdr_stream_decode_u64(argp->xdr, &clone->cl_count) < 0)
+		return nfserr_bad_xdr;
+
+	return nfs_ok;
+}
+
+/*
+ * XDR data that is more than PAGE_SIZE in size is normally part of a
+ * read or write. However, the size of extended attributes is limited
+ * by the maximum request size, and then further limited by the underlying
+ * filesystem limits. This can exceed PAGE_SIZE (currently, XATTR_SIZE_MAX
+ * is 64k). Since there is no kvec- or page-based interface to xattrs,
+ * and we're not dealing with contiguous pages, we need to do some copying.
+ */
+
+/*
+ * Decode data into buffer.
+ */
+static __be32
+nfsd4_vbuf_from_vector(struct nfsd4_compoundargs *argp, struct xdr_buf *xdr,
+		       char **bufp, u32 buflen)
+{
+	struct page **pages = xdr->pages;
+	struct kvec *head = xdr->head;
+	char *tmp, *dp;
+	u32 len;
+
+	if (buflen <= head->iov_len) {
+		/*
+		 * We're in luck, the head has enough space. Just return
+		 * the head, no need for copying.
+		 */
+		*bufp = head->iov_base;
+		return 0;
+	}
+
+	tmp = svcxdr_tmpalloc(argp, buflen);
+	if (tmp == NULL)
+		return nfserr_jukebox;
+
+	dp = tmp;
+	memcpy(dp, head->iov_base, head->iov_len);
+	buflen -= head->iov_len;
+	dp += head->iov_len;
+
+	while (buflen > 0) {
+		len = min_t(u32, buflen, PAGE_SIZE);
+		memcpy(dp, page_address(*pages), len);
+
+		buflen -= len;
+		dp += len;
+		pages++;
+	}
+
+	*bufp = tmp;
+	return 0;
+}
+
+/*
+ * Get a user extended attribute name from the XDR buffer.
+ * It will not have the "user." prefix, so prepend it.
+ * Lastly, check for nul characters in the name.
+ */
+static __be32
+nfsd4_decode_xattr_name(struct nfsd4_compoundargs *argp, char **namep)
+{
+	char *name, *sp, *dp;
+	u32 namelen, cnt;
+	__be32 *p;
+
+	if (xdr_stream_decode_u32(argp->xdr, &namelen) < 0)
+		return nfserr_bad_xdr;
+	if (namelen > (XATTR_NAME_MAX - XATTR_USER_PREFIX_LEN))
+		return nfserr_nametoolong;
+	if (namelen == 0)
+		return nfserr_bad_xdr;
+	p = xdr_inline_decode(argp->xdr, namelen);
+	if (!p)
+		return nfserr_bad_xdr;
+	name = svcxdr_tmpalloc(argp, namelen + XATTR_USER_PREFIX_LEN + 1);
+	if (!name)
+		return nfserr_jukebox;
+	memcpy(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+
+	/*
+	 * Copy the extended attribute name over while checking for 0
+	 * characters.
+	 */
+	sp = (char *)p;
+	dp = name + XATTR_USER_PREFIX_LEN;
+	cnt = namelen;
+
+	while (cnt-- > 0) {
+		if (*sp == '\0')
+			return nfserr_bad_xdr;
+		*dp++ = *sp++;
+	}
+	*dp = '\0';
+
+	*namep = name;
+
+	return nfs_ok;
+}
+
+/*
+ * A GETXATTR op request comes without a length specifier. We just set the
+ * maximum length for the reply based on XATTR_SIZE_MAX and the maximum
+ * channel reply size. nfsd_getxattr will probe the length of the xattr,
+ * check it against getxa_len, and allocate + return the value.
+ */
+static __be32
+nfsd4_decode_getxattr(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+	__be32 status;
+	u32 maxcount;
+
+	memset(getxattr, 0, sizeof(*getxattr));
+	status = nfsd4_decode_xattr_name(argp, &getxattr->getxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	getxattr->getxa_len = maxcount;
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	u32 flags, maxcount, size;
+	__be32 status;
+
+	memset(setxattr, 0, sizeof(*setxattr));
+
+	if (xdr_stream_decode_u32(argp->xdr, &flags) < 0)
+		return nfserr_bad_xdr;
+
+	if (flags > SETXATTR4_REPLACE)
+		return nfserr_inval;
+	setxattr->setxa_flags = flags;
+
+	status = nfsd4_decode_xattr_name(argp, &setxattr->setxa_name);
+	if (status)
+		return status;
+
+	maxcount = svc_max_payload(argp->rqstp);
+	maxcount = min_t(u32, XATTR_SIZE_MAX, maxcount);
+
+	if (xdr_stream_decode_u32(argp->xdr, &size) < 0)
+		return nfserr_bad_xdr;
+	if (size > maxcount)
+		return nfserr_xattr2big;
+
+	setxattr->setxa_len = size;
+	if (size > 0) {
+		struct xdr_buf payload;
+
+		if (!xdr_stream_subsegment(argp->xdr, &payload, size))
+			return nfserr_bad_xdr;
+		status = nfsd4_vbuf_from_vector(argp, &payload,
+						&setxattr->setxa_buf, size);
+	}
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_listxattrs(struct nfsd4_compoundargs *argp,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
+	u32 maxcount;
+
+	memset(listxattrs, 0, sizeof(*listxattrs));
+
+	if (xdr_stream_decode_u64(argp->xdr, &listxattrs->lsxa_cookie) < 0)
+		return nfserr_bad_xdr;
+
+	/*
+	 * If the cookie  is too large to have even one user.x attribute
+	 * plus trailing '\0' left in a maximum size buffer, it's invalid.
+	 */
+	if (listxattrs->lsxa_cookie >=
+	    (XATTR_LIST_MAX / (XATTR_USER_PREFIX_LEN + 2)))
+		return nfserr_badcookie;
+
+	if (xdr_stream_decode_u32(argp->xdr, &maxcount) < 0)
+		return nfserr_bad_xdr;
+	if (maxcount < 8)
+		/* Always need at least 2 words (length and one character) */
+		return nfserr_inval;
+
+	maxcount = min(maxcount, svc_max_payload(argp->rqstp));
+	listxattrs->lsxa_maxcount = maxcount;
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_removexattr(struct nfsd4_compoundargs *argp,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	memset(removexattr, 0, sizeof(*removexattr));
+	return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
+}
+
+static __be32
+nfsd4_decode_noop(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
+{
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, union nfsd4_op_u *p)
+{
+	return nfserr_notsupp;
+}
+
+typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, union nfsd4_op_u *u);
+
+static const nfsd4_dec nfsd4_dec_ops[] = {
+	[OP_ACCESS]		= nfsd4_decode_access,
+	[OP_CLOSE]		= nfsd4_decode_close,
+	[OP_COMMIT]		= nfsd4_decode_commit,
+	[OP_CREATE]		= nfsd4_decode_create,
+	[OP_DELEGPURGE]		= nfsd4_decode_notsupp,
+	[OP_DELEGRETURN]	= nfsd4_decode_delegreturn,
+	[OP_GETATTR]		= nfsd4_decode_getattr,
+	[OP_GETFH]		= nfsd4_decode_noop,
+	[OP_LINK]		= nfsd4_decode_link,
+	[OP_LOCK]		= nfsd4_decode_lock,
+	[OP_LOCKT]		= nfsd4_decode_lockt,
+	[OP_LOCKU]		= nfsd4_decode_locku,
+	[OP_LOOKUP]		= nfsd4_decode_lookup,
+	[OP_LOOKUPP]		= nfsd4_decode_noop,
+	[OP_NVERIFY]		= nfsd4_decode_verify,
+	[OP_OPEN]		= nfsd4_decode_open,
+	[OP_OPENATTR]		= nfsd4_decode_notsupp,
+	[OP_OPEN_CONFIRM]	= nfsd4_decode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= nfsd4_decode_open_downgrade,
+	[OP_PUTFH]		= nfsd4_decode_putfh,
+	[OP_PUTPUBFH]		= nfsd4_decode_putpubfh,
+	[OP_PUTROOTFH]		= nfsd4_decode_noop,
+	[OP_READ]		= nfsd4_decode_read,
+	[OP_READDIR]		= nfsd4_decode_readdir,
+	[OP_READLINK]		= nfsd4_decode_noop,
+	[OP_REMOVE]		= nfsd4_decode_remove,
+	[OP_RENAME]		= nfsd4_decode_rename,
+	[OP_RENEW]		= nfsd4_decode_renew,
+	[OP_RESTOREFH]		= nfsd4_decode_noop,
+	[OP_SAVEFH]		= nfsd4_decode_noop,
+	[OP_SECINFO]		= nfsd4_decode_secinfo,
+	[OP_SETATTR]		= nfsd4_decode_setattr,
+	[OP_SETCLIENTID]	= nfsd4_decode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = nfsd4_decode_setclientid_confirm,
+	[OP_VERIFY]		= nfsd4_decode_verify,
+	[OP_WRITE]		= nfsd4_decode_write,
+	[OP_RELEASE_LOCKOWNER]	= nfsd4_decode_release_lockowner,
+
+	/* new operations for NFSv4.1 */
+	[OP_BACKCHANNEL_CTL]	= nfsd4_decode_backchannel_ctl,
+	[OP_BIND_CONN_TO_SESSION] = nfsd4_decode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= nfsd4_decode_exchange_id,
+	[OP_CREATE_SESSION]	= nfsd4_decode_create_session,
+	[OP_DESTROY_SESSION]	= nfsd4_decode_destroy_session,
+	[OP_FREE_STATEID]	= nfsd4_decode_free_stateid,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_decode_notsupp,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= nfsd4_decode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= nfsd4_decode_layoutcommit,
+	[OP_LAYOUTGET]		= nfsd4_decode_layoutget,
+	[OP_LAYOUTRETURN]	= nfsd4_decode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= nfsd4_decode_notsupp,
+	[OP_GETDEVICELIST]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTCOMMIT]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTGET]		= nfsd4_decode_notsupp,
+	[OP_LAYOUTRETURN]	= nfsd4_decode_notsupp,
+#endif
+	[OP_SECINFO_NO_NAME]	= nfsd4_decode_secinfo_no_name,
+	[OP_SEQUENCE]		= nfsd4_decode_sequence,
+	[OP_SET_SSV]		= nfsd4_decode_notsupp,
+	[OP_TEST_STATEID]	= nfsd4_decode_test_stateid,
+	[OP_WANT_DELEGATION]	= nfsd4_decode_notsupp,
+	[OP_DESTROY_CLIENTID]	= nfsd4_decode_destroy_clientid,
+	[OP_RECLAIM_COMPLETE]	= nfsd4_decode_reclaim_complete,
+
+	/* new operations for NFSv4.2 */
+	[OP_ALLOCATE]		= nfsd4_decode_fallocate,
+	[OP_COPY]		= nfsd4_decode_copy,
+	[OP_COPY_NOTIFY]	= nfsd4_decode_copy_notify,
+	[OP_DEALLOCATE]		= nfsd4_decode_fallocate,
+	[OP_IO_ADVISE]		= nfsd4_decode_notsupp,
+	[OP_LAYOUTERROR]	= nfsd4_decode_notsupp,
+	[OP_LAYOUTSTATS]	= nfsd4_decode_notsupp,
+	[OP_OFFLOAD_CANCEL]	= nfsd4_decode_offload_status,
+	[OP_OFFLOAD_STATUS]	= nfsd4_decode_offload_status,
+	[OP_READ_PLUS]		= nfsd4_decode_read,
+	[OP_SEEK]		= nfsd4_decode_seek,
+	[OP_WRITE_SAME]		= nfsd4_decode_notsupp,
+	[OP_CLONE]		= nfsd4_decode_clone,
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= nfsd4_decode_getxattr,
+	[OP_SETXATTR]		= nfsd4_decode_setxattr,
+	[OP_LISTXATTRS]		= nfsd4_decode_listxattrs,
+	[OP_REMOVEXATTR]	= nfsd4_decode_removexattr,
+};
+
+static inline bool
+nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
+{
+	if (op->opnum < FIRST_NFS4_OP)
+		return false;
+	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
+		return false;
+	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
+		return false;
+	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
+		return false;
+	return true;
+}
+
+static bool
+nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
+{
+	struct nfsd4_op *op;
+	bool cachethis = false;
+	int auth_slack= argp->rqstp->rq_auth_slack;
+	int max_reply = auth_slack + 8; /* opcnt, status */
+	int readcount = 0;
+	int readbytes = 0;
+	__be32 *p;
+	int i;
+
+	if (xdr_stream_decode_u32(argp->xdr, &argp->taglen) < 0)
+		return false;
+	max_reply += XDR_UNIT;
+	argp->tag = NULL;
+	if (unlikely(argp->taglen)) {
+		if (argp->taglen > NFSD4_MAX_TAGLEN)
+			return false;
+		p = xdr_inline_decode(argp->xdr, argp->taglen);
+		if (!p)
+			return false;
+		argp->tag = svcxdr_savemem(argp, p, argp->taglen);
