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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /*
  *  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 <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,
             struct nfsd4_access *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, struct nfsd4_close *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, struct nfsd4_commit *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;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
 {
     __be32 *p, status;
 
     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, struct nfsd4_delegreturn *dr)
 {
     return nfsd4_decode_stateid4(argp, &dr->dr_stateid);
 }
 
 static inline __be32
 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
 {
     return nfsd4_decode_bitmap4(argp, getattr->ga_bmval,
                     ARRAY_SIZE(getattr->ga_bmval));
 }
 
 static __be32
 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *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, struct nfsd4_lock *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, struct nfsd4_lockt *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, struct nfsd4_locku *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, struct nfsd4_lookup *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, struct nfsd4_open *open)
 {
     __be32 status;
     u32 dummy;
 
     memset(open->op_bmval, 0, sizeof(open->op_bmval));
     open->op_iattr.ia_valid = 0;
     open->op_openowner = NULL;
 
     open->op_xdr_error = 0;
     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, struct nfsd4_open_confirm *open_conf)
 {
     __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;
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
 {
     __be32 status;
 
     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, struct nfsd4_putfh *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;
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
 {
     if (argp->minorversion == 0)
         return nfs_ok;
     return nfserr_notsupp;
 }
 
 static __be32
 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
 {
     __be32 status;
 
     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, struct nfsd4_readdir *readdir)
 {
     __be32 status;
 
     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, struct nfsd4_remove *remove)
 {
     return nfsd4_decode_component4(argp, &remove->rm_name, &remove->rm_namelen);
 }
 
 static __be32
 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
 {
     __be32 status;
 
     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, clientid_t *clientid)
 {
     return nfsd4_decode_clientid4(argp, clientid);
 }
 
 static __be32
 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
              struct nfsd4_secinfo *secinfo)
 {
     return nfsd4_decode_component4(argp, &secinfo->si_name, &secinfo->si_namelen);
 }
 
 static __be32
 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
 {
     __be32 status;
 
     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, struct nfsd4_setclientid *setclientid)
 {
     __be32 *p, status;
 
     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, struct nfsd4_setclientid_confirm *scd_c)
 {
     __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, struct nfsd4_verify *verify)
 {
     __be32 *p, status;
 
     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, struct nfsd4_write *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;
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
 {
     __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, struct nfsd4_backchannel_ctl *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, struct nfsd4_bind_conn_to_session *bcts)
 {
     u32 use_conn_in_rdma_mode;
     __be32 status;
 
     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,
              struct nfsd4_exchange_id *exid)
 {
     __be32 status;
 
     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,
                 struct nfsd4_create_session *sess)
 {
     __be32 status;
 
     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;
     status = nfsd4_decode_cb_sec(argp, &sess->cb_sec);
     if (status)
         return status;
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
                  struct nfsd4_destroy_session *destroy_session)
 {
     return nfsd4_decode_sessionid4(argp, &destroy_session->sessionid);
 }
 
 static __be32
 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
               struct nfsd4_free_stateid *free_stateid)
 {
     return nfsd4_decode_stateid4(argp, &free_stateid->fr_stateid);
 }
 
 #ifdef CONFIG_NFSD_PNFS
 static __be32
 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
         struct nfsd4_getdeviceinfo *gdev)
 {
     __be32 status;
 
     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,
               struct nfsd4_layoutcommit *lcp)
 {
     __be32 *p, status;
 
     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,
         struct nfsd4_layoutget *lgp)
 {
     __be32 status;
 
     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,
         struct nfsd4_layoutreturn *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,
                        struct nfsd4_secinfo_no_name *sin)
 {
     if (xdr_stream_decode_u32(argp->xdr, &sin->sin_style) < 0)
         return nfserr_bad_xdr;
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
               struct nfsd4_sequence *seq)
 {
     __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);
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
 {
     struct nfsd4_test_stateid_id *stateid;
     __be32 status;
     u32 i;
 
     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,
                         struct nfsd4_destroy_clientid *dc)
 {
     return nfsd4_decode_clientid4(argp, &dc->clientid);
 }
 
 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp,
                         struct nfsd4_reclaim_complete *rc)
 {
     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,
                struct nfsd4_fallocate *fallocate)
 {
     __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, struct nfsd4_copy *copy)
 {
     u32 consecutive, i, count, sync;
     struct nl4_server *ns_dummy;
     __be32 status;
 
