[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry

[mirror_ubuntu-artful-kernel.git] / fs / nfsd / nfs4xdr.c

/*
 *  fs/nfs/nfs4xdr.c
 *
 *  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.
 *
 * TODO: Neil Brown made the following observation:  We currently
 * initially reserve NFSD_BUFSIZE space on the transmit queue and
 * never release any of that until the request is complete.
 * It would be good to calculate a new maximum response size while
 * decoding the COMPOUND, and call svc_reserve with this number
 * at the end of nfs4svc_decode_compoundargs.
 */

#include <linux/param.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/vfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/state.h>
#include <linux/nfsd/xdr4.h>
#include <linux/nfsd_idmap.h>
#include <linux/nfs4.h>
#include <linux/nfs4_acl.h>

#define NFSDDBG_FACILITY                NFSDDBG_XDR

static int
check_filename(char *str, int len, int err)
{
        int i;

        if (len == 0)
                return nfserr_inval;
        if (isdotent(str, len))
                return err;
        for (i = 0; i < len; i++)
                if (str[i] == '/')
                        return err;
        return 0;
}

/*
 * START OF "GENERIC" DECODE ROUTINES.
 *   These may look a little ugly since they are imported from a "generic"
 * set of XDR encode/decode routines which are intended to be shared by
 * all of our NFSv4 implementations (OpenBSD, MacOS X...).
 *
 * If the pain of reading these is too great, it should be a straightforward
 * task to translate them into Linux-specific versions which are more
 * consistent with the style used in NFSv2/v3...
 */
#define DECODE_HEAD                             \
        u32 *p;                                 \
        int status
#define DECODE_TAIL                             \
        status = 0;                             \
out:                                            \
        return status;                          \
xdr_error:                                      \
        printk(KERN_NOTICE "xdr error! (%s:%d)\n", __FILE__, __LINE__); \
        status = nfserr_bad_xdr;                \
        goto out

#define READ32(x)         (x) = ntohl(*p++)
#define READ64(x)         do {                  \
        (x) = (u64)ntohl(*p++) << 32;           \
        (x) |= ntohl(*p++);                     \
} while (0)
#define READTIME(x)       do {                  \
        p++;                                    \
        (x) = ntohl(*p++);                      \
        p++;                                    \
} while (0)
#define READMEM(x,nbytes) do {                  \
        x = (char *)p;                          \
        p += XDR_QUADLEN(nbytes);               \
} while (0)
#define SAVEMEM(x,nbytes) do {                  \
        if (!(x = (p==argp->tmp || p == argp->tmpp) ? \
                savemem(argp, p, nbytes) :      \
                (char *)p)) {                   \
                printk(KERN_NOTICE "xdr error! (%s:%d)\n", __FILE__, __LINE__); \
                goto xdr_error;                 \
                }                               \
        p += XDR_QUADLEN(nbytes);               \
} while (0)
#define COPYMEM(x,nbytes) do {                  \
        memcpy((x), p, nbytes);                 \
        p += XDR_QUADLEN(nbytes);               \
} while (0)

/* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
#define READ_BUF(nbytes)  do {                  \
        if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) {     \
                p = argp->p;                    \
                argp->p += XDR_QUADLEN(nbytes); \
        } else if (!(p = read_buf(argp, nbytes))) { \
                printk(KERN_NOTICE "xdr error! (%s:%d)\n", __FILE__, __LINE__); \
                goto xdr_error;                 \
        }                                       \
} while (0)

static u32 *read_buf(struct nfsd4_compoundargs *argp, int nbytes)
{
        /* We want more bytes than seem to be available.
         * Maybe we need a new page, maybe we have just run out
         */
        int avail = (char*)argp->end - (char*)argp->p;
        u32 *p;
        if (avail + argp->pagelen < nbytes)
                return NULL;
        if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
                return NULL;
        /* ok, we can do it with the current plus the next page */
        if (nbytes <= sizeof(argp->tmp))
                p = argp->tmp;
        else {
                kfree(argp->tmpp);
                p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
                if (!p)
                        return NULL;
                
        }
        memcpy(p, argp->p, avail);
        /* step to next page */
        argp->p = page_address(argp->pagelist[0]);
        argp->pagelist++;
        if (argp->pagelen < PAGE_SIZE) {
                argp->end = p + (argp->pagelen>>2);
                argp->pagelen = 0;
        } else {
                argp->end = p + (PAGE_SIZE>>2);
                argp->pagelen -= PAGE_SIZE;
        }
        memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
        argp->p += XDR_QUADLEN(nbytes - avail);
        return p;
}

static int
defer_free(struct nfsd4_compoundargs *argp,
                void (*release)(const void *), void *p)
{
        struct tmpbuf *tb;

        tb = kmalloc(sizeof(*tb), GFP_KERNEL);
        if (!tb)
                return -ENOMEM;
        tb->buf = p;
        tb->release = release;
        tb->next = argp->to_free;
        argp->to_free = tb;
        return 0;
}

static char *savemem(struct nfsd4_compoundargs *argp, u32 *p, int nbytes)
{
        void *new = NULL;
        if (p == argp->tmp) {
                new = kmalloc(nbytes, GFP_KERNEL);
                if (!new) return NULL;
                p = new;
                memcpy(p, argp->tmp, nbytes);
        } else {
                if (p != argp->tmpp)
                        BUG();
                argp->tmpp = NULL;
        }
        if (defer_free(argp, kfree, p)) {
                kfree(new);
                return NULL;
        } else
                return (char *)p;
}


static int
nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
{
        u32 bmlen;
        DECODE_HEAD;

        bmval[0] = 0;
        bmval[1] = 0;

        READ_BUF(4);
        READ32(bmlen);
        if (bmlen > 1000)
                goto xdr_error;

        READ_BUF(bmlen << 2);
        if (bmlen > 0)
                READ32(bmval[0]);
        if (bmlen > 1)
                READ32(bmval[1]);

        DECODE_TAIL;
}

static int
nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval, struct iattr *iattr,
    struct nfs4_acl **acl)
{
        int expected_len, len = 0;
        u32 dummy32;
        char *buf;

        DECODE_HEAD;
        iattr->ia_valid = 0;
        if ((status = nfsd4_decode_bitmap(argp, bmval)))
                return status;

        /*
         * According to spec, unsupported attributes return ERR_NOTSUPP;
         * read-only attributes return ERR_INVAL.
         */
        if ((bmval[0] & ~NFSD_SUPPORTED_ATTRS_WORD0) || (bmval[1] & ~NFSD_SUPPORTED_ATTRS_WORD1))
                return nfserr_attrnotsupp;
        if ((bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0) || (bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1))
                return nfserr_inval;

        READ_BUF(4);
        READ32(expected_len);

        if (bmval[0] & FATTR4_WORD0_SIZE) {
                READ_BUF(8);
                len += 8;
                READ64(iattr->ia_size);
                iattr->ia_valid |= ATTR_SIZE;
        }
        if (bmval[0] & FATTR4_WORD0_ACL) {
                int nace, i;
                struct nfs4_ace ace;

                READ_BUF(4); len += 4;
                READ32(nace);

                *acl = nfs4_acl_new();
                if (*acl == NULL) {
                        status = -ENOMEM;
                        goto out_nfserr;
                }
                defer_free(argp, (void (*)(const void *))nfs4_acl_free, *acl);