+		if (!argp->tag)
+			return false;
+		max_reply += xdr_align_size(argp->taglen);
+	}
+
+	if (xdr_stream_decode_u32(argp->xdr, &argp->minorversion) < 0)
+		return false;
+	if (xdr_stream_decode_u32(argp->xdr, &argp->client_opcnt) < 0)
+		return false;
+	argp->opcnt = min_t(u32, argp->client_opcnt,
+			    NFSD_MAX_OPS_PER_COMPOUND);
+
+	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
+		argp->ops = vcalloc(argp->opcnt, sizeof(*argp->ops));
+		if (!argp->ops) {
+			argp->ops = argp->iops;
+			return false;
+		}
+	}
+
+	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
+		argp->opcnt = 0;
+
+	for (i = 0; i < argp->opcnt; i++) {
+		op = &argp->ops[i];
+		op->replay = NULL;
+		op->opdesc = NULL;
+
+		if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
+			return false;
+		if (nfsd4_opnum_in_range(argp, op)) {
+			op->opdesc = OPDESC(op);
+			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
+			if (op->status != nfs_ok)
+				trace_nfsd_compound_decode_err(argp->rqstp,
+							       argp->opcnt, i,
+							       op->opnum,
+							       op->status);
+		} else {
+			op->opnum = OP_ILLEGAL;
+			op->status = nfserr_op_illegal;
+		}
+
+		/*
+		 * We'll try to cache the result in the DRC if any one
+		 * op in the compound wants to be cached:
+		 */
+		cachethis |= nfsd4_cache_this_op(op);
+
+		if (op->opnum == OP_READ || op->opnum == OP_READ_PLUS) {
+			readcount++;
+			readbytes += nfsd4_max_reply(argp->rqstp, op);
+		} else
+			max_reply += nfsd4_max_reply(argp->rqstp, op);
+		/*
+		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
+		 * (Special case because it will just skip encoding this
+		 * if it runs out of xdr buffer space, and it is the only
+		 * operation that behaves this way.)
+		 */
+		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
+			max_reply += NFS4_OPAQUE_LIMIT;
+
+		if (op->status) {
+			argp->opcnt = i+1;
+			break;
+		}
+	}
+	/* Sessions make the DRC unnecessary: */
+	if (argp->minorversion)
+		cachethis = false;
+	svc_reserve(argp->rqstp, max_reply + readbytes);
+	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
+
+	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
+		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
+
+	return true;
+}
+
+static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
+			     struct svc_export *exp)
+{
+	if (exp->ex_flags & NFSEXP_V4ROOT) {
+		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
+		*p++ = 0;
+	} else
+		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
+	return p;
+}
+
+static __be32 nfsd4_encode_nfstime4(struct xdr_stream *xdr,
+				    struct timespec64 *tv)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, XDR_UNIT * 3);
+	if (!p)
+		return nfserr_resource;
+
+	p = xdr_encode_hyper(p, (s64)tv->tv_sec);
+	*p = cpu_to_be32(tv->tv_nsec);
+	return nfs_ok;
+}
+
+/*
+ * ctime (in NFSv4, time_metadata) is not writeable, and the client
+ * doesn't really care what resolution could theoretically be stored by
+ * the filesystem.
+ *
+ * The client cares how close together changes can be while still
+ * guaranteeing ctime changes.  For most filesystems (which have
+ * timestamps with nanosecond fields) that is limited by the resolution
+ * of the time returned from current_time() (which I'm assuming to be
+ * 1/HZ).
+ */
+static __be32 *encode_time_delta(__be32 *p, struct inode *inode)
+{
+	struct timespec64 ts;
+	u32 ns;
+
+	ns = max_t(u32, NSEC_PER_SEC/HZ, inode->i_sb->s_time_gran);
+	ts = ns_to_timespec64(ns);
+
+	p = xdr_encode_hyper(p, ts.tv_sec);
+	*p++ = cpu_to_be32(ts.tv_nsec);
+
+	return p;
+}
+
+static __be32
+nfsd4_encode_change_info4(struct xdr_stream *xdr, struct nfsd4_change_info *c)
+{
+	if (xdr_stream_encode_bool(xdr, c->atomic) < 0)
+		return nfserr_resource;
+	if (xdr_stream_encode_u64(xdr, c->before_change) < 0)
+		return nfserr_resource;
+	if (xdr_stream_encode_u64(xdr, c->after_change) < 0)
+		return nfserr_resource;
+	return nfs_ok;
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep, escaped with esc_enter and esc_exit.
+ */
+static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
+					  char *components, char esc_enter,
+					  char esc_exit)
+{
+	__be32 *p;
+	__be32 pathlen;
+	int pathlen_offset;
+	int strlen, count=0;
+	char *str, *end, *next;
+
+	dprintk("nfsd4_encode_components(%s)\n", components);
+
+	pathlen_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	p++; /* We will fill this in with @count later */
+
+	end = str = components;
+	while (*end) {
+		bool found_esc = false;
+
+		/* try to parse as esc_start, ..., esc_end, sep */
+		if (*str == esc_enter) {
+			for (; *end && (*end != esc_exit); end++)
+				/* find esc_exit or end of string */;
+			next = end + 1;
+			if (*end && (!*next || *next == sep)) {
+				str++;
+				found_esc = true;
+			}
+		}
+
+		if (!found_esc)
+			for (; *end && (*end != sep); end++)
+				/* find sep or end of string */;
+
+		strlen = end - str;
+		if (strlen) {
+			p = xdr_reserve_space(xdr, strlen + 4);
+			if (!p)
+				return nfserr_resource;
+			p = xdr_encode_opaque(p, str, strlen);
+			count++;
+		}
+		else
+			end++;
+		if (found_esc)
+			end = next;
+
+		str = end;
+	}
+	pathlen = htonl(count);
+	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
+	return 0;
+}
+
+/* Encode as an array of strings the string given with components
+ * separated @sep.
+ */
+static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
+				      char *components)
+{
+	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
+}
+
+/*
+ * encode a location element of a fs_locations structure
+ */
+static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
+					struct nfsd4_fs_location *location)
+{
+	__be32 status;
+
+	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
+						'[', ']');
+	if (status)
+		return status;
+	status = nfsd4_encode_components(xdr, '/', location->path);
+	if (status)
+		return status;
+	return 0;
+}
+
+/*
+ * Encode a path in RFC3530 'pathname4' format
+ */
+static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
+				const struct path *root,
+				const struct path *path)
+{
+	struct path cur = *path;
+	__be32 *p;
+	struct dentry **components = NULL;
+	unsigned int ncomponents = 0;
+	__be32 err = nfserr_jukebox;
+
+	dprintk("nfsd4_encode_components(");
+
+	path_get(&cur);
+	/* First walk the path up to the nfsd root, and store the
+	 * dentries/path components in an array.
+	 */
+	for (;;) {
+		if (path_equal(&cur, root))
+			break;
+		if (cur.dentry == cur.mnt->mnt_root) {
+			if (follow_up(&cur))
+				continue;
+			goto out_free;
+		}
+		if ((ncomponents & 15) == 0) {
+			struct dentry **new;
+			new = krealloc(components,
+					sizeof(*new) * (ncomponents + 16),
+					GFP_KERNEL);
+			if (!new)
+				goto out_free;
+			components = new;
+		}
+		components[ncomponents++] = cur.dentry;
+		cur.dentry = dget_parent(cur.dentry);
+	}
+	err = nfserr_resource;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		goto out_free;
+	*p++ = cpu_to_be32(ncomponents);
+
+	while (ncomponents) {
+		struct dentry *dentry = components[ncomponents - 1];
+		unsigned int len;
+
+		spin_lock(&dentry->d_lock);
+		len = dentry->d_name.len;
+		p = xdr_reserve_space(xdr, len + 4);
+		if (!p) {
+			spin_unlock(&dentry->d_lock);
+			goto out_free;
+		}
+		p = xdr_encode_opaque(p, dentry->d_name.name, len);
+		dprintk("/%pd", dentry);
+		spin_unlock(&dentry->d_lock);
+		dput(dentry);
+		ncomponents--;
+	}
+
+	err = 0;
+out_free:
+	dprintk(")\n");
+	while (ncomponents)
+		dput(components[--ncomponents]);
+	kfree(components);
+	path_put(&cur);
+	return err;
+}
+
+static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
+			struct svc_rqst *rqstp, const struct path *path)
+{
+	struct svc_export *exp_ps;
+	__be32 res;
+
+	exp_ps = rqst_find_fsidzero_export(rqstp);
+	if (IS_ERR(exp_ps))
+		return nfserrno(PTR_ERR(exp_ps));
+	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
+	exp_put(exp_ps);
+	return res;
+}
+
+/*
+ *  encode a fs_locations structure
+ */
+static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
+			struct svc_rqst *rqstp, struct svc_export *exp)
+{
+	__be32 status;
+	int i;
+	__be32 *p;
+	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
+
+	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
+	if (status)
+		return status;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(fslocs->locations_count);
+	for (i=0; i<fslocs->locations_count; i++) {
+		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
+		if (status)
+			return status;
+	}
+	return 0;
+}
+
+static u32 nfs4_file_type(umode_t mode)
+{
+	switch (mode & S_IFMT) {
+	case S_IFIFO:	return NF4FIFO;
+	case S_IFCHR:	return NF4CHR;
+	case S_IFDIR:	return NF4DIR;
+	case S_IFBLK:	return NF4BLK;
+	case S_IFLNK:	return NF4LNK;
+	case S_IFREG:	return NF4REG;
+	case S_IFSOCK:	return NF4SOCK;
+	default:	return NF4BAD;
+	}
+}
+
+static inline __be32
+nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+		     struct nfs4_ace *ace)
+{
+	if (ace->whotype != NFS4_ACL_WHO_NAMED)
+		return nfs4_acl_write_who(xdr, ace->whotype);
+	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
+		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
+	else
+		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
+}
+
+static inline __be32
+nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
+{
+	__be32		*p;
+	unsigned long	i = hweight_long(layout_types);
+
+	p = xdr_reserve_space(xdr, 4 + 4 * i);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(i);
+
+	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
+		if (layout_types & (1 << i))
+			*p++ = cpu_to_be32(i);
+
+	return 0;
+}
+
+#define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
+			      FATTR4_WORD0_RDATTR_ERROR)
+#define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
+#define WORD2_ABSENT_FS_ATTRS 0
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    void *context, int len)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
+	if (!p)
+		return nfserr_resource;
+
+	/*
+	 * For now we use a 0 here to indicate the null translation; in
+	 * the future we may place a call to translation code here.