     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,
              struct nfsd4_copy_notify *cn)
 {
     __be32 status;
 
     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,
                 struct nfsd4_offload_status *os)
 {
     return nfsd4_decode_stateid4(argp, &os->stateid);
 }
 
 static __be32
 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *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;
 
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *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,
               struct nfsd4_getxattr *getxattr)
 {
     __be32 status;
     u32 maxcount;
 
     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 status;
 }
 
 static __be32
 nfsd4_decode_setxattr(struct nfsd4_compoundargs *argp,
               struct nfsd4_setxattr *setxattr)
 {
     u32 flags, maxcount, size;
     __be32 status;
 
     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,
             struct nfsd4_listxattrs *listxattrs)
 {
     u32 maxcount;
 
     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,
              struct nfsd4_removexattr *removexattr)
 {
     return nfsd4_decode_xattr_name(argp, &removexattr->rmxa_name);
 }
 
 static __be32
 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
 {
     return nfs_ok;
 }
 
 static __be32
 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
 {
     return nfserr_notsupp;
 }
 
 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
 
 static const nfsd4_dec nfsd4_dec_ops[] = {
     [OP_ACCESS]     = (nfsd4_dec)nfsd4_decode_access,
     [OP_CLOSE]      = (nfsd4_dec)nfsd4_decode_close,
     [OP_COMMIT]     = (nfsd4_dec)nfsd4_decode_commit,
     [OP_CREATE]     = (nfsd4_dec)nfsd4_decode_create,
     [OP_DELEGPURGE]     = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_DELEGRETURN]    = (nfsd4_dec)nfsd4_decode_delegreturn,
     [OP_GETATTR]        = (nfsd4_dec)nfsd4_decode_getattr,
     [OP_GETFH]      = (nfsd4_dec)nfsd4_decode_noop,
     [OP_LINK]       = (nfsd4_dec)nfsd4_decode_link,
     [OP_LOCK]       = (nfsd4_dec)nfsd4_decode_lock,
     [OP_LOCKT]      = (nfsd4_dec)nfsd4_decode_lockt,
     [OP_LOCKU]      = (nfsd4_dec)nfsd4_decode_locku,
     [OP_LOOKUP]     = (nfsd4_dec)nfsd4_decode_lookup,
     [OP_LOOKUPP]        = (nfsd4_dec)nfsd4_decode_noop,
     [OP_NVERIFY]        = (nfsd4_dec)nfsd4_decode_verify,
     [OP_OPEN]       = (nfsd4_dec)nfsd4_decode_open,
     [OP_OPENATTR]       = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_OPEN_CONFIRM]   = (nfsd4_dec)nfsd4_decode_open_confirm,
     [OP_OPEN_DOWNGRADE] = (nfsd4_dec)nfsd4_decode_open_downgrade,
     [OP_PUTFH]      = (nfsd4_dec)nfsd4_decode_putfh,
     [OP_PUTPUBFH]       = (nfsd4_dec)nfsd4_decode_putpubfh,
     [OP_PUTROOTFH]      = (nfsd4_dec)nfsd4_decode_noop,
     [OP_READ]       = (nfsd4_dec)nfsd4_decode_read,
     [OP_READDIR]        = (nfsd4_dec)nfsd4_decode_readdir,
     [OP_READLINK]       = (nfsd4_dec)nfsd4_decode_noop,
     [OP_REMOVE]     = (nfsd4_dec)nfsd4_decode_remove,
     [OP_RENAME]     = (nfsd4_dec)nfsd4_decode_rename,
     [OP_RENEW]      = (nfsd4_dec)nfsd4_decode_renew,
     [OP_RESTOREFH]      = (nfsd4_dec)nfsd4_decode_noop,
     [OP_SAVEFH]     = (nfsd4_dec)nfsd4_decode_noop,
     [OP_SECINFO]        = (nfsd4_dec)nfsd4_decode_secinfo,
     [OP_SETATTR]        = (nfsd4_dec)nfsd4_decode_setattr,
     [OP_SETCLIENTID]    = (nfsd4_dec)nfsd4_decode_setclientid,
     [OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
     [OP_VERIFY]     = (nfsd4_dec)nfsd4_decode_verify,
     [OP_WRITE]      = (nfsd4_dec)nfsd4_decode_write,
     [OP_RELEASE_LOCKOWNER]  = (nfsd4_dec)nfsd4_decode_release_lockowner,
 