                for (i = 0; i < nace; i++) {
                        READ_BUF(16); len += 16;
                        READ32(ace.type);
                        READ32(ace.flag);
                        READ32(ace.access_mask);
                        READ32(dummy32);
                        READ_BUF(dummy32);
                        len += XDR_QUADLEN(dummy32) << 2;
                        READMEM(buf, dummy32);
                        ace.whotype = nfs4_acl_get_whotype(buf, dummy32);
                        status = 0;
                        if (ace.whotype != NFS4_ACL_WHO_NAMED)
                                ace.who = 0;
                        else if (ace.flag & NFS4_ACE_IDENTIFIER_GROUP)
                                status = nfsd_map_name_to_gid(argp->rqstp,
                                                buf, dummy32, &ace.who);
                        else
                                status = nfsd_map_name_to_uid(argp->rqstp,
                                                buf, dummy32, &ace.who);
                        if (status)
                                goto out_nfserr;
                        status = nfs4_acl_add_ace(*acl, ace.type, ace.flag,
                                 ace.access_mask, ace.whotype, ace.who);
                        if (status)
                                goto out_nfserr;
                }
        } else
                *acl = NULL;
        if (bmval[1] & FATTR4_WORD1_MODE) {
                READ_BUF(4);
                len += 4;
                READ32(iattr->ia_mode);
                iattr->ia_mode &= (S_IFMT | S_IALLUGO);
                iattr->ia_valid |= ATTR_MODE;
        }
        if (bmval[1] & FATTR4_WORD1_OWNER) {
                READ_BUF(4);
                len += 4;
                READ32(dummy32);
                READ_BUF(dummy32);
                len += (XDR_QUADLEN(dummy32) << 2);
                READMEM(buf, dummy32);
                if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid)))
                        goto out_nfserr;
                iattr->ia_valid |= ATTR_UID;
        }
        if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
                READ_BUF(4);
                len += 4;
                READ32(dummy32);
                READ_BUF(dummy32);
                len += (XDR_QUADLEN(dummy32) << 2);
                READMEM(buf, dummy32);
                if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid)))
                        goto out_nfserr;
                iattr->ia_valid |= ATTR_GID;
        }
        if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
                READ_BUF(4);
                len += 4;
                READ32(dummy32);
                switch (dummy32) {
                case NFS4_SET_TO_CLIENT_TIME:
                        /* We require the high 32 bits of 'seconds' to be 0, and we ignore
                           all 32 bits of 'nseconds'. */
                        READ_BUF(12);
                        len += 12;
                        READ32(dummy32);
                        if (dummy32)
                                return nfserr_inval;
                        READ32(iattr->ia_atime.tv_sec);
                        READ32(iattr->ia_atime.tv_nsec);
                        if (iattr->ia_atime.tv_nsec >= (u32)1000000000)
                                return nfserr_inval;
                        iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
                        break;
                case NFS4_SET_TO_SERVER_TIME:
                        iattr->ia_valid |= ATTR_ATIME;
                        break;
                default:
                        goto xdr_error;
                }
        }
        if (bmval[1] & FATTR4_WORD1_TIME_METADATA) {
                /* We require the high 32 bits of 'seconds' to be 0, and we ignore
                   all 32 bits of 'nseconds'. */
                READ_BUF(12);
                len += 12;
                READ32(dummy32);
                if (dummy32)
                        return nfserr_inval;
                READ32(iattr->ia_ctime.tv_sec);
                READ32(iattr->ia_ctime.tv_nsec);
                if (iattr->ia_ctime.tv_nsec >= (u32)1000000000)
                        return nfserr_inval;
                iattr->ia_valid |= ATTR_CTIME;
        }
        if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
                READ_BUF(4);
                len += 4;
                READ32(dummy32);
                switch (dummy32) {
                case NFS4_SET_TO_CLIENT_TIME:
                        /* We require the high 32 bits of 'seconds' to be 0, and we ignore
                           all 32 bits of 'nseconds'. */
                        READ_BUF(12);
                        len += 12;
                        READ32(dummy32);
                        if (dummy32)
                                return nfserr_inval;
                        READ32(iattr->ia_mtime.tv_sec);
                        READ32(iattr->ia_mtime.tv_nsec);
                        if (iattr->ia_mtime.tv_nsec >= (u32)1000000000)
                                return nfserr_inval;
                        iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
                        break;
                case NFS4_SET_TO_SERVER_TIME:
                        iattr->ia_valid |= ATTR_MTIME;
                        break;
                default:
                        goto xdr_error;
                }
        }
        if (len != expected_len)
                goto xdr_error;

        DECODE_TAIL;

out_nfserr:
        status = nfserrno(status);
        goto out;
}

static int
nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(access->ac_req_access);

        DECODE_TAIL;
}

static int
nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
{
        DECODE_HEAD;

        close->cl_stateowner = NULL;
        READ_BUF(4 + sizeof(stateid_t));
        READ32(close->cl_seqid);
        READ32(close->cl_stateid.si_generation);
        COPYMEM(&close->cl_stateid.si_opaque, sizeof(stateid_opaque_t));

        DECODE_TAIL;
}


static int
nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
{
        DECODE_HEAD;

        READ_BUF(12);
        READ64(commit->co_offset);
        READ32(commit->co_count);

        DECODE_TAIL;
}

static int
nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(create->cr_type);
        switch (create->cr_type) {
        case NF4LNK:
                READ_BUF(4);
                READ32(create->cr_linklen);
                READ_BUF(create->cr_linklen);
                SAVEMEM(create->cr_linkname, create->cr_linklen);
                break;
        case NF4BLK:
        case NF4CHR:
                READ_BUF(8);
                READ32(create->cr_specdata1);
                READ32(create->cr_specdata2);
                break;
        case NF4SOCK:
        case NF4FIFO:
        case NF4DIR:
        default:
                break;
        }

        READ_BUF(4);
        READ32(create->cr_namelen);
        READ_BUF(create->cr_namelen);
        SAVEMEM(create->cr_name, create->cr_namelen);
        if ((status = check_filename(create->cr_name, create->cr_namelen, nfserr_inval)))
                return status;

        if ((status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr, &create->cr_acl)))
                goto out;

        DECODE_TAIL;
}

static inline int
nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
{
        DECODE_HEAD;

        READ_BUF(sizeof(stateid_t));
        READ32(dr->dr_stateid.si_generation);
        COPYMEM(&dr->dr_stateid.si_opaque, sizeof(stateid_opaque_t));

        DECODE_TAIL;
}

static inline int
nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
{
        return nfsd4_decode_bitmap(argp, getattr->ga_bmval);
}

static int
nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(link->li_namelen);
        READ_BUF(link->li_namelen);
        SAVEMEM(link->li_name, link->li_namelen);
        if ((status = check_filename(link->li_name, link->li_namelen, nfserr_inval)))
                return status;

        DECODE_TAIL;
}

static int
nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
{
        DECODE_HEAD;

        lock->lk_replay_owner = NULL;
        /*
        * type, reclaim(boolean), offset, length, new_lock_owner(boolean)
        */
        READ_BUF(28);
        READ32(lock->lk_type);
        if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
                goto xdr_error;
        READ32(lock->lk_reclaim);
        READ64(lock->lk_offset);
        READ64(lock->lk_length);
        READ32(lock->lk_is_new);

        if (lock->lk_is_new) {
                READ_BUF(36);
                READ32(lock->lk_new_open_seqid);
                READ32(lock->lk_new_open_stateid.si_generation);

                COPYMEM(&lock->lk_new_open_stateid.si_opaque, sizeof(stateid_opaque_t));
                READ32(lock->lk_new_lock_seqid);
                COPYMEM(&lock->lk_new_clientid, sizeof(clientid_t));
                READ32(lock->lk_new_owner.len);
                READ_BUF(lock->lk_new_owner.len);
                READMEM(lock->lk_new_owner.data, lock->lk_new_owner.len);
        } else {
                READ_BUF(20);
                READ32(lock->lk_old_lock_stateid.si_generation);
                COPYMEM(&lock->lk_old_lock_stateid.si_opaque, sizeof(stateid_opaque_t));
                READ32(lock->lk_old_lock_seqid);
        }

        DECODE_TAIL;
}

static int
nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
{
        DECODE_HEAD;
                        
        READ_BUF(32);
        READ32(lockt->lt_type);
        if((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
                goto xdr_error;
        READ64(lockt->lt_offset);
        READ64(lockt->lt_length);
        COPYMEM(&lockt->lt_clientid, 8);
        READ32(lockt->lt_owner.len);
        READ_BUF(lockt->lt_owner.len);
        READMEM(lockt->lt_owner.data, lockt->lt_owner.len);

        DECODE_TAIL;
}

static int
nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
{
        DECODE_HEAD;

        locku->lu_stateowner = NULL;
        READ_BUF(24 + sizeof(stateid_t));
        READ32(locku->lu_type);
        if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
                goto xdr_error;
        READ32(locku->lu_seqid);
        READ32(locku->lu_stateid.si_generation);
        COPYMEM(&locku->lu_stateid.si_opaque, sizeof(stateid_opaque_t));
        READ64(locku->lu_offset);
        READ64(locku->lu_length);

        DECODE_TAIL;
}

static int
nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(lookup->lo_len);
        READ_BUF(lookup->lo_len);
        SAVEMEM(lookup->lo_name, lookup->lo_len);
        if ((status = check_filename(lookup->lo_name, lookup->lo_len, nfserr_noent)))
                return status;

        DECODE_TAIL;
}

static int
nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
{
        DECODE_HEAD;

        memset(open->op_bmval, 0, sizeof(open->op_bmval));
        open->op_iattr.ia_valid = 0;
        open->op_stateowner = NULL;

        /* seqid, share_access, share_deny, clientid, ownerlen */
        READ_BUF(16 + sizeof(clientid_t));
        READ32(open->op_seqid);
        READ32(open->op_share_access);
        READ32(open->op_share_deny);
        COPYMEM(&open->op_clientid, sizeof(clientid_t));
        READ32(open->op_owner.len);

        /* owner, open_flag */
        READ_BUF(open->op_owner.len + 4);
        SAVEMEM(open->op_owner.data, open->op_owner.len);
        READ32(open->op_create);
        switch (open->op_create) {
        case NFS4_OPEN_NOCREATE:
                break;
        case NFS4_OPEN_CREATE:
                READ_BUF(4);
                READ32(open->op_createmode);
                switch (open->op_createmode) {
                case NFS4_CREATE_UNCHECKED:
                case NFS4_CREATE_GUARDED:
                        if ((status = nfsd4_decode_fattr(argp, open->op_bmval, &open->op_iattr, &open->op_acl)))
                                goto out;
                        break;
                case NFS4_CREATE_EXCLUSIVE:
                        READ_BUF(8);
                        COPYMEM(open->op_verf.data, 8);
                        break;
                default:
                        goto xdr_error;
                }
                break;
        default:
                goto xdr_error;
        }