+	 */
+	*p++ = cpu_to_be32(0); /* lfs */
+	*p++ = cpu_to_be32(0); /* pi */
+	p = xdr_encode_opaque(p, context, len);
+	return 0;
+}
+#else
+static inline __be32
+nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
+			    void *context, int len)
+{ return 0; }
+#endif
+
+static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
+{
+	/* As per referral draft:  */
+	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
+	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
+		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
+	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
+			*rdattr_err = NFSERR_MOVED;
+		else
+			return nfserr_moved;
+	}
+	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
+	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
+	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
+	return 0;
+}
+
+
+static int nfsd4_get_mounted_on_ino(struct svc_export *exp, u64 *pino)
+{
+	struct path path = exp->ex_path;
+	struct kstat stat;
+	int err;
+
+	path_get(&path);
+	while (follow_up(&path)) {
+		if (path.dentry != path.mnt->mnt_root)
+			break;
+	}
+	err = vfs_getattr(&path, &stat, STATX_INO, AT_STATX_SYNC_AS_STAT);
+	path_put(&path);
+	if (!err)
+		*pino = stat.ino;
+	return err;
+}
+
+static __be32
+nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
+{
+	__be32 *p;
+
+	if (bmval2) {
+		p = xdr_reserve_space(xdr, 16);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+		*p++ = cpu_to_be32(bmval2);
+	} else if (bmval1) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(2);
+		*p++ = cpu_to_be32(bmval0);
+		*p++ = cpu_to_be32(bmval1);
+	} else {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+		*p++ = cpu_to_be32(bmval0);
+	}
+
+	return 0;
+out_resource:
+	return nfserr_resource;
+}
+
+/*
+ * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
+ * ourselves.
+ */
+static __be32
+nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
+		struct svc_export *exp,
+		struct dentry *dentry, u32 *bmval,
+		struct svc_rqst *rqstp, int ignore_crossmnt)
+{
+	u32 bmval0 = bmval[0];
+	u32 bmval1 = bmval[1];
+	u32 bmval2 = bmval[2];
+	struct kstat stat;
+	struct svc_fh *tempfh = NULL;
+	struct kstatfs statfs;
+	__be32 *p, *attrlen_p;
+	int starting_len = xdr->buf->len;
+	int attrlen_offset;
+	u32 dummy;
+	u64 dummy64;
+	u32 rdattr_err = 0;
+	__be32 status;
+	int err;
+	struct nfs4_acl *acl = NULL;
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	void *context = NULL;
+	int contextlen;
+#endif
+	bool contextsupport = false;
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	u32 minorversion = resp->cstate.minorversion;
+	struct path path = {
+		.mnt	= exp->ex_path.mnt,
+		.dentry	= dentry,
+	};
+	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
+
+	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
+	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
+
+	if (exp->ex_fslocs.migrated) {
+		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
+		if (status)
+			goto out;
+	}
+	if (bmval0 & (FATTR4_WORD0_CHANGE | FATTR4_WORD0_SIZE)) {
+		status = nfsd4_deleg_getattr_conflict(rqstp, d_inode(dentry));
+		if (status)
+			goto out;
+	}
+
+	err = vfs_getattr(&path, &stat,
+			  STATX_BASIC_STATS | STATX_BTIME | STATX_CHANGE_COOKIE,
+			  AT_STATX_SYNC_AS_STAT);
+	if (err)
+		goto out_nfserr;
+	if (!(stat.result_mask & STATX_BTIME))
+		/* underlying FS does not offer btime so we can't share it */
+		bmval1 &= ~FATTR4_WORD1_TIME_CREATE;
+	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
+			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
+	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
+		       FATTR4_WORD1_SPACE_TOTAL))) {
+		err = vfs_statfs(&path, &statfs);
+		if (err)
+			goto out_nfserr;
+	}
+	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
+		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
+		status = nfserr_jukebox;
+		if (!tempfh)
+			goto out;
+		fh_init(tempfh, NFS4_FHSIZE);
+		status = fh_compose(tempfh, exp, dentry, NULL);
+		if (status)
+			goto out;
+		fhp = tempfh;
+	}
+	if (bmval0 & FATTR4_WORD0_ACL) {
+		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
+		if (err == -EOPNOTSUPP)
+			bmval0 &= ~FATTR4_WORD0_ACL;
+		else if (err == -EINVAL) {
+			status = nfserr_attrnotsupp;
+			goto out;
+		} else if (err != 0)
+			goto out_nfserr;
+	}
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
+	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
+		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
+			err = security_inode_getsecctx(d_inode(dentry),
+						&context, &contextlen);
+		else
+			err = -EOPNOTSUPP;
+		contextsupport = (err == 0);
+		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
+			if (err == -EOPNOTSUPP)
+				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
+			else if (err)
+				goto out_nfserr;
+		}
+	}
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+
+	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
+	if (status)
+		goto out;
+
+	attrlen_offset = xdr->buf->len;
+	attrlen_p = xdr_reserve_space(xdr, XDR_UNIT);
+	if (!attrlen_p)
+		goto out_resource;
+
+	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
+		u32 supp[3];
+
+		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
+
+		if (!IS_POSIXACL(dentry->d_inode))
+			supp[0] &= ~FATTR4_WORD0_ACL;
+		if (!contextsupport)
+			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
+		if (!supp[2]) {
+			p = xdr_reserve_space(xdr, 12);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(2);
+			*p++ = cpu_to_be32(supp[0]);
+			*p++ = cpu_to_be32(supp[1]);
+		} else {
+			p = xdr_reserve_space(xdr, 16);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(3);
+			*p++ = cpu_to_be32(supp[0]);
+			*p++ = cpu_to_be32(supp[1]);
+			*p++ = cpu_to_be32(supp[2]);
+		}
+	}
+	if (bmval0 & FATTR4_WORD0_TYPE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		dummy = nfs4_file_type(stat.mode);
+		if (dummy == NF4BAD) {
+			status = nfserr_serverfault;
+			goto out;
+		}
+		*p++ = cpu_to_be32(dummy);
+	}
+	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
+			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
+		else
+			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
+						NFS4_FH_VOL_RENAME);
+	}
+	if (bmval0 & FATTR4_WORD0_CHANGE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = encode_change(p, &stat, d_inode(dentry), exp);
+	}
+	if (bmval0 & FATTR4_WORD0_SIZE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, stat.size);
+	}
+	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_FSID) {
+		p = xdr_reserve_space(xdr, 16);
+		if (!p)
+			goto out_resource;
+		if (exp->ex_fslocs.migrated) {
+			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
+			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
+		} else switch(fsid_source(fhp)) {
+		case FSIDSOURCE_FSID:
+			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
+			p = xdr_encode_hyper(p, (u64)0);
+			break;
+		case FSIDSOURCE_DEV:
+			*p++ = cpu_to_be32(0);
+			*p++ = cpu_to_be32(MAJOR(stat.dev));
+			*p++ = cpu_to_be32(0);
+			*p++ = cpu_to_be32(MINOR(stat.dev));
+			break;
+		case FSIDSOURCE_UUID:
+			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
+								EX_UUID_LEN);
+			break;
+		}
+	}
+	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(nn->nfsd4_lease);
+	}
+	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(rdattr_err);
+	}
+	if (bmval0 & FATTR4_WORD0_ACL) {
+		struct nfs4_ace *ace;
+
+		if (acl == NULL) {
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				goto out_resource;
+
+			*p++ = cpu_to_be32(0);
+			goto out_acl;
+		}
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(acl->naces);
+
+		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
+			p = xdr_reserve_space(xdr, 4*3);
+			if (!p)
+				goto out_resource;
+			*p++ = cpu_to_be32(ace->type);
+			*p++ = cpu_to_be32(ace->flag);
+			*p++ = cpu_to_be32(ace->access_mask &
+							NFS4_ACE_MASK_ALL);
+			status = nfsd4_encode_aclname(xdr, rqstp, ace);
+			if (status)
+				goto out;
+		}
+	}
+out_acl:
+	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
+			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
+	}
+	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(0);
+	}
+	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
+		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw,
+					fhp->fh_handle.fh_size);
+	}
+	if (bmval0 & FATTR4_WORD0_FILEID) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, stat.ino);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
+	}
+	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) statfs.f_files);
+	}
+	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
+		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
+		if (status)
+			goto out;
+	}
+	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXLINK) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(255);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXNAME) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(statfs.f_namelen);
+	}
+	if (bmval0 & FATTR4_WORD0_MAXREAD) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
+	}
+	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
+	}
+	if (bmval1 & FATTR4_WORD1_MODE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
+	}
+	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(1);
+	}
+	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.nlink);
+	}
+	if (bmval1 & FATTR4_WORD1_OWNER) {
+		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
+		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_RAWDEV) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
+		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			goto out_resource;
+		dummy64 = (u64)stat.blocks << 9;
+		p = xdr_encode_hyper(p, dummy64);
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
+		status = nfsd4_encode_nfstime4(xdr, &stat.atime);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
+		status = nfsd4_encode_nfstime4(xdr, &stat.btime);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
+		p = xdr_reserve_space(xdr, 12);
+		if (!p)
+			goto out_resource;
+		p = encode_time_delta(p, d_inode(dentry));
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
+		status = nfsd4_encode_nfstime4(xdr, &stat.ctime);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
+		status = nfsd4_encode_nfstime4(xdr, &stat.mtime);
+		if (status)
+			goto out;
+	}
+	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
+		u64 ino = stat.ino;
+
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+                	goto out_resource;
+		/*
+		 * Get ino of mountpoint in parent filesystem, if not ignoring
+		 * crossmount and this is the root of a cross-mounted
+		 * filesystem.