     /* new operations for NFSv4.1 */
     [OP_BACKCHANNEL_CTL]    = (nfsd4_dec)nfsd4_decode_backchannel_ctl,
     [OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
     [OP_EXCHANGE_ID]    = (nfsd4_dec)nfsd4_decode_exchange_id,
     [OP_CREATE_SESSION] = (nfsd4_dec)nfsd4_decode_create_session,
     [OP_DESTROY_SESSION]    = (nfsd4_dec)nfsd4_decode_destroy_session,
     [OP_FREE_STATEID]   = (nfsd4_dec)nfsd4_decode_free_stateid,
     [OP_GET_DIR_DELEGATION] = (nfsd4_dec)nfsd4_decode_notsupp,
 #ifdef CONFIG_NFSD_PNFS
     [OP_GETDEVICEINFO]  = (nfsd4_dec)nfsd4_decode_getdeviceinfo,
     [OP_GETDEVICELIST]  = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTCOMMIT]   = (nfsd4_dec)nfsd4_decode_layoutcommit,
     [OP_LAYOUTGET]      = (nfsd4_dec)nfsd4_decode_layoutget,
     [OP_LAYOUTRETURN]   = (nfsd4_dec)nfsd4_decode_layoutreturn,
 #else
     [OP_GETDEVICEINFO]  = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_GETDEVICELIST]  = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTCOMMIT]   = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTGET]      = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTRETURN]   = (nfsd4_dec)nfsd4_decode_notsupp,
 #endif
     [OP_SECINFO_NO_NAME]    = (nfsd4_dec)nfsd4_decode_secinfo_no_name,
     [OP_SEQUENCE]       = (nfsd4_dec)nfsd4_decode_sequence,
     [OP_SET_SSV]        = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_TEST_STATEID]   = (nfsd4_dec)nfsd4_decode_test_stateid,
     [OP_WANT_DELEGATION]    = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_DESTROY_CLIENTID]   = (nfsd4_dec)nfsd4_decode_destroy_clientid,
     [OP_RECLAIM_COMPLETE]   = (nfsd4_dec)nfsd4_decode_reclaim_complete,
 
     /* new operations for NFSv4.2 */
     [OP_ALLOCATE]       = (nfsd4_dec)nfsd4_decode_fallocate,
     [OP_COPY]       = (nfsd4_dec)nfsd4_decode_copy,
     [OP_COPY_NOTIFY]    = (nfsd4_dec)nfsd4_decode_copy_notify,
     [OP_DEALLOCATE]     = (nfsd4_dec)nfsd4_decode_fallocate,
     [OP_IO_ADVISE]      = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTERROR]    = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_LAYOUTSTATS]    = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_OFFLOAD_CANCEL] = (nfsd4_dec)nfsd4_decode_offload_status,
     [OP_OFFLOAD_STATUS] = (nfsd4_dec)nfsd4_decode_offload_status,
     [OP_READ_PLUS]      = (nfsd4_dec)nfsd4_decode_read,
     [OP_SEEK]       = (nfsd4_dec)nfsd4_decode_seek,
     [OP_WRITE_SAME]     = (nfsd4_dec)nfsd4_decode_notsupp,
     [OP_CLONE]      = (nfsd4_dec)nfsd4_decode_clone,
     /* RFC 8276 extended atributes operations */
     [OP_GETXATTR]       = (nfsd4_dec)nfsd4_decode_getxattr,
     [OP_SETXATTR]       = (nfsd4_dec)nfsd4_decode_setxattr,
     [OP_LISTXATTRS]     = (nfsd4_dec)nfsd4_decode_listxattrs,
     [OP_REMOVEXATTR]    = (nfsd4_dec)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->opcnt) < 0)
         return false;
 
     /*
      * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
      * here, so we return success at the xdr level so that
      * nfsd4_proc can handle this is an NFS-level error.
      */
     if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
         return true;
 
     if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
         argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
         if (!argp->ops) {
             argp->ops = argp->iops;
             dprintk("nfsd: couldn't allocate room for COMPOUND\n");
             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;
 
         if (xdr_stream_decode_u32(argp->xdr, &op->opnum) < 0)
             return false;
         if (nfsd4_opnum_in_range(argp, 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;
         }
         op->opdesc = OPDESC(op);
         /*
          * 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;
 }
 