        /* open_claim */
        READ_BUF(4);
        READ32(open->op_claim_type);
        switch (open->op_claim_type) {
        case NFS4_OPEN_CLAIM_NULL:
        case NFS4_OPEN_CLAIM_DELEGATE_PREV:
                READ_BUF(4);
                READ32(open->op_fname.len);
                READ_BUF(open->op_fname.len);
                SAVEMEM(open->op_fname.data, open->op_fname.len);
                if ((status = check_filename(open->op_fname.data, open->op_fname.len, nfserr_inval)))
                        return status;
                break;
        case NFS4_OPEN_CLAIM_PREVIOUS:
                READ_BUF(4);
                READ32(open->op_delegate_type);
                break;
        case NFS4_OPEN_CLAIM_DELEGATE_CUR:
                READ_BUF(sizeof(stateid_t) + 4);
                COPYMEM(&open->op_delegate_stateid, sizeof(stateid_t));
                READ32(open->op_fname.len);
                READ_BUF(open->op_fname.len);
                SAVEMEM(open->op_fname.data, open->op_fname.len);
                if ((status = check_filename(open->op_fname.data, open->op_fname.len, nfserr_inval)))
                        return status;
                break;
        default:
                goto xdr_error;
        }

        DECODE_TAIL;
}

static int
nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
{
        DECODE_HEAD;
                    
        open_conf->oc_stateowner = NULL;
        READ_BUF(4 + sizeof(stateid_t));
        READ32(open_conf->oc_req_stateid.si_generation);
        COPYMEM(&open_conf->oc_req_stateid.si_opaque, sizeof(stateid_opaque_t));
        READ32(open_conf->oc_seqid);
                                                        
        DECODE_TAIL;
}

static int
nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
{
        DECODE_HEAD;
                    
        open_down->od_stateowner = NULL;
        READ_BUF(12 + sizeof(stateid_t));
        READ32(open_down->od_stateid.si_generation);
        COPYMEM(&open_down->od_stateid.si_opaque, sizeof(stateid_opaque_t));
        READ32(open_down->od_seqid);
        READ32(open_down->od_share_access);
        READ32(open_down->od_share_deny);
                                                        
        DECODE_TAIL;
}

static int
nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(putfh->pf_fhlen);
        if (putfh->pf_fhlen > NFS4_FHSIZE)
                goto xdr_error;
        READ_BUF(putfh->pf_fhlen);
        SAVEMEM(putfh->pf_fhval, putfh->pf_fhlen);

        DECODE_TAIL;
}

static int
nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
{
        DECODE_HEAD;

        READ_BUF(sizeof(stateid_t) + 12);
        READ32(read->rd_stateid.si_generation);
        COPYMEM(&read->rd_stateid.si_opaque, sizeof(stateid_opaque_t));
        READ64(read->rd_offset);
        READ32(read->rd_length);

        DECODE_TAIL;
}

static int
nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
{
        DECODE_HEAD;

        READ_BUF(24);
        READ64(readdir->rd_cookie);
        COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
        READ32(readdir->rd_dircount);    /* just in case you needed a useless field... */
        READ32(readdir->rd_maxcount);
        if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
                goto out;

        DECODE_TAIL;
}

static int
nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(remove->rm_namelen);
        READ_BUF(remove->rm_namelen);
        SAVEMEM(remove->rm_name, remove->rm_namelen);
        if ((status = check_filename(remove->rm_name, remove->rm_namelen, nfserr_noent)))
                return status;

        DECODE_TAIL;
}

static int
nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
{
        DECODE_HEAD;

        READ_BUF(4);
        READ32(rename->rn_snamelen);
        READ_BUF(rename->rn_snamelen + 4);
        SAVEMEM(rename->rn_sname, rename->rn_snamelen);
        READ32(rename->rn_tnamelen);
        READ_BUF(rename->rn_tnamelen);
        SAVEMEM(rename->rn_tname, rename->rn_tnamelen);
        if ((status = check_filename(rename->rn_sname, rename->rn_snamelen, nfserr_noent)))
                return status;
        if ((status = check_filename(rename->rn_tname, rename->rn_tnamelen, nfserr_inval)))
                return status;

        DECODE_TAIL;
}

static int
nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
{
        DECODE_HEAD;

        READ_BUF(sizeof(clientid_t));
        COPYMEM(clientid, sizeof(clientid_t));

        DECODE_TAIL;
}

static int
nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
{
        DECODE_HEAD;

        READ_BUF(sizeof(stateid_t));
        READ32(setattr->sa_stateid.si_generation);
        COPYMEM(&setattr->sa_stateid.si_opaque, sizeof(stateid_opaque_t));
        if ((status = nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr, &setattr->sa_acl)))
                goto out;

        DECODE_TAIL;
}

static int
nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
{
        DECODE_HEAD;

        READ_BUF(12);
        COPYMEM(setclientid->se_verf.data, 8);
        READ32(setclientid->se_namelen);

        READ_BUF(setclientid->se_namelen + 8);
        SAVEMEM(setclientid->se_name, setclientid->se_namelen);
        READ32(setclientid->se_callback_prog);
        READ32(setclientid->se_callback_netid_len);

        READ_BUF(setclientid->se_callback_netid_len + 4);
        SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len);
        READ32(setclientid->se_callback_addr_len);

        READ_BUF(setclientid->se_callback_addr_len + 4);
        SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len);
        READ32(setclientid->se_callback_ident);

        DECODE_TAIL;
}

static int
nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
{
        DECODE_HEAD;

        READ_BUF(8 + sizeof(nfs4_verifier));
        COPYMEM(&scd_c->sc_clientid, 8);
        COPYMEM(&scd_c->sc_confirm, sizeof(nfs4_verifier));

        DECODE_TAIL;
}

/* Also used for NVERIFY */
static int
nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
{
#if 0
        struct nfsd4_compoundargs save = {
                .p = argp->p,
                .end = argp->end,
                .rqstp = argp->rqstp,
        };
        u32             ve_bmval[2];
        struct iattr    ve_iattr;           /* request */
        struct nfs4_acl *ve_acl;            /* request */
#endif
        DECODE_HEAD;

        if ((status = nfsd4_decode_bitmap(argp, verify->ve_bmval)))
                goto out;

        /* For convenience's sake, we compare raw xdr'd attributes in
         * nfsd4_proc_verify; however we still decode here just to return
         * correct error in case of bad xdr. */
#if 0
        status = nfsd4_decode_fattr(ve_bmval, &ve_iattr, &ve_acl);
        if (status == nfserr_inval) {
                status = nfserrno(status);
                goto out;
        }
#endif
        READ_BUF(4);
        READ32(verify->ve_attrlen);
        READ_BUF(verify->ve_attrlen);
        SAVEMEM(verify->ve_attrval, verify->ve_attrlen);

        DECODE_TAIL;
}

static int
nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
{
        int avail;
        int v;
        int len;
        DECODE_HEAD;

        READ_BUF(sizeof(stateid_opaque_t) + 20);
        READ32(write->wr_stateid.si_generation);
        COPYMEM(&write->wr_stateid.si_opaque, sizeof(stateid_opaque_t));
        READ64(write->wr_offset);
        READ32(write->wr_stable_how);
        if (write->wr_stable_how > 2)
                goto xdr_error;
        READ32(write->wr_buflen);

        /* Sorry .. no magic macros for this.. *
         * READ_BUF(write->wr_buflen);
         * SAVEMEM(write->wr_buf, write->wr_buflen);
         */
        avail = (char*)argp->end - (char*)argp->p;
        if (avail + argp->pagelen < write->wr_buflen) {
                printk(KERN_NOTICE "xdr error! (%s:%d)\n", __FILE__, __LINE__); 
                goto xdr_error;
        }
        write->wr_vec[0].iov_base = p;
        write->wr_vec[0].iov_len = avail;
        v = 0;
        len = write->wr_buflen;
        while (len > write->wr_vec[v].iov_len) {
                len -= write->wr_vec[v].iov_len;
                v++;
                write->wr_vec[v].iov_base = page_address(argp->pagelist[0]);
                argp->pagelist++;
                if (argp->pagelen >= PAGE_SIZE) {
                        write->wr_vec[v].iov_len = PAGE_SIZE;
                        argp->pagelen -= PAGE_SIZE;
                } else {
                        write->wr_vec[v].iov_len = argp->pagelen;
                        argp->pagelen -= len;
                }
        }
        argp->end = (u32*) (write->wr_vec[v].iov_base + write->wr_vec[v].iov_len);
        argp->p = (u32*)  (write->wr_vec[v].iov_base + (XDR_QUADLEN(len) << 2));
        write->wr_vec[v].iov_len = len;
        write->wr_vlen = v+1;