+		 */
+		if (ignore_crossmnt == 0 &&
+		    dentry == exp->ex_path.mnt->mnt_root) {
+			err = nfsd4_get_mounted_on_ino(exp, &ino);
+			if (err)
+				goto out_nfserr;
+		}
+		p = xdr_encode_hyper(p, ino);
+	}
+#ifdef CONFIG_NFSD_PNFS
+	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
+		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
+		if (status)
+			goto out;
+	}
+
+	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
+		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
+		if (status)
+			goto out;
+	}
+
+	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		*p++ = cpu_to_be32(stat.blksize);
+	}
+#endif /* CONFIG_NFSD_PNFS */
+	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
+		u32 supp[3];
+
+		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
+		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
+		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
+		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
+
+		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
+		if (status)
+			goto out;
+	}
+
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
+		status = nfsd4_encode_security_label(xdr, rqstp, context,
+								contextlen);
+		if (status)
+			goto out;
+	}
+#endif
+
+	if (bmval2 & FATTR4_WORD2_XATTR_SUPPORT) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			goto out_resource;
+		err = xattr_supports_user_prefix(d_inode(dentry));
+		*p++ = cpu_to_be32(err == 0);
+	}
+
+	*attrlen_p = cpu_to_be32(xdr->buf->len - attrlen_offset - XDR_UNIT);
+	status = nfs_ok;
+
+out:
+#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
+	if (context)
+		security_release_secctx(context, contextlen);
+#endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
+	kfree(acl);
+	if (tempfh) {
+		fh_put(tempfh);
+		kfree(tempfh);
+	}
+	if (status)
+		xdr_truncate_encode(xdr, starting_len);
+	return status;
+out_nfserr:
+	status = nfserrno(err);
+	goto out;
+out_resource:
+	status = nfserr_resource;
+	goto out;
+}
+
+static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
+				struct xdr_buf *buf, __be32 *p, int bytes)
+{
+	xdr->scratch.iov_len = 0;
+	memset(buf, 0, sizeof(struct xdr_buf));
+	buf->head[0].iov_base = p;
+	buf->head[0].iov_len = 0;
+	buf->len = 0;
+	xdr->buf = buf;
+	xdr->iov = buf->head;
+	xdr->p = p;
+	xdr->end = (void *)p + bytes;
+	buf->buflen = bytes;
+}
+
+__be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
+			struct svc_fh *fhp, struct svc_export *exp,
+			struct dentry *dentry, u32 *bmval,
+			struct svc_rqst *rqstp, int ignore_crossmnt)
+{
+	struct xdr_buf dummy;
+	struct xdr_stream xdr;
+	__be32 ret;
+
+	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
+	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
+							ignore_crossmnt);
+	*p = xdr.p;
+	return ret;
+}
+
+static inline int attributes_need_mount(u32 *bmval)
+{
+	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
+		return 1;
+	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
+		return 1;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
+			const char *name, int namlen)
+{
+	struct svc_export *exp = cd->rd_fhp->fh_export;
+	struct dentry *dentry;
+	__be32 nfserr;
+	int ignore_crossmnt = 0;
+
+	dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
+	if (IS_ERR(dentry))
+		return nfserrno(PTR_ERR(dentry));
+
+	exp_get(exp);
+	/*
+	 * In the case of a mountpoint, the client may be asking for
+	 * attributes that are only properties of the underlying filesystem
+	 * as opposed to the cross-mounted file system. In such a case,
+	 * we will not follow the cross mount and will fill the attribtutes
+	 * directly from the mountpoint dentry.
+	 */
+	if (nfsd_mountpoint(dentry, exp)) {
+		int err;
+
+		if (!(exp->ex_flags & NFSEXP_V4ROOT)
+				&& !attributes_need_mount(cd->rd_bmval)) {
+			ignore_crossmnt = 1;
+			goto out_encode;
+		}
+		/*
+		 * Why the heck aren't we just using nfsd_lookup??
+		 * Different "."/".." handling?  Something else?
+		 * At least, add a comment here to explain....
+		 */
+		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
+		if (err) {
+			nfserr = nfserrno(err);
+			goto out_put;
+		}
+		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
+		if (nfserr)
+			goto out_put;
+
+	}
+out_encode:
+	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
+					cd->rd_rqstp, ignore_crossmnt);
+out_put:
+	dput(dentry);
+	exp_put(exp);
+	return nfserr;
+}
+
+static __be32 *
+nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 20);
+	if (!p)
+		return NULL;
+	*p++ = htonl(2);
+	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
+	*p++ = htonl(0);			 /* bmval1 */
+
+	*p++ = htonl(4);     /* attribute length */
+	*p++ = nfserr;       /* no htonl */
+	return p;
+}
+
+static int
+nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
+		    loff_t offset, u64 ino, unsigned int d_type)
+{
+	struct readdir_cd *ccd = ccdv;
+	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
+	struct xdr_stream *xdr = cd->xdr;
+	int start_offset = xdr->buf->len;
+	int cookie_offset;
+	u32 name_and_cookie;
+	int entry_bytes;
+	__be32 nfserr = nfserr_toosmall;
+	__be64 wire_offset;
+	__be32 *p;
+
+	/* In nfsv4, "." and ".." never make it onto the wire.. */
+	if (name && isdotent(name, namlen)) {
+		cd->common.err = nfs_ok;
+		return 0;
+	}
+
+	if (cd->cookie_offset) {
+		wire_offset = cpu_to_be64(offset);
+		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
+							&wire_offset, 8);
+	}
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		goto fail;
+	*p++ = xdr_one;                             /* mark entry present */
+	cookie_offset = xdr->buf->len;
+	p = xdr_reserve_space(xdr, 3*4 + namlen);
+	if (!p)
+		goto fail;
+	p = xdr_encode_hyper(p, OFFSET_MAX);        /* offset of next entry */
+	p = xdr_encode_array(p, name, namlen);      /* name length & name */
+
+	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
+	switch (nfserr) {
+	case nfs_ok:
+		break;
+	case nfserr_resource:
+		nfserr = nfserr_toosmall;
+		goto fail;
+	case nfserr_noent:
+		xdr_truncate_encode(xdr, start_offset);
+		goto skip_entry;
+	case nfserr_jukebox:
+		/*
+		 * The pseudoroot should only display dentries that lead to
+		 * exports. If we get EJUKEBOX here, then we can't tell whether
+		 * this entry should be included. Just fail the whole READDIR
+		 * with NFS4ERR_DELAY in that case, and hope that the situation
+		 * will resolve itself by the client's next attempt.
+		 */
+		if (cd->rd_fhp->fh_export->ex_flags & NFSEXP_V4ROOT)
+			goto fail;
+		fallthrough;
+	default:
+		/*
+		 * If the client requested the RDATTR_ERROR attribute,
+		 * we stuff the error code into this attribute
+		 * and continue.  If this attribute was not requested,
+		 * then in accordance with the spec, we fail the
+		 * entire READDIR operation(!)
+		 */
+		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
+			goto fail;
+		p = nfsd4_encode_rdattr_error(xdr, nfserr);
+		if (p == NULL) {
+			nfserr = nfserr_toosmall;
+			goto fail;
+		}
+	}
+	nfserr = nfserr_toosmall;
+	entry_bytes = xdr->buf->len - start_offset;
+	if (entry_bytes > cd->rd_maxcount)
+		goto fail;
+	cd->rd_maxcount -= entry_bytes;
+	/*
+	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", and
+	 * notes that it could be zero. If it is zero, then the server
+	 * should enforce only the rd_maxcount value.
+	 */
+	if (cd->rd_dircount) {
+		name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
+		if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
+			goto fail;
+		cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
+		if (!cd->rd_dircount)
+			cd->rd_maxcount = 0;
+	}
+
+	cd->cookie_offset = cookie_offset;
+skip_entry:
+	cd->common.err = nfs_ok;
+	return 0;
+fail:
+	xdr_truncate_encode(xdr, start_offset);
+	cd->common.err = nfserr;
+	return -EINVAL;
+}
+
+static __be32
+nfsd4_encode_verifier4(struct xdr_stream *xdr, const nfs4_verifier *verf)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+	memcpy(p, verf->data, sizeof(verf->data));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_clientid4(struct xdr_stream *xdr, const clientid_t *clientid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(__be64));
+	if (!p)
+		return nfserr_resource;
+	memcpy(p, clientid, sizeof(*clientid));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, sizeof(stateid_t));
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(sid->si_generation);
+	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
+					sizeof(stateid_opaque_t));
+	return 0;
+}
+
+static __be32
+nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_access *access = &u->access;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(access->ac_supported);
+	*p++ = cpu_to_be32(access->ac_resp_access);
+	return 0;
+}
+
+static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr,
+						union nfsd4_op_u *u)
+{
+	struct nfsd4_bind_conn_to_session *bcts = &u->bind_conn_to_session;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(bcts->dir);
+	/* Upshifting from TCP to RDMA is not supported */
+	*p++ = cpu_to_be32(0);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_close *close = &u->close;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
+}
+
+
+static __be32
+nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_commit *commit = &u->commit;
+
+	return nfsd4_encode_verifier4(resp->xdr, &commit->co_verf);
+}
+
+static __be32
+nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_create *create = &u->create;
+	struct xdr_stream *xdr = resp->xdr;
+
+	nfserr = nfsd4_encode_change_info4(xdr, &create->cr_cinfo);
+	if (nfserr)
+		return nfserr;
+	return nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
+			create->cr_bmval[1], create->cr_bmval[2]);
+}
+
+static __be32
+nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_getattr *getattr = &u->getattr;
+	struct svc_fh *fhp = getattr->ga_fhp;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
+				    getattr->ga_bmval, resp->rqstp, 0);
+}
+
+static __be32
+nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct svc_fh **fhpp = &u->getfh;
+	struct xdr_stream *xdr = resp->xdr;
+	struct svc_fh *fhp = *fhpp;
+	unsigned int len;
+	__be32 *p;
+
+	len = fhp->fh_handle.fh_size;
+	p = xdr_reserve_space(xdr, len + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_raw, len);
+	return 0;
+}
+
+/*
+* Including all fields other than the name, a LOCK4denied structure requires
+*   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
+*/
+static __be32
+nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
+{
+	struct xdr_netobj *conf = &ld->ld_owner;
+	__be32 *p;
+
+again:
+	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
+	if (!p) {
+		/*
+		 * Don't fail to return the result just because we can't
+		 * return the conflicting open:
+		 */
+		if (conf->len) {
+			kfree(conf->data);
+			conf->len = 0;
+			conf->data = NULL;
+			goto again;
+		}
+		return nfserr_resource;
+	}
+	p = xdr_encode_hyper(p, ld->ld_start);
+	p = xdr_encode_hyper(p, ld->ld_length);
+	*p++ = cpu_to_be32(ld->ld_type);
+	if (conf->len) {
+		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
+		p = xdr_encode_opaque(p, conf->data, conf->len);
+		kfree(conf->data);
+	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
+		p = xdr_encode_hyper(p, (u64)0); /* clientid */
+		*p++ = cpu_to_be32(0); /* length of owner name */
+	}
+	return nfserr_denied;
+}
+
+static __be32
+nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_lock *lock = &u->lock;
+	struct xdr_stream *xdr = resp->xdr;
+
+	if (!nfserr)
+		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
+	else if (nfserr == nfserr_denied)
+		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
+
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_lockt *lockt = &u->lockt;
+	struct xdr_stream *xdr = resp->xdr;
+
+	if (nfserr == nfserr_denied)
+		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_locku *locku = &u->locku;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
+}
+
+
+static __be32
+nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_link *link = &u->link;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &link->li_cinfo);
+}
+
+
+static __be32
+nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_open *open = &u->open;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
+	if (nfserr)
+		return nfserr;
+	nfserr = nfsd4_encode_change_info4(xdr, &open->op_cinfo);
+	if (nfserr)
+		return nfserr;
+	if (xdr_stream_encode_u32(xdr, open->op_rflags) < 0)
+		return nfserr_resource;
+
+	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
+					open->op_bmval[2]);
+	if (nfserr)
+		return nfserr;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(open->op_delegate_type);
+	switch (open->op_delegate_type) {
+	case NFS4_OPEN_DELEGATE_NONE:
+		break;
+	case NFS4_OPEN_DELEGATE_READ:
+		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
+		if (nfserr)
+			return nfserr;
+		p = xdr_reserve_space(xdr, 20);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(open->op_recall);
+
+		/*
+		 * TODO: ACE's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
+		break;
+	case NFS4_OPEN_DELEGATE_WRITE:
+		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
+		if (nfserr)
+			return nfserr;
+
+		p = xdr_reserve_space(xdr, XDR_UNIT * 8);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(open->op_recall);
+
+		/*
+		 * Always flush on close
+		 *
+		 * TODO: space_limit's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
+		*p++ = xdr_zero;
+		*p++ = xdr_zero;
+
+		/*
+		 * TODO: ACE's in delegations
+		 */
+		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
+		break;
+	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
+		switch (open->op_why_no_deleg) {
+		case WND4_CONTENTION:
+		case WND4_RESOURCE:
+			p = xdr_reserve_space(xdr, 8);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(open->op_why_no_deleg);
+			/* deleg signaling not supported yet: */
+			*p++ = cpu_to_be32(0);
+			break;
+		default:
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(open->op_why_no_deleg);
+		}
+		break;
+	default:
+		BUG();
+	}
+	/* XXX save filehandle here */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_open_confirm *oc = &u->open_confirm;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
+}
+
+static __be32
+nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_open_downgrade *od = &u->open_downgrade;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_stateid(xdr, &od->od_stateid);
+}
+
+/*
+ * The operation of this function assumes that this is the only
+ * READ operation in the COMPOUND. If there are multiple READs,
+ * we use nfsd4_encode_readv().