 /*
  * 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 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
 {
     *p++ = cpu_to_be32(c->atomic);
     p = xdr_encode_hyper(p, c->before_change);
     p = xdr_encode_hyper(p, c->after_change);
     return p;
 }
 
 /* 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 get_parent_attributes(struct svc_export *exp, struct kstat *stat)
 {
     struct path path = exp->ex_path;
     int err;
 
     path_get(&path);
     while (follow_up(&path)) {
         if (path.dentry != path.mnt->mnt_root)
             break;
     }
     err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
     path_put(&path);
     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;
     }
 
     err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, 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) {
         p = xdr_reserve_space(xdr, 12);
         if (!p)
             goto out_resource;
         p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
         *p++ = cpu_to_be32(stat.atime.tv_nsec);
     }
     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) {
         p = xdr_reserve_space(xdr, 12);
         if (!p)
             goto out_resource;
         p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
         *p++ = cpu_to_be32(stat.ctime.tv_nsec);
     }
     if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
         p = xdr_reserve_space(xdr, 12);
         if (!p)
             goto out_resource;
         p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
         *p++ = cpu_to_be32(stat.mtime.tv_nsec);
     }
     if (bmval1 & FATTR4_WORD1_TIME_CREATE) {
         p = xdr_reserve_space(xdr, 12);
         if (!p)
             goto out_resource;
         p = xdr_encode_hyper(p, (s64)stat.btime.tv_sec);
         *p++ = cpu_to_be32(stat.btime.tv_nsec);
     }
     if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
         struct kstat parent_stat;
         u64 ino = stat.ino;
 
         p = xdr_reserve_space(xdr, 8);
         if (!p)
                     goto out_resource;
         /*
          * Get parent's attributes 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 = get_parent_attributes(exp, &parent_stat);
             if (err)
                 goto out_nfserr;
             ino = parent_stat.ino;
         }
         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_supported_namespace(d_inode(dentry),
                         XATTR_USER_PREFIX);
         *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;
     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_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, struct nfsd4_access *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, struct nfsd4_bind_conn_to_session *bcts)
 {
     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, struct nfsd4_close *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, struct nfsd4_commit *commit)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
     if (!p)
         return nfserr_resource;
     p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
                         NFS4_VERIFIER_SIZE);
     return 0;
 }
 
 static __be32
 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 20);
     if (!p)
         return nfserr_resource;
     encode_cinfo(p, &create->cr_cinfo);
     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, struct nfsd4_getattr *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, struct svc_fh **fhpp)
 {
     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, struct nfsd4_lock *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, struct nfsd4_lockt *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, struct nfsd4_locku *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, struct nfsd4_link *link)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 20);
     if (!p)
         return nfserr_resource;
     p = encode_cinfo(p, &link->li_cinfo);
     return 0;
 }
 
 
 static __be32
 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
     if (nfserr)
         return nfserr;
     p = xdr_reserve_space(xdr, 24);
     if (!p)
         return nfserr_resource;
     p = encode_cinfo(p, &open->op_cinfo);
     *p++ = cpu_to_be32(open->op_rflags);
 
     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, 32);
         if (!p)
             return nfserr_resource;
         *p++ = cpu_to_be32(0);
 
         /*
          * TODO: space_limit's in delegations
          */
         *p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
         *p++ = cpu_to_be32(~(u32)0);
         *p++ = cpu_to_be32(~(u32)0);
 
         /*
          * 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, struct nfsd4_open_confirm *oc)
 {
     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, struct nfsd4_open_downgrade *od)
 {
     struct xdr_stream *xdr = resp->xdr;
 
     return nfsd4_encode_stateid(xdr, &od->od_stateid);
 }
 
 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 will be room for padding if needed */
     if (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;
     status = svc_encode_result_payload(read->rd_rqstp,
                        buf->head[0].iov_len, maxcount);
     if (status) {
         nfserr = nfserrno(status);
         goto out_err;
     }
 
     buf->page_len = maxcount;
     buf->len += maxcount;
     xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
                             / PAGE_SIZE;
 