        DECODE_TAIL;
}

static int
nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
{
        DECODE_HEAD;

        READ_BUF(12);
        COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
        READ32(rlockowner->rl_owner.len);
        READ_BUF(rlockowner->rl_owner.len);
        READMEM(rlockowner->rl_owner.data, rlockowner->rl_owner.len);

        DECODE_TAIL;
}

static int
nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
{
        DECODE_HEAD;
        struct nfsd4_op *op;
        int i;

        /*
         * XXX: According to spec, we should check the tag
         * for UTF-8 compliance.  I'm postponing this for
         * now because it seems that some clients do use
         * binary tags.
         */
        READ_BUF(4);
        READ32(argp->taglen);
        READ_BUF(argp->taglen + 8);
        SAVEMEM(argp->tag, argp->taglen);
        READ32(argp->minorversion);
        READ32(argp->opcnt);

        if (argp->taglen > NFSD4_MAX_TAGLEN)
                goto xdr_error;
        if (argp->opcnt > 100)
                goto xdr_error;

        if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
                argp->ops = kmalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
                if (!argp->ops) {
                        argp->ops = argp->iops;
                        printk(KERN_INFO "nfsd: couldn't allocate room for COMPOUND\n");
                        goto xdr_error;
                }
        }

        for (i = 0; i < argp->opcnt; i++) {
                op = &argp->ops[i];
                op->replay = NULL;

                /*
                 * We can't use READ_BUF() here because we need to handle
                 * a missing opcode as an OP_WRITE + 1. So we need to check
                 * to see if we're truly at the end of our buffer or if there
                 * is another page we need to flip to.
                 */

                if (argp->p == argp->end) {
                        if (argp->pagelen < 4) {
                                /* There isn't an opcode still on the wire */
                                op->opnum = OP_WRITE + 1;
                                op->status = nfserr_bad_xdr;
                                argp->opcnt = i+1;
                                break;
                        }

                        /*
                         * False alarm. We just hit a page boundary, but there
                         * is still data available.  Move pointer across page
                         * boundary.  *snip from READ_BUF*
                         */
                        argp->p = page_address(argp->pagelist[0]);
                        argp->pagelist++;
                        if (argp->pagelen < PAGE_SIZE) {
                                argp->end = p + (argp->pagelen>>2);
                                argp->pagelen = 0;
                        } else {
                                argp->end = p + (PAGE_SIZE>>2);
                                argp->pagelen -= PAGE_SIZE;
                        }
                }
                op->opnum = ntohl(*argp->p++);

                switch (op->opnum) {
                case 2: /* Reserved operation */
                        op->opnum = OP_ILLEGAL;
                        if (argp->minorversion == 0)
                                op->status = nfserr_op_illegal;
                        else
                                op->status = nfserr_minor_vers_mismatch;
                        break;
                case OP_ACCESS:
                        op->status = nfsd4_decode_access(argp, &op->u.access);
                        break;
                case OP_CLOSE:
                        op->status = nfsd4_decode_close(argp, &op->u.close);
                        break;
                case OP_COMMIT:
                        op->status = nfsd4_decode_commit(argp, &op->u.commit);
                        break;
                case OP_CREATE:
                        op->status = nfsd4_decode_create(argp, &op->u.create);
                        break;
                case OP_DELEGRETURN:
                        op->status = nfsd4_decode_delegreturn(argp, &op->u.delegreturn);
                        break;
                case OP_GETATTR:
                        op->status = nfsd4_decode_getattr(argp, &op->u.getattr);
                        break;
                case OP_GETFH:
                        op->status = nfs_ok;
                        break;
                case OP_LINK:
                        op->status = nfsd4_decode_link(argp, &op->u.link);
                        break;
                case OP_LOCK:
                        op->status = nfsd4_decode_lock(argp, &op->u.lock);
                        break;
                case OP_LOCKT:
                        op->status = nfsd4_decode_lockt(argp, &op->u.lockt);
                        break;
                case OP_LOCKU:
                        op->status = nfsd4_decode_locku(argp, &op->u.locku);
                        break;
                case OP_LOOKUP:
                        op->status = nfsd4_decode_lookup(argp, &op->u.lookup);
                        break;
                case OP_LOOKUPP:
                        op->status = nfs_ok;
                        break;
                case OP_NVERIFY:
                        op->status = nfsd4_decode_verify(argp, &op->u.nverify);
                        break;
                case OP_OPEN:
                        op->status = nfsd4_decode_open(argp, &op->u.open);
                        break;
                case OP_OPEN_CONFIRM:
                        op->status = nfsd4_decode_open_confirm(argp, &op->u.open_confirm);
                        break;
                case OP_OPEN_DOWNGRADE:
                        op->status = nfsd4_decode_open_downgrade(argp, &op->u.open_downgrade);
                        break;
                case OP_PUTFH:
                        op->status = nfsd4_decode_putfh(argp, &op->u.putfh);
                        break;
                case OP_PUTROOTFH:
                        op->status = nfs_ok;
                        break;
                case OP_READ:
                        op->status = nfsd4_decode_read(argp, &op->u.read);
                        break;
                case OP_READDIR:
                        op->status = nfsd4_decode_readdir(argp, &op->u.readdir);
                        break;
                case OP_READLINK:
                        op->status = nfs_ok;
                        break;
                case OP_REMOVE:
                        op->status = nfsd4_decode_remove(argp, &op->u.remove);
                        break;
                case OP_RENAME:
                        op->status = nfsd4_decode_rename(argp, &op->u.rename);
                        break;
                case OP_RESTOREFH:
                        op->status = nfs_ok;
                        break;
                case OP_RENEW:
                        op->status = nfsd4_decode_renew(argp, &op->u.renew);
                        break;
                case OP_SAVEFH:
                        op->status = nfs_ok;
                        break;
                case OP_SETATTR:
                        op->status = nfsd4_decode_setattr(argp, &op->u.setattr);
                        break;
                case OP_SETCLIENTID:
                        op->status = nfsd4_decode_setclientid(argp, &op->u.setclientid);
                        break;
                case OP_SETCLIENTID_CONFIRM:
                        op->status = nfsd4_decode_setclientid_confirm(argp, &op->u.setclientid_confirm);
                        break;
                case OP_VERIFY:
                        op->status = nfsd4_decode_verify(argp, &op->u.verify);
                        break;
                case OP_WRITE:
                        op->status = nfsd4_decode_write(argp, &op->u.write);
                        break;
                case OP_RELEASE_LOCKOWNER:
                        op->status = nfsd4_decode_release_lockowner(argp, &op->u.release_lockowner);
                        break;
                default:
                        op->opnum = OP_ILLEGAL;
                        op->status = nfserr_op_illegal;
                        break;
                }

                if (op->status) {
                        argp->opcnt = i+1;
                        break;
                }
        }

        DECODE_TAIL;
}
/*
 * END OF "GENERIC" DECODE ROUTINES.
 */

/*
 * START OF "GENERIC" ENCODE ROUTINES.
 *   These may look a little ugly since they are imported from a "generic"
 * set of XDR encode/decode routines which are intended to be shared by
 * all of our NFSv4 implementations (OpenBSD, MacOS X...).
 *
 * If the pain of reading these is too great, it should be a straightforward
 * task to translate them into Linux-specific versions which are more
 * consistent with the style used in NFSv2/v3...
 */
#define ENCODE_HEAD              u32 *p

#define WRITE32(n)               *p++ = htonl(n)
#define WRITE64(n)               do {                           \
        *p++ = htonl((u32)((n) >> 32));                         \
        *p++ = htonl((u32)(n));                                 \
} while (0)
#define WRITEMEM(ptr,nbytes)     do {                           \
        *(p + XDR_QUADLEN(nbytes) -1) = 0;                      \
        memcpy(p, ptr, nbytes);                                 \
        p += XDR_QUADLEN(nbytes);                               \
} while (0)
#define WRITECINFO(c)           do {                            \
        *p++ = htonl(c.atomic);                                 \
        *p++ = htonl(c.before_ctime_sec);                               \
        *p++ = htonl(c.before_ctime_nsec);                              \
        *p++ = htonl(c.after_ctime_sec);                                \
        *p++ = htonl(c.after_ctime_nsec);                               \
} while (0)

#define RESERVE_SPACE(nbytes)   do {                            \
        p = resp->p;                                            \
        BUG_ON(p + XDR_QUADLEN(nbytes) > resp->end);            \
} while (0)
#define ADJUST_ARGS()           resp->p = p

/*
 * Header routine to setup seqid operation replay cache
 */
#define ENCODE_SEQID_OP_HEAD                                    \
        u32 *p;                                                 \
        u32 *save;                                              \
                                                                \
        save = resp->p;

/*
 * Routine for encoding the result of a "seqid-mutating" NFSv4 operation.  This
 * is where sequence id's are incremented, and the replay cache is filled.
 * Note that we increment sequence id's here, at the last moment, so we're sure
 * we know whether the error to be returned is a sequence id mutating error.
 */