+ */
+static __be32 nfsd4_encode_splice_read(
+				struct nfsd4_compoundres *resp,
+				struct nfsd4_read *read,
+				struct file *file, unsigned long maxcount)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct xdr_buf *buf = xdr->buf;
+	int status, space_left;
+	__be32 nfserr;
+
+	/*
+	 * Make sure there is room at the end of buf->head for
+	 * svcxdr_encode_opaque_pages() to create a tail buffer
+	 * to XDR-pad the payload.
+	 */
+	if (xdr->iov != xdr->buf->head || xdr->end - xdr->p < 1)
+		return nfserr_resource;
+
+	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
+				  file, read->rd_offset, &maxcount,
+				  &read->rd_eof);
+	read->rd_length = maxcount;
+	if (nfserr)
+		goto out_err;
+	svcxdr_encode_opaque_pages(read->rd_rqstp, xdr, buf->pages,
+				   buf->page_base, maxcount);
+	status = svc_encode_result_payload(read->rd_rqstp,
+					   buf->head[0].iov_len, maxcount);
+	if (status) {
+		nfserr = nfserrno(status);
+		goto out_err;
+	}
+
+	/*
+	 * Prepare to encode subsequent operations.
+	 *
+	 * xdr_truncate_encode() is not safe to use after a successful
+	 * splice read has been done, so the following stream
+	 * manipulations are open-coded.
+	 */
+	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
+				buf->buflen - buf->len);
+	buf->buflen = buf->len + space_left;
+	xdr->end = (__be32 *)((void *)xdr->end + space_left);
+
+	return nfs_ok;
+
+out_err:
+	/*
+	 * nfsd_splice_actor may have already messed with the
+	 * page length; reset it so as not to confuse
+	 * xdr_truncate_encode in our caller.
+	 */
+	buf->page_len = 0;
+	return nfserr;
+}
+
+static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
+				 struct nfsd4_read *read,
+				 struct file *file, unsigned long maxcount)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	unsigned int base = xdr->buf->page_len & ~PAGE_MASK;
+	unsigned int starting_len = xdr->buf->len;
+	__be32 zero = xdr_zero;
+	__be32 nfserr;
+
+	if (xdr_reserve_space_vec(xdr, maxcount) < 0)
+		return nfserr_resource;
+
+	nfserr = nfsd_iter_read(resp->rqstp, read->rd_fhp, file,
+				read->rd_offset, &maxcount, base,
+				&read->rd_eof);
+	read->rd_length = maxcount;
+	if (nfserr)
+		return nfserr;
+	if (svc_encode_result_payload(resp->rqstp, starting_len, maxcount))
+		return nfserr_io;
+	xdr_truncate_encode(xdr, starting_len + xdr_align_size(maxcount));
+
+	write_bytes_to_xdr_buf(xdr->buf, starting_len + maxcount, &zero,
+			       xdr_pad_size(maxcount));
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	bool splice_ok = test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags);
+	unsigned long maxcount;
+	struct xdr_stream *xdr = resp->xdr;
+	struct file *file;
+	int starting_len = xdr->buf->len;
+	__be32 *p;
+
+	if (nfserr)
+		return nfserr;
+	file = read->rd_nf->nf_file;
+
+	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
+	if (!p) {
+		WARN_ON_ONCE(splice_ok);
+		return nfserr_resource;
+	}
+	if (resp->xdr->buf->page_len && splice_ok) {
+		WARN_ON_ONCE(1);
+		return nfserr_serverfault;
+	}
+	xdr_commit_encode(xdr);
+
+	maxcount = min_t(unsigned long, read->rd_length,
+			 (xdr->buf->buflen - xdr->buf->len));
+
+	if (file->f_op->splice_read && splice_ok)
+		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+	else
+		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
+	if (nfserr) {
+		xdr_truncate_encode(xdr, starting_len);
+		return nfserr;
+	}
+
+	p = xdr_encode_bool(p, read->rd_eof);
+	*p = cpu_to_be32(read->rd_length);
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_readlink *readlink = &u->readlink;
+	__be32 *p, *maxcount_p, zero = xdr_zero;
+	struct xdr_stream *xdr = resp->xdr;
+	int length_offset = xdr->buf->len;
+	int maxcount, status;
+
+	maxcount_p = xdr_reserve_space(xdr, XDR_UNIT);
+	if (!maxcount_p)
+		return nfserr_resource;
+	maxcount = PAGE_SIZE;
+
+	p = xdr_reserve_space(xdr, maxcount);
+	if (!p)
+		return nfserr_resource;
+	/*
+	 * XXX: By default, vfs_readlink() will truncate symlinks if they
+	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
+	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
+	 * that truncation occurred, and return NFS4ERR_RESOURCE.
+	 */
+	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
+						(char *)p, &maxcount);
+	if (nfserr == nfserr_isdir)
+		nfserr = nfserr_inval;
+	if (nfserr)
+		goto out_err;
+	status = svc_encode_result_payload(readlink->rl_rqstp, length_offset,
+					   maxcount);
+	if (status) {
+		nfserr = nfserrno(status);
+		goto out_err;
+	}
+	*maxcount_p = cpu_to_be32(maxcount);
+	xdr_truncate_encode(xdr, length_offset + 4 + xdr_align_size(maxcount));
+	write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount, &zero,
+			       xdr_pad_size(maxcount));
+	return nfs_ok;
+
+out_err:
+	xdr_truncate_encode(xdr, length_offset);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_readdir *readdir = &u->readdir;
+	int maxcount;
+	int bytes_left;
+	loff_t offset;
+	__be64 wire_offset;
+	struct xdr_stream *xdr = resp->xdr;
+	int starting_len = xdr->buf->len;
+	__be32 *p;
+
+	nfserr = nfsd4_encode_verifier4(xdr, &readdir->rd_verf);
+	if (nfserr != nfs_ok)
+		return nfserr;
+
+	/*
+	 * Number of bytes left for directory entries allowing for the
+	 * final 8 bytes of the readdir and a following failed op:
+	 */
+	bytes_left = xdr->buf->buflen - xdr->buf->len
+			- COMPOUND_ERR_SLACK_SPACE - 8;
+	if (bytes_left < 0) {
+		nfserr = nfserr_resource;
+		goto err_no_verf;
+	}
+	maxcount = svc_max_payload(resp->rqstp);
+	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
+	/*
+	 * Note the rfc defines rd_maxcount as the size of the
+	 * READDIR4resok structure, which includes the verifier above
+	 * and the 8 bytes encoded at the end of this function:
+	 */
+	if (maxcount < 16) {
+		nfserr = nfserr_toosmall;
+		goto err_no_verf;
+	}
+	maxcount = min_t(int, maxcount-16, bytes_left);
+
+	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
+	if (!readdir->rd_dircount)
+		readdir->rd_dircount = svc_max_payload(resp->rqstp);
+
+	readdir->xdr = xdr;
+	readdir->rd_maxcount = maxcount;
+	readdir->common.err = 0;
+	readdir->cookie_offset = 0;
+
+	offset = readdir->rd_cookie;
+	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
+			      &offset,
+			      &readdir->common, nfsd4_encode_dirent);
+	if (nfserr == nfs_ok &&
+	    readdir->common.err == nfserr_toosmall &&
+	    xdr->buf->len == starting_len + 8) {
+		/* nothing encoded; which limit did we hit?: */
+		if (maxcount - 16 < bytes_left)
+			/* It was the fault of rd_maxcount: */
+			nfserr = nfserr_toosmall;
+		else
+			/* We ran out of buffer space: */
+			nfserr = nfserr_resource;
+	}
+	if (nfserr)
+		goto err_no_verf;
+
+	if (readdir->cookie_offset) {
+		wire_offset = cpu_to_be64(offset);
+		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
+							&wire_offset, 8);
+	}
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		goto err_no_verf;
+	}
+	*p++ = 0;	/* no more entries */
+	*p++ = htonl(readdir->common.err == nfserr_eof);
+
+	return 0;
+err_no_verf:
+	xdr_truncate_encode(xdr, starting_len);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_remove *remove = &u->remove;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &remove->rm_cinfo);
+}
+
+static __be32
+nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr,
+		    union nfsd4_op_u *u)
+{
+	struct nfsd4_rename *rename = &u->rename;
+	struct xdr_stream *xdr = resp->xdr;
+
+	nfserr = nfsd4_encode_change_info4(xdr, &rename->rn_sinfo);
+	if (nfserr)
+		return nfserr;
+	return nfsd4_encode_change_info4(xdr, &rename->rn_tinfo);
+}
+
+static __be32
+nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
+{
+	u32 i, nflavs, supported;
+	struct exp_flavor_info *flavs;
+	struct exp_flavor_info def_flavs[2];
+	__be32 *p, *flavorsp;
+	static bool report = true;
+
+	if (exp->ex_nflavors) {
+		flavs = exp->ex_flavors;
+		nflavs = exp->ex_nflavors;
+	} else { /* Handling of some defaults in absence of real secinfo: */
+		flavs = def_flavs;
+		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
+			nflavs = 2;
+			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
+			flavs[1].pseudoflavor = RPC_AUTH_NULL;
+		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= svcauth_gss_flavor(exp->ex_client);
+		} else {
+			nflavs = 1;
+			flavs[0].pseudoflavor
+					= exp->ex_client->flavour->flavour;
+		}
+	}
+
+	supported = 0;
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	flavorsp = p++;		/* to be backfilled later */
+
+	for (i = 0; i < nflavs; i++) {
+		rpc_authflavor_t pf = flavs[i].pseudoflavor;
+		struct rpcsec_gss_info info;
+
+		if (rpcauth_get_gssinfo(pf, &info) == 0) {
+			supported++;
+			p = xdr_reserve_space(xdr, 4 + 4 +
+					      XDR_LEN(info.oid.len) + 4 + 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(RPC_AUTH_GSS);
+			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
+			*p++ = cpu_to_be32(info.qop);
+			*p++ = cpu_to_be32(info.service);
+		} else if (pf < RPC_AUTH_MAXFLAVOR) {
+			supported++;
+			p = xdr_reserve_space(xdr, 4);
+			if (!p)
+				return nfserr_resource;
+			*p++ = cpu_to_be32(pf);
+		} else {
+			if (report)
+				pr_warn("NFS: SECINFO: security flavor %u "
+					"is not supported\n", pf);
+		}
+	}
+
+	if (nflavs != supported)
+		report = false;
+	*flavorsp = htonl(supported);
+	return 0;
+}
+
+static __be32
+nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo *secinfo = &u->secinfo;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
+}
+
+static __be32
+nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_secinfo_no_name *secinfo = &u->secinfo_no_name;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
+}
+
+/*
+ * The SETATTR encode routine is special -- it always encodes a bitmap,
+ * regardless of the error status.