     /* Use rest of head for padding and remaining ops: */
     buf->tail[0].iov_base = xdr->p;
     buf->tail[0].iov_len = 0;
     xdr->iov = buf->tail;
     if (maxcount&3) {
         int pad = 4 - (maxcount&3);
 
         *(xdr->p++) = 0;
 
         buf->tail[0].iov_base += maxcount&3;
         buf->tail[0].iov_len = pad;
         buf->len += pad;
     }
 
     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 0;
 
 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 starting_len = xdr->buf->len;
     __be32 zero = xdr_zero;
     __be32 nfserr;
 
     read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, maxcount);
     if (read->rd_vlen < 0)
         return nfserr_resource;
 
     nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
                 resp->rqstp->rq_vec, read->rd_vlen, &maxcount,
                 &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,
           struct nfsd4_read *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_resource;
     }
     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, struct nfsd4_readlink *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, struct nfsd4_readdir *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;
 
     p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
     if (!p)
         return nfserr_resource;
 
     /* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
     *p++ = cpu_to_be32(0);
     *p++ = cpu_to_be32(0);
     xdr->buf->head[0].iov_len = (char *)xdr->p -
                     (char *)xdr->buf->head[0].iov_base;
 
     /*
      * 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, struct nfsd4_remove *remove)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 20);
     if (!p)
         return nfserr_resource;
     p = encode_cinfo(p, &remove->rm_cinfo);
     return 0;
 }
 
 static __be32
 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 40);
     if (!p)
         return nfserr_resource;
     p = encode_cinfo(p, &rename->rn_sinfo);
     p = encode_cinfo(p, &rename->rn_tinfo);
     return 0;
 }
 
 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,
              struct nfsd4_secinfo *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,
              struct nfsd4_secinfo_no_name *secinfo)
 {
     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, struct nfsd4_setattr *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, struct nfsd4_setclientid *scd)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     if (!nfserr) {
         p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
         if (!p)
             return nfserr_resource;
         p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
         p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
                         NFS4_VERIFIER_SIZE);
     }
     else if (nfserr == nfserr_clid_inuse) {
         p = xdr_reserve_space(xdr, 8);
         if (!p)
             return nfserr_resource;
         *p++ = cpu_to_be32(0);
         *p++ = cpu_to_be32(0);
     }
     return nfserr;
 }
 
 static __be32
 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 16);
     if (!p)
         return nfserr_resource;
     *p++ = cpu_to_be32(write->wr_bytes_written);
     *p++ = cpu_to_be32(write->wr_how_written);
     p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
                         NFS4_VERIFIER_SIZE);
     return 0;
 }
 
 static __be32
 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
              struct nfsd4_exchange_id *exid)
 {
     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);
 
     p = xdr_reserve_space(xdr,
         8 /* eir_clientid */ +
         4 /* eir_sequenceid */ +
         4 /* eir_flags */ +
         4 /* spr_how */);
     if (!p)
         return nfserr_resource;
 
     p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
     *p++ = cpu_to_be32(exid->seqid);
     *p++ = cpu_to_be32(exid->flags);
 
     *p++ = cpu_to_be32(exid->spa_how);
 
     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,
                 struct nfsd4_create_session *sess)
 {
     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,
               struct nfsd4_sequence *seq)
 {
     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,
               struct nfsd4_test_stateid *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,
         struct nfsd4_getdeviceinfo *gdev)
 {
     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);
 
     /* If maxcount is 0 then just update notifications */
     if (gdev->gd_maxcount != 0) {
         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,
         struct nfsd4_layoutget *lgp)
 {
     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,
               struct nfsd4_layoutcommit *lcp)
 {
     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,
         struct nfsd4_layoutreturn *lrp)
 {
     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,
           struct nfsd4_copy *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,
                 struct nfsd4_offload_status *os)
 {
     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,
                 unsigned long *maxcount, u32 *eof,
                 loff_t *pos)
 {
     struct xdr_stream *xdr = resp->xdr;
     struct file *file = read->rd_nf->nf_file;
     int starting_len = xdr->buf->len;
     loff_t hole_pos;
     __be32 nfserr;
     __be32 *p, tmp;
     __be64 tmp64;
 
     hole_pos = pos ? *pos : vfs_llseek(file, read->rd_offset, SEEK_HOLE);
     if (hole_pos > read->rd_offset)
         *maxcount = min_t(unsigned long, *maxcount, hole_pos - read->rd_offset);
     *maxcount = min_t(unsigned long, *maxcount, (xdr->buf->buflen - xdr->buf->len));
 
