nfs4proc.c

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/*
 *  Server-side procedures for NFSv4.
 *
 *  Copyright (c) 2002 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <[email protected]>
 *  Andy Adamson   <[email protected]>
 *
 *  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 "idmap.h"
#include "cache.h"
#include "xdr4.h"
#include "vfs.h"
#include "current_stateid.h"

#define NFSDDBG_FACILITY        NFSDDBG_PROC

static u32 nfsd_attrmask[] = {
    NFSD_WRITEABLE_ATTRS_WORD0,
    NFSD_WRITEABLE_ATTRS_WORD1,
    NFSD_WRITEABLE_ATTRS_WORD2
};

static u32 nfsd41_ex_attrmask[] = {
    NFSD_SUPPATTR_EXCLCREAT_WORD0,
    NFSD_SUPPATTR_EXCLCREAT_WORD1,
    NFSD_SUPPATTR_EXCLCREAT_WORD2
};

static __be32
check_attr_support(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           u32 *bmval, u32 *writable)
{
    struct dentry *dentry = cstate->current_fh.fh_dentry;

    /*
     * Check about attributes are supported by the NFSv4 server or not.
     * According to spec, unsupported attributes return ERR_ATTRNOTSUPP.
     */
    if ((bmval[0] & ~nfsd_suppattrs0(cstate->minorversion)) ||
        (bmval[1] & ~nfsd_suppattrs1(cstate->minorversion)) ||
        (bmval[2] & ~nfsd_suppattrs2(cstate->minorversion)))
        return nfserr_attrnotsupp;

    /*
     * Check FATTR4_WORD0_ACL can be supported
     * in current environment or not.
     */
    if (bmval[0] & FATTR4_WORD0_ACL) {
        if (!IS_POSIXACL(dentry->d_inode))
            return nfserr_attrnotsupp;
    }

    /*
     * According to spec, read-only attributes return ERR_INVAL.
     */
    if (writable) {
        if ((bmval[0] & ~writable[0]) || (bmval[1] & ~writable[1]) ||
            (bmval[2] & ~writable[2]))
            return nfserr_inval;
    }

    return nfs_ok;
}

static __be32
nfsd4_check_open_attributes(struct svc_rqst *rqstp,
    struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
{
    __be32 status = nfs_ok;

    if (open->op_create == NFS4_OPEN_CREATE) {
        if (open->op_createmode == NFS4_CREATE_UNCHECKED
            || open->op_createmode == NFS4_CREATE_GUARDED)
            status = check_attr_support(rqstp, cstate,
                    open->op_bmval, nfsd_attrmask);
        else if (open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1)
            status = check_attr_support(rqstp, cstate,
                    open->op_bmval, nfsd41_ex_attrmask);
    }

    return status;
}

static int
is_create_with_attrs(struct nfsd4_open *open)
{
    return open->op_create == NFS4_OPEN_CREATE
        && (open->op_createmode == NFS4_CREATE_UNCHECKED
            || open->op_createmode == NFS4_CREATE_GUARDED
            || open->op_createmode == NFS4_CREATE_EXCLUSIVE4_1);
}

/*
 * if error occurs when setting the acl, just clear the acl bit
 * in the returned attr bitmap.
 */
static void
do_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp,
        struct nfs4_acl *acl, u32 *bmval)
{
    __be32 status;

    status = nfsd4_set_nfs4_acl(rqstp, fhp, acl);
    if (status)
        /*
         * We should probably fail the whole open at this point,
         * but we've already created the file, so it's too late;
         * So this seems the least of evils:
         */
        bmval[0] &= ~FATTR4_WORD0_ACL;
}

static inline void
fh_dup2(struct svc_fh *dst, struct svc_fh *src)
{
    fh_put(dst);
    dget(src->fh_dentry);
    if (src->fh_export)
        cache_get(&src->fh_export->h);
    *dst = *src;
}

static __be32
do_open_permission(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open, int accmode)
{
    __be32 status;

    if (open->op_truncate &&
        !(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
        return nfserr_inval;

    accmode |= NFSD_MAY_READ_IF_EXEC;

    if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
        accmode |= NFSD_MAY_READ;
    if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
        accmode |= (NFSD_MAY_WRITE | NFSD_MAY_TRUNC);
    if (open->op_share_deny & NFS4_SHARE_DENY_READ)
        accmode |= NFSD_MAY_WRITE;