+ */
+static __be32
+nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		     union nfsd4_op_u *u)
+{
+	struct nfsd4_setattr *setattr = &u->setattr;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 16);
+	if (!p)
+		return nfserr_resource;
+	if (nfserr) {
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+		*p++ = cpu_to_be32(0);
+	}
+	else {
+		*p++ = cpu_to_be32(3);
+		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
+		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
+		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
+	}
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_setclientid *scd = &u->setclientid;
+	struct xdr_stream *xdr = resp->xdr;
+
+	if (!nfserr) {
+		nfserr = nfsd4_encode_clientid4(xdr, &scd->se_clientid);
+		if (nfserr != nfs_ok)
+			goto out;
+		nfserr = nfsd4_encode_verifier4(xdr, &scd->se_confirm);
+	} else if (nfserr == nfserr_clid_inuse) {
+		/* empty network id */
+		if (xdr_stream_encode_u32(xdr, 0) < 0) {
+			nfserr = nfserr_resource;
+			goto out;
+		}
+		/* empty universal address */
+		if (xdr_stream_encode_u32(xdr, 0) < 0) {
+			nfserr = nfserr_resource;
+			goto out;
+		}
+	}
+out:
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr,
+		   union nfsd4_op_u *u)
+{
+	struct nfsd4_write *write = &u->write;
+
+	if (xdr_stream_encode_u32(resp->xdr, write->wr_bytes_written) < 0)
+		return nfserr_resource;
+	if (xdr_stream_encode_u32(resp->xdr, write->wr_how_written) < 0)
+		return nfserr_resource;
+	return nfsd4_encode_verifier4(resp->xdr, &write->wr_verifier);
+}
+
+static __be32
+nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_exchange_id *exid = &u->exchange_id;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+	char *major_id;
+	char *server_scope;
+	int major_id_sz;
+	int server_scope_sz;
+	uint64_t minor_id = 0;
+	struct nfsd_net *nn = net_generic(SVC_NET(resp->rqstp), nfsd_net_id);
+
+	major_id = nn->nfsd_name;
+	major_id_sz = strlen(nn->nfsd_name);
+	server_scope = nn->nfsd_name;
+	server_scope_sz = strlen(nn->nfsd_name);
+
+	if (nfsd4_encode_clientid4(xdr, &exid->clientid) != nfs_ok)
+		return nfserr_resource;
+	if (xdr_stream_encode_u32(xdr, exid->seqid) < 0)
+		return nfserr_resource;
+	if (xdr_stream_encode_u32(xdr, exid->flags) < 0)
+		return nfserr_resource;
+
+	if (xdr_stream_encode_u32(xdr, exid->spa_how) < 0)
+		return nfserr_resource;
+	switch (exid->spa_how) {
+	case SP4_NONE:
+		break;
+	case SP4_MACH_CRED:
+		/* spo_must_enforce bitmap: */
+		nfserr = nfsd4_encode_bitmap(xdr,
+					exid->spo_must_enforce[0],
+					exid->spo_must_enforce[1],
+					exid->spo_must_enforce[2]);
+		if (nfserr)
+			return nfserr;
+		/* spo_must_allow bitmap: */
+		nfserr = nfsd4_encode_bitmap(xdr,
+					exid->spo_must_allow[0],
+					exid->spo_must_allow[1],
+					exid->spo_must_allow[2]);
+		if (nfserr)
+			return nfserr;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+
+	p = xdr_reserve_space(xdr,
+		8 /* so_minor_id */ +
+		4 /* so_major_id.len */ +
+		(XDR_QUADLEN(major_id_sz) * 4) +
+		4 /* eir_server_scope.len */ +
+		(XDR_QUADLEN(server_scope_sz) * 4) +
+		4 /* eir_server_impl_id.count (0) */);
+	if (!p)
+		return nfserr_resource;
+
+	/* The server_owner struct */
+	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
+	/* major id */
+	p = xdr_encode_opaque(p, major_id, major_id_sz);
+
+	/* Server scope */
+	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
+
+	/* Implementation id */
+	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_create_session *sess = &u->create_session;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 24);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(sess->seqid);
+	*p++ = cpu_to_be32(sess->flags);
+
+	p = xdr_reserve_space(xdr, 28);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(0); /* headerpadsz */
+	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
+	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
+	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
+	*p++ = cpu_to_be32(sess->fore_channel.maxops);
+	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
+	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
+
+	if (sess->fore_channel.nr_rdma_attrs) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
+	}
+
+	p = xdr_reserve_space(xdr, 28);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(0); /* headerpadsz */
+	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
+	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
+	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
+	*p++ = cpu_to_be32(sess->back_channel.maxops);
+	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
+	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
+
+	if (sess->back_channel.nr_rdma_attrs) {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
+	}
+	return 0;
+}
+
+static __be32
+nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_sequence *seq = &u->sequence;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
+					NFS4_MAX_SESSIONID_LEN);
+	*p++ = cpu_to_be32(seq->seqid);
+	*p++ = cpu_to_be32(seq->slotid);
+	/* Note slotid's are numbered from zero: */
+	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
+	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
+	*p++ = cpu_to_be32(seq->status_flags);
+
+	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
+	return 0;
+}
+
+static __be32
+nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_test_stateid *test_stateid = &u->test_stateid;
+	struct xdr_stream *xdr = resp->xdr;
+	struct nfsd4_test_stateid_id *stateid, *next;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
+	if (!p)
+		return nfserr_resource;
+	*p++ = htonl(test_stateid->ts_num_ids);
+
+	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
+		*p++ = stateid->ts_id_status;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_NFSD_PNFS
+static __be32
+nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_getdeviceinfo *gdev = &u->getdeviceinfo;
+	struct xdr_stream *xdr = resp->xdr;
+	const struct nfsd4_layout_ops *ops;
+	u32 starting_len = xdr->buf->len, needed_len;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(gdev->gd_layout_type);
+
+	ops = nfsd4_layout_ops[gdev->gd_layout_type];
+	nfserr = ops->encode_getdeviceinfo(xdr, gdev);
+	if (nfserr) {
+		/*
+		 * We don't bother to burden the layout drivers with
+		 * enforcing gd_maxcount, just tell the client to
+		 * come back with a bigger buffer if it's not enough.
+		 */
+		if (xdr->buf->len + 4 > gdev->gd_maxcount)
+			goto toosmall;
+		return nfserr;
+	}
+
+	if (gdev->gd_notify_types) {
+		p = xdr_reserve_space(xdr, 4 + 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = cpu_to_be32(1);			/* bitmap length */
+		*p++ = cpu_to_be32(gdev->gd_notify_types);
+	} else {
+		p = xdr_reserve_space(xdr, 4);
+		if (!p)
+			return nfserr_resource;
+		*p++ = 0;
+	}
+
+	return 0;
+toosmall:
+	dprintk("%s: maxcount too small\n", __func__);
+	needed_len = xdr->buf->len + 4 /* notifications */;
+	xdr_truncate_encode(xdr, starting_len);
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(needed_len);
+	return nfserr_toosmall;
+}
+
+static __be32
+nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutget *lgp = &u->layoutget;
+	struct xdr_stream *xdr = resp->xdr;
+	const struct nfsd4_layout_ops *ops;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
+	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
+	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
+				    sizeof(stateid_opaque_t));
+
+	*p++ = cpu_to_be32(1);	/* we always return a single layout */
+	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
+	p = xdr_encode_hyper(p, lgp->lg_seg.length);
+	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
+	*p++ = cpu_to_be32(lgp->lg_layout_type);
+
+	ops = nfsd4_layout_ops[lgp->lg_layout_type];
+	return ops->encode_layoutget(xdr, lgp);
+}
+
+static __be32
+nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
+			  union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutcommit *lcp = &u->layoutcommit;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(lcp->lc_size_chg);
+	if (lcp->lc_size_chg) {
+		p = xdr_reserve_space(xdr, 8);
+		if (!p)
+			return nfserr_resource;
+		p = xdr_encode_hyper(p, lcp->lc_newsize);
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
+		union nfsd4_op_u *u)
+{
+	struct nfsd4_layoutreturn *lrp = &u->layoutreturn;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+	*p++ = cpu_to_be32(lrp->lrs_present);
+	if (lrp->lrs_present)
+		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
+	return 0;
+}
+#endif /* CONFIG_NFSD_PNFS */
+
+static __be32
+nfsd42_encode_write_res(struct nfsd4_compoundres *resp,
+		struct nfsd42_write_res *write, bool sync)
+{
+	__be32 *p;
+	p = xdr_reserve_space(resp->xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	if (sync)
+		*p++ = cpu_to_be32(0);
+	else {
+		__be32 nfserr;
+		*p++ = cpu_to_be32(1);
+		nfserr = nfsd4_encode_stateid(resp->xdr, &write->cb_stateid);
+		if (nfserr)
+			return nfserr;
+	}
+	p = xdr_reserve_space(resp->xdr, 8 + 4 + NFS4_VERIFIER_SIZE);
+	if (!p)
+		return nfserr_resource;
+
+	p = xdr_encode_hyper(p, write->wr_bytes_written);
+	*p++ = cpu_to_be32(write->wr_stable_how);
+	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
+				    NFS4_VERIFIER_SIZE);
+	return nfs_ok;
+}
+
+static __be32
+nfsd42_encode_nl4_server(struct nfsd4_compoundres *resp, struct nl4_server *ns)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct nfs42_netaddr *addr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p++ = cpu_to_be32(ns->nl4_type);