     /* Content type, offset, byte count */
     p = xdr_reserve_space(xdr, 4 + 8 + 4);
     if (!p)
         return nfserr_resource;
 
     read->rd_vlen = xdr_reserve_space_vec(xdr, resp->rqstp->rq_vec, *maxcount);
     if (read->rd_vlen < 0)
         return nfserr_resource;
 
     nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
                 resp->rqstp->rq_vec, read->rd_vlen, maxcount, eof);
     if (nfserr)
         return nfserr;
     xdr_truncate_encode(xdr, starting_len + 16 + xdr_align_size(*maxcount));
 
     tmp = htonl(NFS4_CONTENT_DATA);
     write_bytes_to_xdr_buf(xdr->buf, starting_len,      &tmp,   4);
     tmp64 = cpu_to_be64(read->rd_offset);
     write_bytes_to_xdr_buf(xdr->buf, starting_len + 4,  &tmp64, 8);
     tmp = htonl(*maxcount);
     write_bytes_to_xdr_buf(xdr->buf, starting_len + 12, &tmp,   4);
 
     tmp = xdr_zero;
     write_bytes_to_xdr_buf(xdr->buf, starting_len + 16 + *maxcount, &tmp,
                    xdr_pad_size(*maxcount));
     return nfs_ok;
 }
 
 static __be32
 nfsd4_encode_read_plus_hole(struct nfsd4_compoundres *resp,
                 struct nfsd4_read *read,
                 unsigned long *maxcount, u32 *eof)
 {
     struct file *file = read->rd_nf->nf_file;
     loff_t data_pos = vfs_llseek(file, read->rd_offset, SEEK_DATA);
     loff_t f_size = i_size_read(file_inode(file));
     unsigned long count;
     __be32 *p;
 
     if (data_pos == -ENXIO)
         data_pos = f_size;
     else if (data_pos <= read->rd_offset || (data_pos < f_size && data_pos % PAGE_SIZE))
         return nfsd4_encode_read_plus_data(resp, read, maxcount, eof, &f_size);
     count = data_pos - read->rd_offset;
 
     /* Content type, offset, byte count */
     p = xdr_reserve_space(resp->xdr, 4 + 8 + 8);
     if (!p)
         return nfserr_resource;
 
     *p++ = htonl(NFS4_CONTENT_HOLE);
     p = xdr_encode_hyper(p, read->rd_offset);
     p = xdr_encode_hyper(p, count);
 
     *eof = (read->rd_offset + count) >= f_size;
     *maxcount = min_t(unsigned long, count, *maxcount);
     return nfs_ok;
 }
 
 static __be32
 nfsd4_encode_read_plus(struct nfsd4_compoundres *resp, __be32 nfserr,
                struct nfsd4_read *read)
 {
     unsigned long maxcount, count;
     struct xdr_stream *xdr = resp->xdr;
     struct file *file;
     int starting_len = xdr->buf->len;
     int last_segment = xdr->buf->len;
     int segments = 0;
     __be32 *p, tmp;
     bool is_data;
     loff_t pos;
     u32 eof;
 
     if (nfserr)
         return nfserr;
     file = read->rd_nf->nf_file;
 
     /* eof flag, segment count */
     p = xdr_reserve_space(xdr, 4 + 4);
     if (!p)
         return nfserr_resource;
     xdr_commit_encode(xdr);
 
     maxcount = min_t(unsigned long, read->rd_length,
              (xdr->buf->buflen - xdr->buf->len));
     count    = maxcount;
 
     eof = read->rd_offset >= i_size_read(file_inode(file));
     if (eof)
         goto out;
 
     pos = vfs_llseek(file, read->rd_offset, SEEK_HOLE);
     is_data = pos > read->rd_offset;
 
     while (count > 0 && !eof) {
         maxcount = count;
         if (is_data)
             nfserr = nfsd4_encode_read_plus_data(resp, read, &maxcount, &eof,
                         segments == 0 ? &pos : NULL);
         else
             nfserr = nfsd4_encode_read_plus_hole(resp, read, &maxcount, &eof);
         if (nfserr)
             goto out;
         count -= maxcount;
         read->rd_offset += maxcount;
         is_data = !is_data;
         last_segment = xdr->buf->len;
         segments++;
     }
 