    status = fh_verify(rqstp, current_fh, S_IFREG, accmode);

    return status;
}

static __be32 nfsd_check_obj_isreg(struct svc_fh *fh)
{
    umode_t mode = fh->fh_dentry->d_inode->i_mode;

    if (S_ISREG(mode))
        return nfs_ok;
    if (S_ISDIR(mode))
        return nfserr_isdir;
    /*
     * Using err_symlink as our catch-all case may look odd; but
     * there's no other obvious error for this case in 4.0, and we
     * happen to know that it will cause the linux v4 client to do
     * the right thing on attempts to open something other than a
     * regular file.
     */
    return nfserr_symlink;
}

static __be32
do_open_lookup(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
{
    struct svc_fh *resfh;
    __be32 status;

    resfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
    if (!resfh)
        return nfserr_jukebox;
    fh_init(resfh, NFS4_FHSIZE);
    open->op_truncate = 0;

    if (open->op_create) {
        /* FIXME: check session persistence and pnfs flags.
         * The nfsv4.1 spec requires the following semantics:
         *
         * Persistent   | pNFS   | Server REQUIRED | Client Allowed
         * Reply Cache  | server |                 |
         * -------------+--------+-----------------+--------------------
         * no           | no     | EXCLUSIVE4_1    | EXCLUSIVE4_1
         *              |        |                 | (SHOULD)
         *              |        | and EXCLUSIVE4  | or EXCLUSIVE4
         *              |        |                 | (SHOULD NOT)
         * no           | yes    | EXCLUSIVE4_1    | EXCLUSIVE4_1
         * yes          | no     | GUARDED4        | GUARDED4
         * yes          | yes    | GUARDED4        | GUARDED4
         */

        /*
         * Note: create modes (UNCHECKED,GUARDED...) are the same
         * in NFSv4 as in v3 except EXCLUSIVE4_1.
         */
        status = do_nfsd_create(rqstp, current_fh, open->op_fname.data,
                    open->op_fname.len, &open->op_iattr,
                    resfh, open->op_createmode,
                    (u32 *)open->op_verf.data,
                    &open->op_truncate, &open->op_created);

        /*
         * Following rfc 3530 14.2.16, use the returned bitmask
         * to indicate which attributes we used to store the
         * verifier:
         */
        if (open->op_createmode == NFS4_CREATE_EXCLUSIVE && status == 0)
            open->op_bmval[1] = (FATTR4_WORD1_TIME_ACCESS |
                            FATTR4_WORD1_TIME_MODIFY);
    } else {
        status = nfsd_lookup(rqstp, current_fh,
                     open->op_fname.data, open->op_fname.len, resfh);
        fh_unlock(current_fh);
    }
    if (status)
        goto out;
    status = nfsd_check_obj_isreg(resfh);
    if (status)
        goto out;

    if (is_create_with_attrs(open) && open->op_acl != NULL)
        do_set_nfs4_acl(rqstp, resfh, open->op_acl, open->op_bmval);

    /* set reply cache */
    fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
            &resfh->fh_handle);
    if (!open->op_created)
        status = do_open_permission(rqstp, resfh, open,
                        NFSD_MAY_NOP);
    set_change_info(&open->op_cinfo, current_fh);
    fh_dup2(current_fh, resfh);
out:
    fh_put(resfh);
    kfree(resfh);
    return status;
}

static __be32
do_open_fhandle(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
{
    __be32 status;

    /* We don't know the target directory, and therefore can not
    * set the change info
    */

    memset(&open->op_cinfo, 0, sizeof(struct nfsd4_change_info));

    /* set replay cache */
    fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
            &current_fh->fh_handle);

    open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
        (open->op_iattr.ia_size == 0);

    status = do_open_permission(rqstp, current_fh, open,
                    NFSD_MAY_OWNER_OVERRIDE);

    return status;
}

static void
copy_clientid(clientid_t *clid, struct nfsd4_session *session)
{
    struct nfsd4_sessionid *sid =
            (struct nfsd4_sessionid *)session->se_sessionid.data;

    clid->cl_boot = sid->clientid.cl_boot;
    clid->cl_id = sid->clientid.cl_id;
}

static __be32
nfsd4_open(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
       struct nfsd4_open *open)
{
    __be32 status;
    struct nfsd4_compoundres *resp;

    dprintk("NFSD: nfsd4_open filename %.*s op_openowner %p\n",
        (int)open->op_fname.len, open->op_fname.data,
        open->op_openowner);