+
+	switch (ns->nl4_type) {
+	case NL4_NETADDR:
+		addr = &ns->u.nl4_addr;
+
+		/* netid_len, netid, uaddr_len, uaddr (port included
+		 * in RPCBIND_MAXUADDRLEN)
+		 */
+		p = xdr_reserve_space(xdr,
+			4 /* netid len */ +
+			(XDR_QUADLEN(addr->netid_len) * 4) +
+			4 /* uaddr len */ +
+			(XDR_QUADLEN(addr->addr_len) * 4));
+		if (!p)
+			return nfserr_resource;
+
+		*p++ = cpu_to_be32(addr->netid_len);
+		p = xdr_encode_opaque_fixed(p, addr->netid,
+					    addr->netid_len);
+		*p++ = cpu_to_be32(addr->addr_len);
+		p = xdr_encode_opaque_fixed(p, addr->addr,
+					addr->addr_len);
+		break;
+	default:
+		WARN_ON_ONCE(ns->nl4_type != NL4_NETADDR);
+		return nfserr_inval;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_copy *copy = &u->copy;
+	__be32 *p;
+
+	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res,
+					 nfsd4_copy_is_sync(copy));
+	if (nfserr)
+		return nfserr;
+
+	p = xdr_reserve_space(resp->xdr, 4 + 4);
+	*p++ = xdr_one; /* cr_consecutive */
+	*p = nfsd4_copy_is_sync(copy) ? xdr_one : xdr_zero;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_offload_status(struct nfsd4_compoundres *resp, __be32 nfserr,
+			    union nfsd4_op_u *u)
+{
+	struct nfsd4_offload_status *os = &u->offload_status;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8 + 4);
+	if (!p)
+		return nfserr_resource;
+	p = xdr_encode_hyper(p, os->count);
+	*p++ = cpu_to_be32(0);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_read_plus_data(struct nfsd4_compoundres *resp,
+			    struct nfsd4_read *read)
+{
+	bool splice_ok = test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags);
+	struct file *file = read->rd_nf->nf_file;
+	struct xdr_stream *xdr = resp->xdr;
+	unsigned long maxcount;
+	__be32 nfserr, *p;
+
+	/* Content type, offset, byte count */
+	p = xdr_reserve_space(xdr, 4 + 8 + 4);
+	if (!p)
+		return nfserr_io;
+	if (resp->xdr->buf->page_len && splice_ok) {
+		WARN_ON_ONCE(splice_ok);
+		return nfserr_serverfault;
+	}
+
+	maxcount = min_t(unsigned long, read->rd_length,
+			 (xdr->buf->buflen - xdr->buf->len));
+
+	if (file->f_op->splice_read && splice_ok)
+		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
+	else
+		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
+	if (nfserr)
+		return nfserr;
+
+	*p++ = cpu_to_be32(NFS4_CONTENT_DATA);
+	p = xdr_encode_hyper(p, read->rd_offset);
+	*p = cpu_to_be32(read->rd_length);
+
+	return nfs_ok;
+}
+
+static __be32
+nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
+		       union nfsd4_op_u *u)
+{
+	struct nfsd4_read *read = &u->read;
+	struct file *file = read->rd_nf->nf_file;
+	struct xdr_stream *xdr = resp->xdr;
+	int starting_len = xdr->buf->len;
+	u32 segments = 0;
+	__be32 *p;
+
+	if (nfserr)
+		return nfserr;
+
+	/* eof flag, segment count */
+	p = xdr_reserve_space(xdr, 4 + 4);
+	if (!p)
+		return nfserr_io;
+	xdr_commit_encode(xdr);
+
+	read->rd_eof = read->rd_offset >= i_size_read(file_inode(file));
+	if (read->rd_eof)
+		goto out;
+
+	nfserr = nfsd4_encode_read_plus_data(resp, read);
+	if (nfserr) {
+		xdr_truncate_encode(xdr, starting_len);
+		return nfserr;
+	}
+
+	segments++;
+
+out:
+	p = xdr_encode_bool(p, read->rd_eof);
+	*p = cpu_to_be32(segments);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_copy_notify *cn = &u->copy_notify;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p;
+
+	if (nfserr)
+		return nfserr;
+
+	/* 8 sec, 4 nsec */
+	p = xdr_reserve_space(xdr, 12);
+	if (!p)
+		return nfserr_resource;
+
+	/* cnr_lease_time */
+	p = xdr_encode_hyper(p, cn->cpn_sec);
+	*p++ = cpu_to_be32(cn->cpn_nsec);
+
+	/* cnr_stateid */
+	nfserr = nfsd4_encode_stateid(xdr, &cn->cpn_cnr_stateid);
+	if (nfserr)
+		return nfserr;
+
+	/* cnr_src.nl_nsvr */
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p++ = cpu_to_be32(1);
+
+	nfserr = nfsd42_encode_nl4_server(resp, cn->cpn_src);
+	return nfserr;
+}
+
+static __be32
+nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *u)
+{
+	struct nfsd4_seek *seek = &u->seek;
+	__be32 *p;
+
+	p = xdr_reserve_space(resp->xdr, 4 + 8);
+	*p++ = cpu_to_be32(seek->seek_eof);
+	p = xdr_encode_hyper(p, seek->seek_pos);
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr,
+		  union nfsd4_op_u *p)
+{
+	return nfserr;
+}
+
+/*
+ * Encode kmalloc-ed buffer in to XDR stream.
+ */
+static __be32
+nfsd4_vbuf_to_stream(struct xdr_stream *xdr, char *buf, u32 buflen)
+{
+	u32 cplen;
+	__be32 *p;
+
+	cplen = min_t(unsigned long, buflen,
+		      ((void *)xdr->end - (void *)xdr->p));
+	p = xdr_reserve_space(xdr, cplen);
+	if (!p)
+		return nfserr_resource;
+
+	memcpy(p, buf, cplen);
+	buf += cplen;
+	buflen -= cplen;
+
+	while (buflen) {
+		cplen = min_t(u32, buflen, PAGE_SIZE);
+		p = xdr_reserve_space(xdr, cplen);
+		if (!p)
+			return nfserr_resource;
+
+		memcpy(p, buf, cplen);
+
+		if (cplen < PAGE_SIZE) {
+			/*
+			 * We're done, with a length that wasn't page
+			 * aligned, so possibly not word aligned. Pad
+			 * any trailing bytes with 0.
+			 */
+			xdr_encode_opaque_fixed(p, NULL, cplen);
+			break;
+		}
+
+		buflen -= PAGE_SIZE;
+		buf += PAGE_SIZE;
+	}
+
+	return 0;
+}
+
+static __be32
+nfsd4_encode_getxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_getxattr *getxattr = &u->getxattr;
+	struct xdr_stream *xdr = resp->xdr;
+	__be32 *p, err;
+
+	p = xdr_reserve_space(xdr, 4);
+	if (!p)
+		return nfserr_resource;
+
+	*p = cpu_to_be32(getxattr->getxa_len);
+
+	if (getxattr->getxa_len == 0)
+		return 0;
+
+	err = nfsd4_vbuf_to_stream(xdr, getxattr->getxa_buf,
+				    getxattr->getxa_len);
+
+	kvfree(getxattr->getxa_buf);
+
+	return err;
+}
+
+static __be32
+nfsd4_encode_setxattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+		      union nfsd4_op_u *u)
+{
+	struct nfsd4_setxattr *setxattr = &u->setxattr;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &setxattr->setxa_cinfo);
+}
+
+/*
+ * See if there are cookie values that can be rejected outright.
+ */
+static __be32
+nfsd4_listxattr_validate_cookie(struct nfsd4_listxattrs *listxattrs,
+				u32 *offsetp)
+{
+	u64 cookie = listxattrs->lsxa_cookie;
+
+	/*
+	 * If the cookie is larger than the maximum number we can fit
+	 * in either the buffer we just got back from vfs_listxattr, or,
+	 * XDR-encoded, in the return buffer, it's invalid.
+	 */
+	if (cookie > (listxattrs->lsxa_len) / (XATTR_USER_PREFIX_LEN + 2))
+		return nfserr_badcookie;
+
+	if (cookie > (listxattrs->lsxa_maxcount /
+		      (XDR_QUADLEN(XATTR_USER_PREFIX_LEN + 2) + 4)))
+		return nfserr_badcookie;
+
+	*offsetp = (u32)cookie;
+	return 0;
+}
+
+static __be32
+nfsd4_encode_listxattrs(struct nfsd4_compoundres *resp, __be32 nfserr,
+			union nfsd4_op_u *u)
+{
+	struct nfsd4_listxattrs *listxattrs = &u->listxattrs;
+	struct xdr_stream *xdr = resp->xdr;
+	u32 cookie_offset, count_offset, eof;
+	u32 left, xdrleft, slen, count;
+	u32 xdrlen, offset;
+	u64 cookie;
+	char *sp;
+	__be32 status, tmp;
+	__be32 *p;
+	u32 nuser;
+
+	eof = 1;
+
+	status = nfsd4_listxattr_validate_cookie(listxattrs, &offset);
+	if (status)
+		goto out;
+
+	/*
+	 * Reserve space for the cookie and the name array count. Record
+	 * the offsets to save them later.
+	 */
+	cookie_offset = xdr->buf->len;
+	count_offset = cookie_offset + 8;
+	p = xdr_reserve_space(xdr, 12);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+
+	count = 0;
+	left = listxattrs->lsxa_len;
+	sp = listxattrs->lsxa_buf;
+	nuser = 0;
+
+	xdrleft = listxattrs->lsxa_maxcount;
+
+	while (left > 0 && xdrleft > 0) {
+		slen = strlen(sp);
+
+		/*
+		 * Check if this is a "user." attribute, skip it if not.
+		 */
+		if (strncmp(sp, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
+			goto contloop;
+
+		slen -= XATTR_USER_PREFIX_LEN;
+		xdrlen = 4 + ((slen + 3) & ~3);
+		if (xdrlen > xdrleft) {
+			if (count == 0) {
+				/*
+				 * Can't even fit the first attribute name.
+				 */
+				status = nfserr_toosmall;
+				goto out;
+			}
+			eof = 0;
+			goto wreof;
+		}
+
+		left -= XATTR_USER_PREFIX_LEN;
+		sp += XATTR_USER_PREFIX_LEN;
+		if (nuser++ < offset)
+			goto contloop;
+
+
+		p = xdr_reserve_space(xdr, xdrlen);
+		if (!p) {
+			status = nfserr_resource;
+			goto out;
+		}
+
+		xdr_encode_opaque(p, sp, slen);
+
+		xdrleft -= xdrlen;
+		count++;
+contloop:
+		sp += slen + 1;
+		left -= slen + 1;
+	}
+
+	/*
+	 * If there were user attributes to copy, but we didn't copy
+	 * any, the offset was too large (e.g. the cookie was invalid).
+	 */
+	if (nuser > 0 && count == 0) {
+		status = nfserr_badcookie;
+		goto out;
+	}
+
+wreof:
+	p = xdr_reserve_space(xdr, 4);
+	if (!p) {
+		status = nfserr_resource;
+		goto out;
+	}
+	*p = cpu_to_be32(eof);
+
+	cookie = offset + count;
+
+	write_bytes_to_xdr_buf(xdr->buf, cookie_offset, &cookie, 8);
+	tmp = cpu_to_be32(count);
+	write_bytes_to_xdr_buf(xdr->buf, count_offset, &tmp, 4);
+out:
+	if (listxattrs->lsxa_len)
+		kvfree(listxattrs->lsxa_buf);
+	return status;
+}
+
+static __be32
+nfsd4_encode_removexattr(struct nfsd4_compoundres *resp, __be32 nfserr,
+			 union nfsd4_op_u *u)
+{
+	struct nfsd4_removexattr *removexattr = &u->removexattr;
+	struct xdr_stream *xdr = resp->xdr;
+
+	return nfsd4_encode_change_info4(xdr, &removexattr->rmxa_cinfo);
+}
+
+typedef __be32(*nfsd4_enc)(struct nfsd4_compoundres *, __be32, union nfsd4_op_u *u);
+
+/*
+ * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
+ * since we don't need to filter out obsolete ops as this is
+ * done in the decoding phase.