 out:
     if (nfserr && segments == 0)
         xdr_truncate_encode(xdr, starting_len);
     else {
         if (nfserr) {
             xdr_truncate_encode(xdr, last_segment);
             nfserr = nfs_ok;
             eof = 0;
         }
         tmp = htonl(eof);
         write_bytes_to_xdr_buf(xdr->buf, starting_len,     &tmp, 4);
         tmp = htonl(segments);
         write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
     }
 
     return nfserr;
 }
 
 static __be32
 nfsd4_encode_copy_notify(struct nfsd4_compoundres *resp, __be32 nfserr,
              struct nfsd4_copy_notify *cn)
 {
     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,
           struct nfsd4_seek *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, void *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,
               struct nfsd4_getxattr *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,
               struct nfsd4_setxattr *setxattr)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 20);
     if (!p)
         return nfserr_resource;
 
     encode_cinfo(p, &setxattr->setxa_cinfo);
 
     return 0;
 }
 
 /*
  * 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,
             struct nfsd4_listxattrs *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,
              struct nfsd4_removexattr *removexattr)
 {
     struct xdr_stream *xdr = resp->xdr;
     __be32 *p;
 
     p = xdr_reserve_space(xdr, 20);
     if (!p)
         return nfserr_resource;
 
     p = encode_cinfo(p, &removexattr->rmxa_cinfo);
     return 0;
 }
 
 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
 
 /*
  * 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_enc)nfsd4_encode_access,
     [OP_CLOSE]      = (nfsd4_enc)nfsd4_encode_close,
     [OP_COMMIT]     = (nfsd4_enc)nfsd4_encode_commit,
     [OP_CREATE]     = (nfsd4_enc)nfsd4_encode_create,
     [OP_DELEGPURGE]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_DELEGRETURN]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_GETATTR]        = (nfsd4_enc)nfsd4_encode_getattr,
     [OP_GETFH]      = (nfsd4_enc)nfsd4_encode_getfh,
     [OP_LINK]       = (nfsd4_enc)nfsd4_encode_link,
     [OP_LOCK]       = (nfsd4_enc)nfsd4_encode_lock,
     [OP_LOCKT]      = (nfsd4_enc)nfsd4_encode_lockt,
     [OP_LOCKU]      = (nfsd4_enc)nfsd4_encode_locku,
     [OP_LOOKUP]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LOOKUPP]        = (nfsd4_enc)nfsd4_encode_noop,
     [OP_NVERIFY]        = (nfsd4_enc)nfsd4_encode_noop,
     [OP_OPEN]       = (nfsd4_enc)nfsd4_encode_open,
     [OP_OPENATTR]       = (nfsd4_enc)nfsd4_encode_noop,
     [OP_OPEN_CONFIRM]   = (nfsd4_enc)nfsd4_encode_open_confirm,
     [OP_OPEN_DOWNGRADE] = (nfsd4_enc)nfsd4_encode_open_downgrade,
     [OP_PUTFH]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_PUTPUBFH]       = (nfsd4_enc)nfsd4_encode_noop,
     [OP_PUTROOTFH]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_READ]       = (nfsd4_enc)nfsd4_encode_read,
     [OP_READDIR]        = (nfsd4_enc)nfsd4_encode_readdir,
     [OP_READLINK]       = (nfsd4_enc)nfsd4_encode_readlink,
     [OP_REMOVE]     = (nfsd4_enc)nfsd4_encode_remove,
     [OP_RENAME]     = (nfsd4_enc)nfsd4_encode_rename,
     [OP_RENEW]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_RESTOREFH]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_SAVEFH]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_SECINFO]        = (nfsd4_enc)nfsd4_encode_secinfo,
     [OP_SETATTR]        = (nfsd4_enc)nfsd4_encode_setattr,
     [OP_SETCLIENTID]    = (nfsd4_enc)nfsd4_encode_setclientid,
     [OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
     [OP_VERIFY]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_WRITE]      = (nfsd4_enc)nfsd4_encode_write,
     [OP_RELEASE_LOCKOWNER]  = (nfsd4_enc)nfsd4_encode_noop,
 