#define ENCODE_SEQID_OP_TAIL(stateowner) do {                   \
        if (seqid_mutating_err(nfserr) && stateowner) {         \
                stateowner->so_seqid++;                         \
                stateowner->so_replay.rp_status = nfserr;       \
                stateowner->so_replay.rp_buflen =               \
                          (((char *)(resp)->p - (char *)save)); \
                memcpy(stateowner->so_replay.rp_buf, save,      \
                        stateowner->so_replay.rp_buflen);       \
        } } while (0);


static u32 nfs4_ftypes[16] = {
        NF4BAD,  NF4FIFO, NF4CHR, NF4BAD,
        NF4DIR,  NF4BAD,  NF4BLK, NF4BAD,
        NF4REG,  NF4BAD,  NF4LNK, NF4BAD,
        NF4SOCK, NF4BAD,  NF4LNK, NF4BAD,
};

static int
nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
                        u32 **p, int *buflen)
{
        int status;

        if (*buflen < (XDR_QUADLEN(IDMAP_NAMESZ) << 2) + 4)
                return nfserr_resource;
        if (whotype != NFS4_ACL_WHO_NAMED)
                status = nfs4_acl_write_who(whotype, (u8 *)(*p + 1));
        else if (group)
                status = nfsd_map_gid_to_name(rqstp, id, (u8 *)(*p + 1));
        else
                status = nfsd_map_uid_to_name(rqstp, id, (u8 *)(*p + 1));
        if (status < 0)
                return nfserrno(status);
        *p = xdr_encode_opaque(*p, NULL, status);
        *buflen -= (XDR_QUADLEN(status) << 2) + 4;
        BUG_ON(*buflen < 0);
        return 0;
}

static inline int
nfsd4_encode_user(struct svc_rqst *rqstp, uid_t uid, u32 **p, int *buflen)
{
        return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, uid, 0, p, buflen);
}

static inline int
nfsd4_encode_group(struct svc_rqst *rqstp, uid_t gid, u32 **p, int *buflen)
{
        return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, gid, 1, p, buflen);
}

static inline int
nfsd4_encode_aclname(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
                u32 **p, int *buflen)
{
        return nfsd4_encode_name(rqstp, whotype, id, group, p, buflen);
}


/*
 * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
 * ourselves.
 *
 * @countp is the buffer size in _words_; upon successful return this becomes
 * replaced with the number of words written.
 */
int
nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
                struct dentry *dentry, u32 *buffer, int *countp, u32 *bmval,
                struct svc_rqst *rqstp)
{
        u32 bmval0 = bmval[0];
        u32 bmval1 = bmval[1];
        struct kstat stat;
        struct svc_fh tempfh;
        struct kstatfs statfs;
        int buflen = *countp << 2;
        u32 *attrlenp;
        u32 dummy;
        u64 dummy64;
        u32 *p = buffer;
        int status;
        int aclsupport = 0;
        struct nfs4_acl *acl = NULL;

        BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
        BUG_ON(bmval0 & ~NFSD_SUPPORTED_ATTRS_WORD0);
        BUG_ON(bmval1 & ~NFSD_SUPPORTED_ATTRS_WORD1);

        status = vfs_getattr(exp->ex_mnt, dentry, &stat);
        if (status)
                goto out_nfserr;
        if ((bmval0 & (FATTR4_WORD0_FILES_FREE | FATTR4_WORD0_FILES_TOTAL)) ||
            (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
                       FATTR4_WORD1_SPACE_TOTAL))) {
                status = vfs_statfs(dentry, &statfs);
                if (status)
                        goto out_nfserr;
        }
        if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
                fh_init(&tempfh, NFS4_FHSIZE);
                status = fh_compose(&tempfh, exp, dentry, NULL);
                if (status)
                        goto out;
                fhp = &tempfh;
        }
        if (bmval0 & (FATTR4_WORD0_ACL | FATTR4_WORD0_ACLSUPPORT
                        | FATTR4_WORD0_SUPPORTED_ATTRS)) {
                status = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
                aclsupport = (status == 0);
                if (bmval0 & FATTR4_WORD0_ACL) {
                        if (status == -EOPNOTSUPP)
                                bmval0 &= ~FATTR4_WORD0_ACL;
                        else if (status == -EINVAL) {
                                status = nfserr_attrnotsupp;
                                goto out;
                        } else if (status != 0)
                                goto out_nfserr;
                }
        }
        if ((buflen -= 16) < 0)
                goto out_resource;

        WRITE32(2);
        WRITE32(bmval0);
        WRITE32(bmval1);
        attrlenp = p++;                /* to be backfilled later */

        if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
                if ((buflen -= 12) < 0)
                        goto out_resource;
                WRITE32(2);
                WRITE32(aclsupport ?
                        NFSD_SUPPORTED_ATTRS_WORD0 :
                        NFSD_SUPPORTED_ATTRS_WORD0 & ~FATTR4_WORD0_ACL);
                WRITE32(NFSD_SUPPORTED_ATTRS_WORD1);
        }
        if (bmval0 & FATTR4_WORD0_TYPE) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                dummy = nfs4_ftypes[(stat.mode & S_IFMT) >> 12];
                if (dummy == NF4BAD)
                        goto out_serverfault;
                WRITE32(dummy);
        }
        if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
                        WRITE32(NFS4_FH_PERSISTENT);
                else
                        WRITE32(NFS4_FH_PERSISTENT|NFS4_FH_VOL_RENAME);
        }
        if (bmval0 & FATTR4_WORD0_CHANGE) {
                /*
                 * Note: This _must_ be consistent with the scheme for writing
                 * change_info, so any changes made here must be reflected there
                 * as well.  (See xdr4.h:set_change_info() and the WRITECINFO()
                 * macro above.)
                 */
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE32(stat.ctime.tv_sec);
                WRITE32(stat.ctime.tv_nsec);
        }
        if (bmval0 & FATTR4_WORD0_SIZE) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64(stat.size);
        }
        if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(0);
        }
        if (bmval0 & FATTR4_WORD0_FSID) {
                if ((buflen -= 16) < 0)
                        goto out_resource;
                if (is_fsid(fhp, rqstp->rq_reffh)) {
                        WRITE64((u64)exp->ex_fsid);
                        WRITE64((u64)0);
                } else {
                        WRITE32(0);
                        WRITE32(MAJOR(stat.dev));
                        WRITE32(0);
                        WRITE32(MINOR(stat.dev));
                }
        }
        if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(0);
        }
        if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(NFSD_LEASE_TIME);
        }
        if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(0);
        }
        if (bmval0 & FATTR4_WORD0_ACL) {
                struct nfs4_ace *ace;
                struct list_head *h;

                if (acl == NULL) {
                        if ((buflen -= 4) < 0)
                                goto out_resource;

                        WRITE32(0);
                        goto out_acl;
                }
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(acl->naces);

                list_for_each(h, &acl->ace_head) {
                        ace = list_entry(h, struct nfs4_ace, l_ace);