    /* This check required by spec. */
    if (open->op_create && open->op_claim_type != NFS4_OPEN_CLAIM_NULL)
        return nfserr_inval;

    open->op_created = 0;
    /*
     * RFC5661 18.51.3
     * Before RECLAIM_COMPLETE done, server should deny new lock
     */
    if (nfsd4_has_session(cstate) &&
        !test_bit(NFSD4_CLIENT_RECLAIM_COMPLETE,
              &cstate->session->se_client->cl_flags) &&
        open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
        return nfserr_grace;

    if (nfsd4_has_session(cstate))
        copy_clientid(&open->op_clientid, cstate->session);

    nfs4_lock_state();

    /* check seqid for replay. set nfs4_owner */
    resp = rqstp->rq_resp;
    status = nfsd4_process_open1(&resp->cstate, open);
    if (status == nfserr_replay_me) {
        struct nfs4_replay *rp = &open->op_openowner->oo_owner.so_replay;
        fh_put(&cstate->current_fh);
        fh_copy_shallow(&cstate->current_fh.fh_handle,
                &rp->rp_openfh);
        status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
        if (status)
            dprintk("nfsd4_open: replay failed"
                " restoring previous filehandle\n");
        else
            status = nfserr_replay_me;
    }
    if (status)
        goto out;

    status = nfsd4_check_open_attributes(rqstp, cstate, open);
    if (status)
        goto out;

    /* Openowner is now set, so sequence id will get bumped.  Now we need
     * these checks before we do any creates: */
    status = nfserr_grace;
    if (locks_in_grace(SVC_NET(rqstp)) && open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
        goto out;
    status = nfserr_no_grace;
    if (!locks_in_grace(SVC_NET(rqstp)) && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
        goto out;

    switch (open->op_claim_type) {
        case NFS4_OPEN_CLAIM_DELEGATE_CUR:
        case NFS4_OPEN_CLAIM_NULL:
            status = do_open_lookup(rqstp, &cstate->current_fh,
                        open);
            if (status)
                goto out;
            break;
        case NFS4_OPEN_CLAIM_PREVIOUS:
            open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
            status = nfs4_check_open_reclaim(&open->op_clientid, cstate->minorversion);
            if (status)
                goto out;
        case NFS4_OPEN_CLAIM_FH:
        case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
            status = do_open_fhandle(rqstp, &cstate->current_fh,
                         open);
            if (status)
                goto out;
            break;
        case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
                case NFS4_OPEN_CLAIM_DELEGATE_PREV:
            open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
            dprintk("NFSD: unsupported OPEN claim type %d\n",
                open->op_claim_type);
            status = nfserr_notsupp;
            goto out;
        default:
            dprintk("NFSD: Invalid OPEN claim type %d\n",
                open->op_claim_type);
            status = nfserr_inval;
            goto out;
    }
    /*
     * nfsd4_process_open2() does the actual opening of the file.  If
     * successful, it (1) truncates the file if open->op_truncate was
     * set, (2) sets open->op_stateid, (3) sets open->op_delegation.
     */
    status = nfsd4_process_open2(rqstp, &cstate->current_fh, open);
    WARN_ON(status && open->op_created);
out:
    nfsd4_cleanup_open_state(open, status);
    if (open->op_openowner)
        cstate->replay_owner = &open->op_openowner->oo_owner;
    else
        nfs4_unlock_state();
    return status;
}

/*
 * filehandle-manipulating ops.
 */
static __be32
nfsd4_getfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        struct svc_fh **getfh)
{
    if (!cstate->current_fh.fh_dentry)
        return nfserr_nofilehandle;