     /* NFSv4.1 operations */
     [OP_BACKCHANNEL_CTL]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
     [OP_EXCHANGE_ID]    = (nfsd4_enc)nfsd4_encode_exchange_id,
     [OP_CREATE_SESSION] = (nfsd4_enc)nfsd4_encode_create_session,
     [OP_DESTROY_SESSION]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_FREE_STATEID]   = (nfsd4_enc)nfsd4_encode_noop,
     [OP_GET_DIR_DELEGATION] = (nfsd4_enc)nfsd4_encode_noop,
 #ifdef CONFIG_NFSD_PNFS
     [OP_GETDEVICEINFO]  = (nfsd4_enc)nfsd4_encode_getdeviceinfo,
     [OP_GETDEVICELIST]  = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTCOMMIT]   = (nfsd4_enc)nfsd4_encode_layoutcommit,
     [OP_LAYOUTGET]      = (nfsd4_enc)nfsd4_encode_layoutget,
     [OP_LAYOUTRETURN]   = (nfsd4_enc)nfsd4_encode_layoutreturn,
 #else
     [OP_GETDEVICEINFO]  = (nfsd4_enc)nfsd4_encode_noop,
     [OP_GETDEVICELIST]  = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTCOMMIT]   = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTGET]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTRETURN]   = (nfsd4_enc)nfsd4_encode_noop,
 #endif
     [OP_SECINFO_NO_NAME]    = (nfsd4_enc)nfsd4_encode_secinfo_no_name,
     [OP_SEQUENCE]       = (nfsd4_enc)nfsd4_encode_sequence,
     [OP_SET_SSV]        = (nfsd4_enc)nfsd4_encode_noop,
     [OP_TEST_STATEID]   = (nfsd4_enc)nfsd4_encode_test_stateid,
     [OP_WANT_DELEGATION]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_DESTROY_CLIENTID]   = (nfsd4_enc)nfsd4_encode_noop,
     [OP_RECLAIM_COMPLETE]   = (nfsd4_enc)nfsd4_encode_noop,
 
     /* NFSv4.2 operations */
     [OP_ALLOCATE]       = (nfsd4_enc)nfsd4_encode_noop,
     [OP_COPY]       = (nfsd4_enc)nfsd4_encode_copy,
     [OP_COPY_NOTIFY]    = (nfsd4_enc)nfsd4_encode_copy_notify,
     [OP_DEALLOCATE]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_IO_ADVISE]      = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTERROR]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_LAYOUTSTATS]    = (nfsd4_enc)nfsd4_encode_noop,
     [OP_OFFLOAD_CANCEL] = (nfsd4_enc)nfsd4_encode_noop,
     [OP_OFFLOAD_STATUS] = (nfsd4_enc)nfsd4_encode_offload_status,
     [OP_READ_PLUS]      = (nfsd4_enc)nfsd4_encode_read_plus,
     [OP_SEEK]       = (nfsd4_enc)nfsd4_encode_seek,
     [OP_WRITE_SAME]     = (nfsd4_enc)nfsd4_encode_noop,
     [OP_CLONE]      = (nfsd4_enc)nfsd4_encode_noop,
 
     /* RFC 8276 extended atributes operations */
     [OP_GETXATTR]       = (nfsd4_enc)nfsd4_encode_getxattr,
     [OP_SETXATTR]       = (nfsd4_enc)nfsd4_encode_setxattr,
     [OP_LISTXATTRS]     = (nfsd4_enc)nfsd4_encode_listxattrs,
     [OP_REMOVEXATTR]    = (nfsd4_enc)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) {
         WARN_ON_ONCE(1);
         return;
     }
     *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);
     if (opdesc && opdesc->op_release)
         opdesc->op_release(&op->u);
     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;
 }
 
 /* 
  * 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) {
         kfree(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;
     struct xdr_buf *buf = xdr->buf;
     __be32 *p;
 
     WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
                  buf->tail[0].iov_len);
 
     /*
      * Send buffer space for the following items is reserved
      * at the top of nfsd4_proc_compound().
      */
     p = resp->statusp;
 
     *p++ = resp->cstate.status;
 
     rqstp->rq_next_page = xdr->page_ptr + 1;
 
     *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;
 }