+ */
+static const nfsd4_enc nfsd4_enc_ops[] = {
+	[OP_ACCESS]		= nfsd4_encode_access,
+	[OP_CLOSE]		= nfsd4_encode_close,
+	[OP_COMMIT]		= nfsd4_encode_commit,
+	[OP_CREATE]		= nfsd4_encode_create,
+	[OP_DELEGPURGE]		= nfsd4_encode_noop,
+	[OP_DELEGRETURN]	= nfsd4_encode_noop,
+	[OP_GETATTR]		= nfsd4_encode_getattr,
+	[OP_GETFH]		= nfsd4_encode_getfh,
+	[OP_LINK]		= nfsd4_encode_link,
+	[OP_LOCK]		= nfsd4_encode_lock,
+	[OP_LOCKT]		= nfsd4_encode_lockt,
+	[OP_LOCKU]		= nfsd4_encode_locku,
+	[OP_LOOKUP]		= nfsd4_encode_noop,
+	[OP_LOOKUPP]		= nfsd4_encode_noop,
+	[OP_NVERIFY]		= nfsd4_encode_noop,
+	[OP_OPEN]		= nfsd4_encode_open,
+	[OP_OPENATTR]		= nfsd4_encode_noop,
+	[OP_OPEN_CONFIRM]	= nfsd4_encode_open_confirm,
+	[OP_OPEN_DOWNGRADE]	= nfsd4_encode_open_downgrade,
+	[OP_PUTFH]		= nfsd4_encode_noop,
+	[OP_PUTPUBFH]		= nfsd4_encode_noop,
+	[OP_PUTROOTFH]		= nfsd4_encode_noop,
+	[OP_READ]		= nfsd4_encode_read,
+	[OP_READDIR]		= nfsd4_encode_readdir,
+	[OP_READLINK]		= nfsd4_encode_readlink,
+	[OP_REMOVE]		= nfsd4_encode_remove,
+	[OP_RENAME]		= nfsd4_encode_rename,
+	[OP_RENEW]		= nfsd4_encode_noop,
+	[OP_RESTOREFH]		= nfsd4_encode_noop,
+	[OP_SAVEFH]		= nfsd4_encode_noop,
+	[OP_SECINFO]		= nfsd4_encode_secinfo,
+	[OP_SETATTR]		= nfsd4_encode_setattr,
+	[OP_SETCLIENTID]	= nfsd4_encode_setclientid,
+	[OP_SETCLIENTID_CONFIRM] = nfsd4_encode_noop,
+	[OP_VERIFY]		= nfsd4_encode_noop,
+	[OP_WRITE]		= nfsd4_encode_write,
+	[OP_RELEASE_LOCKOWNER]	= nfsd4_encode_noop,
+
+	/* NFSv4.1 operations */
+	[OP_BACKCHANNEL_CTL]	= nfsd4_encode_noop,
+	[OP_BIND_CONN_TO_SESSION] = nfsd4_encode_bind_conn_to_session,
+	[OP_EXCHANGE_ID]	= nfsd4_encode_exchange_id,
+	[OP_CREATE_SESSION]	= nfsd4_encode_create_session,
+	[OP_DESTROY_SESSION]	= nfsd4_encode_noop,
+	[OP_FREE_STATEID]	= nfsd4_encode_noop,
+	[OP_GET_DIR_DELEGATION]	= nfsd4_encode_noop,
+#ifdef CONFIG_NFSD_PNFS
+	[OP_GETDEVICEINFO]	= nfsd4_encode_getdeviceinfo,
+	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= nfsd4_encode_layoutcommit,
+	[OP_LAYOUTGET]		= nfsd4_encode_layoutget,
+	[OP_LAYOUTRETURN]	= nfsd4_encode_layoutreturn,
+#else
+	[OP_GETDEVICEINFO]	= nfsd4_encode_noop,
+	[OP_GETDEVICELIST]	= nfsd4_encode_noop,
+	[OP_LAYOUTCOMMIT]	= nfsd4_encode_noop,
+	[OP_LAYOUTGET]		= nfsd4_encode_noop,
+	[OP_LAYOUTRETURN]	= nfsd4_encode_noop,
+#endif
+	[OP_SECINFO_NO_NAME]	= nfsd4_encode_secinfo_no_name,
+	[OP_SEQUENCE]		= nfsd4_encode_sequence,
+	[OP_SET_SSV]		= nfsd4_encode_noop,
+	[OP_TEST_STATEID]	= nfsd4_encode_test_stateid,
+	[OP_WANT_DELEGATION]	= nfsd4_encode_noop,
+	[OP_DESTROY_CLIENTID]	= nfsd4_encode_noop,
+	[OP_RECLAIM_COMPLETE]	= nfsd4_encode_noop,
+
+	/* NFSv4.2 operations */
+	[OP_ALLOCATE]		= nfsd4_encode_noop,
+	[OP_COPY]		= nfsd4_encode_copy,
+	[OP_COPY_NOTIFY]	= nfsd4_encode_copy_notify,
+	[OP_DEALLOCATE]		= nfsd4_encode_noop,
+	[OP_IO_ADVISE]		= nfsd4_encode_noop,
+	[OP_LAYOUTERROR]	= nfsd4_encode_noop,
+	[OP_LAYOUTSTATS]	= nfsd4_encode_noop,
+	[OP_OFFLOAD_CANCEL]	= nfsd4_encode_noop,
+	[OP_OFFLOAD_STATUS]	= nfsd4_encode_offload_status,
+	[OP_READ_PLUS]		= nfsd4_encode_read_plus,
+	[OP_SEEK]		= nfsd4_encode_seek,
+	[OP_WRITE_SAME]		= nfsd4_encode_noop,
+	[OP_CLONE]		= nfsd4_encode_noop,
+
+	/* RFC 8276 extended atributes operations */
+	[OP_GETXATTR]		= nfsd4_encode_getxattr,
+	[OP_SETXATTR]		= nfsd4_encode_setxattr,
+	[OP_LISTXATTRS]		= nfsd4_encode_listxattrs,
+	[OP_REMOVEXATTR]	= nfsd4_encode_removexattr,
+};
+
+/*
+ * Calculate whether we still have space to encode repsize bytes.
+ * There are two considerations:
+ *     - For NFS versions >=4.1, the size of the reply must stay within
+ *       session limits
+ *     - For all NFS versions, we must stay within limited preallocated
+ *       buffer space.
+ *
+ * This is called before the operation is processed, so can only provide
+ * an upper estimate.  For some nonidempotent operations (such as
+ * getattr), it's not necessarily a problem if that estimate is wrong,
+ * as we can fail it after processing without significant side effects.
+ */
+__be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
+{
+	struct xdr_buf *buf = &resp->rqstp->rq_res;
+	struct nfsd4_slot *slot = resp->cstate.slot;
+
+	if (buf->len + respsize <= buf->buflen)
+		return nfs_ok;
+	if (!nfsd4_has_session(&resp->cstate))
+		return nfserr_resource;
+	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
+		WARN_ON_ONCE(1);
+		return nfserr_rep_too_big_to_cache;
+	}
+	return nfserr_rep_too_big;
+}
+
+void
+nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
+{
+	struct xdr_stream *xdr = resp->xdr;
+	struct nfs4_stateowner *so = resp->cstate.replay_owner;
+	struct svc_rqst *rqstp = resp->rqstp;
+	const struct nfsd4_operation *opdesc = op->opdesc;
+	int post_err_offset;
+	nfsd4_enc encoder;
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 8);
+	if (!p)
+		goto release;
+	*p++ = cpu_to_be32(op->opnum);
+	post_err_offset = xdr->buf->len;
+
+	if (op->opnum == OP_ILLEGAL)
+		goto status;
+	if (op->status && opdesc &&
+			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
+		goto status;
+	BUG_ON(op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
+	       !nfsd4_enc_ops[op->opnum]);
+	encoder = nfsd4_enc_ops[op->opnum];
+	op->status = encoder(resp, op->status, &op->u);
+	if (op->status)
+		trace_nfsd_compound_encode_err(rqstp, op->opnum, op->status);
+	xdr_commit_encode(xdr);
+
+	/* nfsd4_check_resp_size guarantees enough room for error status */
+	if (!op->status) {
+		int space_needed = 0;
+		if (!nfsd4_last_compound_op(rqstp))
+			space_needed = COMPOUND_ERR_SLACK_SPACE;
+		op->status = nfsd4_check_resp_size(resp, space_needed);
+	}
+	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
+		struct nfsd4_slot *slot = resp->cstate.slot;
+
+		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
+			op->status = nfserr_rep_too_big_to_cache;
+		else
+			op->status = nfserr_rep_too_big;
+	}
+	if (op->status == nfserr_resource ||
+	    op->status == nfserr_rep_too_big ||
+	    op->status == nfserr_rep_too_big_to_cache) {
+		/*
+		 * The operation may have already been encoded or
+		 * partially encoded.  No op returns anything additional
+		 * in the case of one of these three errors, so we can
+		 * just truncate back to after the status.  But it's a
+		 * bug if we had to do this on a non-idempotent op:
+		 */
+		warn_on_nonidempotent_op(op);
+		xdr_truncate_encode(xdr, post_err_offset);
+	}
+	if (so) {
+		int len = xdr->buf->len - post_err_offset;
+
+		so->so_replay.rp_status = op->status;
+		so->so_replay.rp_buflen = len;
+		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
+						so->so_replay.rp_buf, len);
+	}
+status:
+	*p = op->status;
+release:
+	if (opdesc && opdesc->op_release)
+		opdesc->op_release(&op->u);
+
+	/*
+	 * Account for pages consumed while encoding this operation.
+	 * The xdr_stream primitives don't manage rq_next_page.
+	 */
+	rqstp->rq_next_page = xdr->page_ptr + 1;
+}
+
+/* 
+ * Encode the reply stored in the stateowner reply cache 
+ * 
+ * XDR note: do not encode rp->rp_buflen: the buffer contains the
+ * previously sent already encoded operation.
+ */
+void
+nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
+{
+	__be32 *p;
+	struct nfs4_replay *rp = op->replay;
+
+	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
+	if (!p) {
+		WARN_ON_ONCE(1);
+		return;
+	}
+	*p++ = cpu_to_be32(op->opnum);
+	*p++ = rp->rp_status;  /* already xdr'ed */
+
+	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
+}
+
+void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	if (args->ops != args->iops) {
+		vfree(args->ops);
+		args->ops = args->iops;
+	}
+	while (args->to_free) {
+		struct svcxdr_tmpbuf *tb = args->to_free;
+		args->to_free = tb->next;
+		kfree(tb);
+	}
+}
+
+bool
+nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd4_compoundargs *args = rqstp->rq_argp;
+
+	/* svcxdr_tmp_alloc */
+	args->to_free = NULL;
+
+	args->xdr = xdr;
+	args->ops = args->iops;
+	args->rqstp = rqstp;
+
+	return nfsd4_decode_compound(args);
+}
+
+bool
+nfs4svc_encode_compoundres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
+{
+	struct nfsd4_compoundres *resp = rqstp->rq_resp;
+	__be32 *p;
+
+	/*
+	 * Send buffer space for the following items is reserved
+	 * at the top of nfsd4_proc_compound().
+	 */
+	p = resp->statusp;
+
+	*p++ = resp->cstate.status;
+	*p++ = htonl(resp->taglen);
+	memcpy(p, resp->tag, resp->taglen);
+	p += XDR_QUADLEN(resp->taglen);
+	*p++ = htonl(resp->opcnt);
+
+	nfsd4_sequence_done(resp);
+	return true;
+}