                        if ((buflen -= 4*3) < 0)
                                goto out_resource;
                        WRITE32(ace->type);
                        WRITE32(ace->flag);
                        WRITE32(ace->access_mask & NFS4_ACE_MASK_ALL);
                        status = nfsd4_encode_aclname(rqstp, ace->whotype,
                                ace->who, ace->flag & NFS4_ACE_IDENTIFIER_GROUP,
                                &p, &buflen);
                        if (status == nfserr_resource)
                                goto out_resource;
                        if (status)
                                goto out;
                }
        }
out_acl:
        if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(aclsupport ?
                        ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
        }
        if (bmval0 & FATTR4_WORD0_CANSETTIME) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
                buflen -= (XDR_QUADLEN(fhp->fh_handle.fh_size) << 2) + 4;
                if (buflen < 0)
                        goto out_resource;
                WRITE32(fhp->fh_handle.fh_size);
                WRITEMEM(&fhp->fh_handle.fh_base, fhp->fh_handle.fh_size);
        }
        if (bmval0 & FATTR4_WORD0_FILEID) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) stat.ino);
        }
        if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) statfs.f_ffree);
        }
        if (bmval0 & FATTR4_WORD0_FILES_FREE) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) statfs.f_ffree);
        }
        if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) statfs.f_files);
        }
        if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64(~(u64)0);
        }
        if (bmval0 & FATTR4_WORD0_MAXLINK) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(255);
        }
        if (bmval0 & FATTR4_WORD0_MAXNAME) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(~(u32) 0);
        }
        if (bmval0 & FATTR4_WORD0_MAXREAD) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) NFSSVC_MAXBLKSIZE);
        }
        if (bmval0 & FATTR4_WORD0_MAXWRITE) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE64((u64) NFSSVC_MAXBLKSIZE);
        }
        if (bmval1 & FATTR4_WORD1_MODE) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(stat.mode & S_IALLUGO);
        }
        if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(1);
        }
        if (bmval1 & FATTR4_WORD1_NUMLINKS) {
                if ((buflen -= 4) < 0)
                        goto out_resource;
                WRITE32(stat.nlink);
        }
        if (bmval1 & FATTR4_WORD1_OWNER) {
                status = nfsd4_encode_user(rqstp, stat.uid, &p, &buflen);
                if (status == nfserr_resource)
                        goto out_resource;
                if (status)
                        goto out;
        }
        if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
                status = nfsd4_encode_group(rqstp, stat.gid, &p, &buflen);
                if (status == nfserr_resource)
                        goto out_resource;
                if (status)
                        goto out;
        }
        if (bmval1 & FATTR4_WORD1_RAWDEV) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                WRITE32((u32) MAJOR(stat.rdev));
                WRITE32((u32) MINOR(stat.rdev));
        }
        if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
                WRITE64(dummy64);
        }
        if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
                WRITE64(dummy64);
        }
        if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
                WRITE64(dummy64);
        }
        if (bmval1 & FATTR4_WORD1_SPACE_USED) {
                if ((buflen -= 8) < 0)
                        goto out_resource;
                dummy64 = (u64)stat.blocks << 9;
                WRITE64(dummy64);
        }
        if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
                if ((buflen -= 12) < 0)
                        goto out_resource;
                WRITE32(0);
                WRITE32(stat.atime.tv_sec);
                WRITE32(stat.atime.tv_nsec);
        }
        if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
                if ((buflen -= 12) < 0)
                        goto out_resource;
                WRITE32(0);
                WRITE32(1);
                WRITE32(0);
        }
        if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
                if ((buflen -= 12) < 0)
                        goto out_resource;
                WRITE32(0);
                WRITE32(stat.ctime.tv_sec);
                WRITE32(stat.ctime.tv_nsec);
        }
        if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
                if ((buflen -= 12) < 0)
                        goto out_resource;
                WRITE32(0);
                WRITE32(stat.mtime.tv_sec);
                WRITE32(stat.mtime.tv_nsec);
        }
        if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
                struct dentry *mnt_pnt, *mnt_root;

                if ((buflen -= 8) < 0)
                        goto out_resource;
                mnt_root = exp->ex_mnt->mnt_root;
                if (mnt_root->d_inode == dentry->d_inode) {
                        mnt_pnt = exp->ex_mnt->mnt_mountpoint;
                        WRITE64((u64) mnt_pnt->d_inode->i_ino);
                } else
                        WRITE64((u64) stat.ino);
        }
        *attrlenp = htonl((char *)p - (char *)attrlenp - 4);
        *countp = p - buffer;
        status = nfs_ok;

out:
        nfs4_acl_free(acl);
        if (fhp == &tempfh)
                fh_put(&tempfh);
        return status;
out_nfserr:
        status = nfserrno(status);
        goto out;
out_resource:
        *countp = 0;
        status = nfserr_resource;
        goto out;
out_serverfault:
        status = nfserr_serverfault;
        goto out;
}

static int
nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
                const char *name, int namlen, u32 *p, int *buflen)
{
        struct svc_export *exp = cd->rd_fhp->fh_export;
        struct dentry *dentry;
        int nfserr;

        dentry = lookup_one_len(name, cd->rd_fhp->fh_dentry, namlen);
        if (IS_ERR(dentry))
                return nfserrno(PTR_ERR(dentry));

        exp_get(exp);
        if (d_mountpoint(dentry)) {
                if (nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp)) {
                /*
                 * -EAGAIN is the only error returned from
                 * nfsd_cross_mnt() and it indicates that an
                 * up-call has  been initiated to fill in the export
                 * options on exp.  When the answer comes back,
                 * this call will be retried.
                 */
                        nfserr = nfserr_dropit;
                        goto out_put;
                }

        }
        nfserr = nfsd4_encode_fattr(NULL, exp, dentry, p, buflen, cd->rd_bmval,
                                        cd->rd_rqstp);
out_put:
        dput(dentry);
        exp_put(exp);
        return nfserr;
}

static u32 *
nfsd4_encode_rdattr_error(u32 *p, int buflen, int nfserr)
{
        u32 *attrlenp;

        if (buflen < 6)
                return NULL;
        *p++ = htonl(2);
        *p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
        *p++ = htonl(0);                         /* bmval1 */

        attrlenp = p++;
        *p++ = nfserr;       /* no htonl */
        *attrlenp = htonl((char *)p - (char *)attrlenp - 4);
        return p;
}

static int
nfsd4_encode_dirent(struct readdir_cd *ccd, const char *name, int namlen,
                    loff_t offset, ino_t ino, unsigned int d_type)
{
        struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
        int buflen;
        u32 *p = cd->buffer;
        int nfserr = nfserr_toosmall;

        /* In nfsv4, "." and ".." never make it onto the wire.. */
        if (name && isdotent(name, namlen)) {
                cd->common.err = nfs_ok;
                return 0;
        }

        if (cd->offset)
                xdr_encode_hyper(cd->offset, (u64) offset);

        buflen = cd->buflen - 4 - XDR_QUADLEN(namlen);
        if (buflen < 0)
                goto fail;

        *p++ = xdr_one;                             /* mark entry present */
        cd->offset = p;                             /* remember pointer */
        p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
        p = xdr_encode_array(p, name, namlen);      /* name length & name */

        nfserr = nfsd4_encode_dirent_fattr(cd, name, namlen, p, &buflen);
        switch (nfserr) {
        case nfs_ok:
                p += buflen;
                break;
        case nfserr_resource:
                nfserr = nfserr_toosmall;
                goto fail;
        case nfserr_dropit:
                goto fail;
        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(p, buflen, nfserr);
                if (p == NULL) {
                        nfserr = nfserr_toosmall;
                        goto fail;
                }
        }
        cd->buflen -= (p - cd->buffer);
        cd->buffer = p;
        cd->common.err = nfs_ok;
        return 0;
fail:
        cd->common.err = nfserr;
        return -EINVAL;
}

static void
nfsd4_encode_access(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_access *access)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(8);
                WRITE32(access->ac_supported);
                WRITE32(access->ac_resp_access);
                ADJUST_ARGS();
        }
}

static void
nfsd4_encode_close(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_close *close)
{
        ENCODE_SEQID_OP_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(sizeof(stateid_t));
                WRITE32(close->cl_stateid.si_generation);
                WRITEMEM(&close->cl_stateid.si_opaque, sizeof(stateid_opaque_t));
                ADJUST_ARGS();
        }
        ENCODE_SEQID_OP_TAIL(close->cl_stateowner);
}


static void
nfsd4_encode_commit(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_commit *commit)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(8);
                WRITEMEM(commit->co_verf.data, 8);
                ADJUST_ARGS();
        }
}

static void
nfsd4_encode_create(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_create *create)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(32);
                WRITECINFO(create->cr_cinfo);
                WRITE32(2);
                WRITE32(create->cr_bmval[0]);
                WRITE32(create->cr_bmval[1]);
                ADJUST_ARGS();
        }
}

static int
nfsd4_encode_getattr(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_getattr *getattr)
{
        struct svc_fh *fhp = getattr->ga_fhp;
        int buflen;

        if (nfserr)
                return nfserr;

        buflen = resp->end - resp->p - (COMPOUND_ERR_SLACK_SPACE >> 2);
        nfserr = nfsd4_encode_fattr(fhp, fhp->fh_export, fhp->fh_dentry,
                                    resp->p, &buflen, getattr->ga_bmval,
                                    resp->rqstp);

        if (!nfserr)
                resp->p += buflen;
        return nfserr;
}

static void
nfsd4_encode_getfh(struct nfsd4_compoundres *resp, int nfserr, struct svc_fh *fhp)
{
        unsigned int len;
        ENCODE_HEAD;

        if (!nfserr) {
                len = fhp->fh_handle.fh_size;
                RESERVE_SPACE(len + 4);
                WRITE32(len);
                WRITEMEM(&fhp->fh_handle.fh_base, len);
                ADJUST_ARGS();
        }
}

/*
* Including all fields other than the name, a LOCK4denied structure requires
*   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
*/
static void
nfsd4_encode_lock_denied(struct nfsd4_compoundres *resp, struct nfsd4_lock_denied *ld)
{
        ENCODE_HEAD;

        RESERVE_SPACE(32 + XDR_LEN(ld->ld_sop ? ld->ld_sop->so_owner.len : 0));
        WRITE64(ld->ld_start);
        WRITE64(ld->ld_length);
        WRITE32(ld->ld_type);
        if (ld->ld_sop) {
                WRITEMEM(&ld->ld_clientid, 8);
                WRITE32(ld->ld_sop->so_owner.len);
                WRITEMEM(ld->ld_sop->so_owner.data, ld->ld_sop->so_owner.len);
                kref_put(&ld->ld_sop->so_ref, nfs4_free_stateowner);
        }  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
                WRITE64((u64)0); /* clientid */
                WRITE32(0); /* length of owner name */
        }
        ADJUST_ARGS();
}

static void
nfsd4_encode_lock(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_lock *lock)
{
        ENCODE_SEQID_OP_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(4 + sizeof(stateid_t));
                WRITE32(lock->lk_resp_stateid.si_generation);
                WRITEMEM(&lock->lk_resp_stateid.si_opaque, sizeof(stateid_opaque_t));
                ADJUST_ARGS();
        } else if (nfserr == nfserr_denied)
                nfsd4_encode_lock_denied(resp, &lock->lk_denied);

        ENCODE_SEQID_OP_TAIL(lock->lk_replay_owner);
}

static void
nfsd4_encode_lockt(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_lockt *lockt)
{
        if (nfserr == nfserr_denied)
                nfsd4_encode_lock_denied(resp, &lockt->lt_denied);
}

static void
nfsd4_encode_locku(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_locku *locku)
{
        ENCODE_SEQID_OP_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(sizeof(stateid_t));
                WRITE32(locku->lu_stateid.si_generation);
                WRITEMEM(&locku->lu_stateid.si_opaque, sizeof(stateid_opaque_t));
                ADJUST_ARGS();
        }
                                        
        ENCODE_SEQID_OP_TAIL(locku->lu_stateowner);
}


static void
nfsd4_encode_link(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_link *link)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(20);
                WRITECINFO(link->li_cinfo);
                ADJUST_ARGS();
        }
}


static void
nfsd4_encode_open(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_open *open)
{
        ENCODE_SEQID_OP_HEAD;

        if (nfserr)
                goto out;

        RESERVE_SPACE(36 + sizeof(stateid_t));
        WRITE32(open->op_stateid.si_generation);
        WRITEMEM(&open->op_stateid.si_opaque, sizeof(stateid_opaque_t));
        WRITECINFO(open->op_cinfo);
        WRITE32(open->op_rflags);
        WRITE32(2);
        WRITE32(open->op_bmval[0]);
        WRITE32(open->op_bmval[1]);
        WRITE32(open->op_delegate_type);
        ADJUST_ARGS();

        switch (open->op_delegate_type) {
        case NFS4_OPEN_DELEGATE_NONE:
                break;
        case NFS4_OPEN_DELEGATE_READ:
                RESERVE_SPACE(20 + sizeof(stateid_t));
                WRITEMEM(&open->op_delegate_stateid, sizeof(stateid_t));
                WRITE32(open->op_recall);

                /*
                 * TODO: ACE's in delegations
                 */
                WRITE32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
                WRITE32(0);
                WRITE32(0);
                WRITE32(0);   /* XXX: is NULL principal ok? */
                ADJUST_ARGS();
                break;
        case NFS4_OPEN_DELEGATE_WRITE:
                RESERVE_SPACE(32 + sizeof(stateid_t));
                WRITEMEM(&open->op_delegate_stateid, sizeof(stateid_t));
                WRITE32(0);

                /*
                 * TODO: space_limit's in delegations
                 */
                WRITE32(NFS4_LIMIT_SIZE);
                WRITE32(~(u32)0);
                WRITE32(~(u32)0);

                /*
                 * TODO: ACE's in delegations
                 */
                WRITE32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
                WRITE32(0);
                WRITE32(0);
                WRITE32(0);   /* XXX: is NULL principal ok? */
                ADJUST_ARGS();
                break;
        default:
                BUG();
        }
        /* XXX save filehandle here */
out:
        ENCODE_SEQID_OP_TAIL(open->op_stateowner);
}

static void
nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_open_confirm *oc)
{
        ENCODE_SEQID_OP_HEAD;
                                        
        if (!nfserr) {
                RESERVE_SPACE(sizeof(stateid_t));
                WRITE32(oc->oc_resp_stateid.si_generation);
                WRITEMEM(&oc->oc_resp_stateid.si_opaque, sizeof(stateid_opaque_t));
                ADJUST_ARGS();
        }

        ENCODE_SEQID_OP_TAIL(oc->oc_stateowner);
}

static void
nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_open_downgrade *od)
{
        ENCODE_SEQID_OP_HEAD;
                                        
        if (!nfserr) {
                RESERVE_SPACE(sizeof(stateid_t));
                WRITE32(od->od_stateid.si_generation);
                WRITEMEM(&od->od_stateid.si_opaque, sizeof(stateid_opaque_t));
                ADJUST_ARGS();
        }

        ENCODE_SEQID_OP_TAIL(od->od_stateowner);
}

static int
nfsd4_encode_read(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_read *read)
{
        u32 eof;
        int v, pn;
        unsigned long maxcount; 
        long len;
        ENCODE_HEAD;

        if (nfserr)
                return nfserr;
        if (resp->xbuf->page_len)
                return nfserr_resource;

        RESERVE_SPACE(8); /* eof flag and byte count */

        maxcount = NFSSVC_MAXBLKSIZE;
        if (maxcount > read->rd_length)
                maxcount = read->rd_length;

        len = maxcount;
        v = 0;
        while (len > 0) {
                pn = resp->rqstp->rq_resused;
                svc_take_page(resp->rqstp);
                read->rd_iov[v].iov_base = page_address(resp->rqstp->rq_respages[pn]);
                read->rd_iov[v].iov_len = len < PAGE_SIZE ? len : PAGE_SIZE;
                v++;
                len -= PAGE_SIZE;
        }
        read->rd_vlen = v;

        nfserr = nfsd_read(read->rd_rqstp, read->rd_fhp, read->rd_filp,
                        read->rd_offset, read->rd_iov, read->rd_vlen,
                        &maxcount);

        if (nfserr == nfserr_symlink)
                nfserr = nfserr_inval;
        if (nfserr)
                return nfserr;
        eof = (read->rd_offset + maxcount >= read->rd_fhp->fh_dentry->d_inode->i_size);

        WRITE32(eof);
        WRITE32(maxcount);
        ADJUST_ARGS();
        resp->xbuf->head[0].iov_len = (char*)p
                                        - (char*)resp->xbuf->head[0].iov_base;
        resp->xbuf->page_len = maxcount;

        /* Use rest of head for padding and remaining ops: */
        resp->rqstp->rq_restailpage = 0;
        resp->xbuf->tail[0].iov_base = p;
        resp->xbuf->tail[0].iov_len = 0;
        if (maxcount&3) {
                RESERVE_SPACE(4);
                WRITE32(0);
                resp->xbuf->tail[0].iov_base += maxcount&3;
                resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
                ADJUST_ARGS();
        }
        return 0;
}

static int
nfsd4_encode_readlink(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_readlink *readlink)
{
        int maxcount;
        char *page;
        ENCODE_HEAD;

        if (nfserr)
                return nfserr;
        if (resp->xbuf->page_len)
                return nfserr_resource;

        svc_take_page(resp->rqstp);
        page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);

        maxcount = PAGE_SIZE;
        RESERVE_SPACE(4);

        /*
         * XXX: By default, the ->readlink() VFS op will truncate symlinks
         * if they would overflow the buffer.  Is this kosher in NFSv4?  If
         * not, one easy fix is: if ->readlink() precisely fills the buffer,
         * assume that truncation occurred, and return NFS4ERR_RESOURCE.
         */
        nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, page, &maxcount);
        if (nfserr == nfserr_isdir)
                return nfserr_inval;
        if (nfserr)
                return nfserr;

        WRITE32(maxcount);
        ADJUST_ARGS();
        resp->xbuf->head[0].iov_len = (char*)p
                                - (char*)resp->xbuf->head[0].iov_base;
        resp->xbuf->page_len = maxcount;

        /* Use rest of head for padding and remaining ops: */
        resp->rqstp->rq_restailpage = 0;
        resp->xbuf->tail[0].iov_base = p;
        resp->xbuf->tail[0].iov_len = 0;
        if (maxcount&3) {
                RESERVE_SPACE(4);
                WRITE32(0);
                resp->xbuf->tail[0].iov_base += maxcount&3;
                resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
                ADJUST_ARGS();
        }
        return 0;
}

static int
nfsd4_encode_readdir(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_readdir *readdir)
{
        int maxcount;
        loff_t offset;
        u32 *page, *savep, *tailbase;
        ENCODE_HEAD;

        if (nfserr)
                return nfserr;
        if (resp->xbuf->page_len)
                return nfserr_resource;

        RESERVE_SPACE(8);  /* verifier */
        savep = p;

        /* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
        WRITE32(0);
        WRITE32(0);
        ADJUST_ARGS();
        resp->xbuf->head[0].iov_len = ((char*)resp->p) - (char*)resp->xbuf->head[0].iov_base;
        tailbase = p;

        maxcount = PAGE_SIZE;
        if (maxcount > readdir->rd_maxcount)
                maxcount = readdir->rd_maxcount;

        /*
         * Convert from bytes to words, account for the two words already
         * written, make sure to leave two words at the end for the next
         * pointer and eof field.
         */
        maxcount = (maxcount >> 2) - 4;
        if (maxcount < 0) {
                nfserr =  nfserr_toosmall;
                goto err_no_verf;
        }

        svc_take_page(resp->rqstp);
        page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);
        readdir->common.err = 0;
        readdir->buflen = maxcount;
        readdir->buffer = page;
        readdir->offset = NULL;

        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 &&
            readdir->buffer == page) 
                nfserr = nfserr_toosmall;
        if (nfserr == nfserr_symlink)
                nfserr = nfserr_notdir;
        if (nfserr)
                goto err_no_verf;

        if (readdir->offset)
                xdr_encode_hyper(readdir->offset, offset);

        p = readdir->buffer;
        *p++ = 0;       /* no more entries */
        *p++ = htonl(readdir->common.err == nfserr_eof);
        resp->xbuf->page_len = ((char*)p) - (char*)page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);

        /* Use rest of head for padding and remaining ops: */
        resp->rqstp->rq_restailpage = 0;
        resp->xbuf->tail[0].iov_base = tailbase;
        resp->xbuf->tail[0].iov_len = 0;
        resp->p = resp->xbuf->tail[0].iov_base;
        resp->end = resp->p + (PAGE_SIZE - resp->xbuf->head[0].iov_len)/4;

        return 0;
err_no_verf:
        p = savep;
        ADJUST_ARGS();
        return nfserr;
}

static void
nfsd4_encode_remove(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_remove *remove)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(20);
                WRITECINFO(remove->rm_cinfo);
                ADJUST_ARGS();
        }
}

static void
nfsd4_encode_rename(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_rename *rename)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(40);
                WRITECINFO(rename->rn_sinfo);
                WRITECINFO(rename->rn_tinfo);
                ADJUST_ARGS();
        }
}

/*
 * The SETATTR encode routine is special -- it always encodes a bitmap,
 * regardless of the error status.
 */
static void
nfsd4_encode_setattr(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_setattr *setattr)
{
        ENCODE_HEAD;

        RESERVE_SPACE(12);
        if (nfserr) {
                WRITE32(2);
                WRITE32(0);
                WRITE32(0);
        }
        else {
                WRITE32(2);
                WRITE32(setattr->sa_bmval[0]);
                WRITE32(setattr->sa_bmval[1]);
        }
        ADJUST_ARGS();
}

static void
nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_setclientid *scd)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(8 + sizeof(nfs4_verifier));
                WRITEMEM(&scd->se_clientid, 8);
                WRITEMEM(&scd->se_confirm, sizeof(nfs4_verifier));
                ADJUST_ARGS();
        }
        else if (nfserr == nfserr_clid_inuse) {
                RESERVE_SPACE(8);
                WRITE32(0);
                WRITE32(0);
                ADJUST_ARGS();
        }
}

static void
nfsd4_encode_write(struct nfsd4_compoundres *resp, int nfserr, struct nfsd4_write *write)
{
        ENCODE_HEAD;

        if (!nfserr) {
                RESERVE_SPACE(16);
                WRITE32(write->wr_bytes_written);
                WRITE32(write->wr_how_written);
                WRITEMEM(write->wr_verifier.data, 8);
                ADJUST_ARGS();
        }
}

void
nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
{
        u32 *statp;
        ENCODE_HEAD;

        RESERVE_SPACE(8);
        WRITE32(op->opnum);
        statp = p++;    /* to be backfilled at the end */
        ADJUST_ARGS();

        switch (op->opnum) {
        case OP_ACCESS:
                nfsd4_encode_access(resp, op->status, &op->u.access);
                break;
        case OP_CLOSE:
                nfsd4_encode_close(resp, op->status, &op->u.close);
                break;
        case OP_COMMIT:
                nfsd4_encode_commit(resp, op->status, &op->u.commit);
                break;
        case OP_CREATE:
                nfsd4_encode_create(resp, op->status, &op->u.create);
                break;
        case OP_DELEGRETURN:
                break;
        case OP_GETATTR:
                op->status = nfsd4_encode_getattr(resp, op->status, &op->u.getattr);
                break;
        case OP_GETFH:
                nfsd4_encode_getfh(resp, op->status, op->u.getfh);
                break;
        case OP_LINK:
                nfsd4_encode_link(resp, op->status, &op->u.link);
                break;
        case OP_LOCK:
                nfsd4_encode_lock(resp, op->status, &op->u.lock);
                break;
        case OP_LOCKT:
                nfsd4_encode_lockt(resp, op->status, &op->u.lockt);
                break;
        case OP_LOCKU:
                nfsd4_encode_locku(resp, op->status, &op->u.locku);
                break;
        case OP_LOOKUP:
                break;
        case OP_LOOKUPP:
                break;
        case OP_NVERIFY:
                break;
        case OP_OPEN:
                nfsd4_encode_open(resp, op->status, &op->u.open);
                break;
        case OP_OPEN_CONFIRM:
                nfsd4_encode_open_confirm(resp, op->status, &op->u.open_confirm);
                break;
        case OP_OPEN_DOWNGRADE:
                nfsd4_encode_open_downgrade(resp, op->status, &op->u.open_downgrade);
                break;
        case OP_PUTFH:
                break;
        case OP_PUTROOTFH:
                break;
        case OP_READ:
                op->status = nfsd4_encode_read(resp, op->status, &op->u.read);
                break;
        case OP_READDIR:
                op->status = nfsd4_encode_readdir(resp, op->status, &op->u.readdir);
                break;
        case OP_READLINK:
                op->status = nfsd4_encode_readlink(resp, op->status, &op->u.readlink);
                break;
        case OP_REMOVE:
                nfsd4_encode_remove(resp, op->status, &op->u.remove);
                break;
        case OP_RENAME:
                nfsd4_encode_rename(resp, op->status, &op->u.rename);
                break;
        case OP_RENEW:
                break;
        case OP_RESTOREFH:
                break;
        case OP_SAVEFH:
                break;
        case OP_SETATTR:
                nfsd4_encode_setattr(resp, op->status, &op->u.setattr);
                break;
        case OP_SETCLIENTID:
                nfsd4_encode_setclientid(resp, op->status, &op->u.setclientid);
                break;
        case OP_SETCLIENTID_CONFIRM:
                break;
        case OP_VERIFY:
                break;
        case OP_WRITE:
                nfsd4_encode_write(resp, op->status, &op->u.write);
                break;
        case OP_RELEASE_LOCKOWNER:
                break;
        default:
                break;
        }

        /*
         * Note: We write the status directly, instead of using WRITE32(),
         * since it is already in network byte order.
         */
        *statp = 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.
 *
 * called with nfs4_lock_state() held
 */
void
nfsd4_encode_replay(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
{
        ENCODE_HEAD;
        struct nfs4_replay *rp = op->replay;

        BUG_ON(!rp);

        RESERVE_SPACE(8);
        WRITE32(op->opnum);
        *p++ = rp->rp_status;  /* already xdr'ed */
        ADJUST_ARGS();

        RESERVE_SPACE(rp->rp_buflen);
        WRITEMEM(rp->rp_buf, rp->rp_buflen);
        ADJUST_ARGS();
}

/*
 * END OF "GENERIC" ENCODE ROUTINES.
 */

int
nfs4svc_encode_voidres(struct svc_rqst *rqstp, u32 *p, void *dummy)
{
        return xdr_ressize_check(rqstp, p);
}

void nfsd4_release_compoundargs(struct nfsd4_compoundargs *args)
{
        if (args->ops != args->iops) {
                kfree(args->ops);
                args->ops = args->iops;
        }
        kfree(args->tmpp);
        args->tmpp = NULL;
        while (args->to_free) {
                struct tmpbuf *tb = args->to_free;
                args->to_free = tb->next;
                tb->release(tb->buf);
                kfree(tb);
        }
}

int
nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, u32 *p, struct nfsd4_compoundargs *args)
{
        int status;

        args->p = p;
        args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
        args->pagelist = rqstp->rq_arg.pages;
        args->pagelen = rqstp->rq_arg.page_len;
        args->tmpp = NULL;
        args->to_free = NULL;
        args->ops = args->iops;
        args->rqstp = rqstp;

        status = nfsd4_decode_compound(args);
        if (status) {
                nfsd4_release_compoundargs(args);
        }
        return !status;
}

int
nfs4svc_encode_compoundres(struct svc_rqst *rqstp, u32 *p, struct nfsd4_compoundres *resp)
{
        /*
         * All that remains is to write the tag and operation count...
         */
        struct kvec *iov;
        p = resp->tagp;
        *p++ = htonl(resp->taglen);
        memcpy(p, resp->tag, resp->taglen);
        p += XDR_QUADLEN(resp->taglen);
        *p++ = htonl(resp->opcnt);

        if (rqstp->rq_res.page_len) 
                iov = &rqstp->rq_res.tail[0];
        else
                iov = &rqstp->rq_res.head[0];
        iov->iov_len = ((char*)resp->p) - (char*)iov->iov_base;
        BUG_ON(iov->iov_len > PAGE_SIZE);
        return 1;
}

/*
 * Local variables:
 *  c-basic-offset: 8
 * End:
 */