    *getfh = &cstate->current_fh;
    return nfs_ok;
}

static __be32
nfsd4_putfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        struct nfsd4_putfh *putfh)
{
    fh_put(&cstate->current_fh);
    cstate->current_fh.fh_handle.fh_size = putfh->pf_fhlen;
    memcpy(&cstate->current_fh.fh_handle.fh_base, putfh->pf_fhval,
           putfh->pf_fhlen);
    return fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_BYPASS_GSS);
}

static __be32
nfsd4_putrootfh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        void *arg)
{
    __be32 status;

    fh_put(&cstate->current_fh);
    status = exp_pseudoroot(rqstp, &cstate->current_fh);
    return status;
}

static __be32
nfsd4_restorefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        void *arg)
{
    if (!cstate->save_fh.fh_dentry)
        return nfserr_restorefh;

    fh_dup2(&cstate->current_fh, &cstate->save_fh);
    if (HAS_STATE_ID(cstate, SAVED_STATE_ID_FLAG)) {
        memcpy(&cstate->current_stateid, &cstate->save_stateid, sizeof(stateid_t));
        SET_STATE_ID(cstate, CURRENT_STATE_ID_FLAG);
    }
    return nfs_ok;
}

static __be32
nfsd4_savefh(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         void *arg)
{
    if (!cstate->current_fh.fh_dentry)
        return nfserr_nofilehandle;

    fh_dup2(&cstate->save_fh, &cstate->current_fh);
    if (HAS_STATE_ID(cstate, CURRENT_STATE_ID_FLAG)) {
        memcpy(&cstate->save_stateid, &cstate->current_stateid, sizeof(stateid_t));
        SET_STATE_ID(cstate, SAVED_STATE_ID_FLAG);
    }
    return nfs_ok;
}

/*
 * misc nfsv4 ops
 */
static __be32
nfsd4_access(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_access *access)
{
    if (access->ac_req_access & ~NFS3_ACCESS_FULL)
        return nfserr_inval;

    access->ac_resp_access = access->ac_req_access;
    return nfsd_access(rqstp, &cstate->current_fh, &access->ac_resp_access,
               &access->ac_supported);
}

static void gen_boot_verifier(nfs4_verifier *verifier)
{
    __be32 verf[2];

    verf[0] = (__be32)nfssvc_boot.tv_sec;
    verf[1] = (__be32)nfssvc_boot.tv_usec;
    memcpy(verifier->data, verf, sizeof(verifier->data));
}

static __be32
nfsd4_commit(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_commit *commit)
{
    gen_boot_verifier(&commit->co_verf);
    return nfsd_commit(rqstp, &cstate->current_fh, commit->co_offset,
                 commit->co_count);
}

static __be32
nfsd4_create(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_create *create)
{
    struct svc_fh resfh;
    __be32 status;
    dev_t rdev;

    fh_init(&resfh, NFS4_FHSIZE);

    status = fh_verify(rqstp, &cstate->current_fh, S_IFDIR,
               NFSD_MAY_CREATE);
    if (status)
        return status;

    status = check_attr_support(rqstp, cstate, create->cr_bmval,
                    nfsd_attrmask);
    if (status)
        return status;

    switch (create->cr_type) {
    case NF4LNK:
        /* ugh! we have to null-terminate the linktext, or
         * vfs_symlink() will choke.  it is always safe to
         * null-terminate by brute force, since at worst we
         * will overwrite the first byte of the create namelen
         * in the XDR buffer, which has already been extracted
         * during XDR decode.
         */
        create->cr_linkname[create->cr_linklen] = 0;

        status = nfsd_symlink(rqstp, &cstate->current_fh,
                      create->cr_name, create->cr_namelen,
                      create->cr_linkname, create->cr_linklen,
                      &resfh, &create->cr_iattr);
        break;

    case NF4BLK:
        rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
        if (MAJOR(rdev) != create->cr_specdata1 ||
            MINOR(rdev) != create->cr_specdata2)
            return nfserr_inval;
        status = nfsd_create(rqstp, &cstate->current_fh,
                     create->cr_name, create->cr_namelen,
                     &create->cr_iattr, S_IFBLK, rdev, &resfh);
        break;

    case NF4CHR:
        rdev = MKDEV(create->cr_specdata1, create->cr_specdata2);
        if (MAJOR(rdev) != create->cr_specdata1 ||
            MINOR(rdev) != create->cr_specdata2)
            return nfserr_inval;
        status = nfsd_create(rqstp, &cstate->current_fh,
                     create->cr_name, create->cr_namelen,
                     &create->cr_iattr,S_IFCHR, rdev, &resfh);
        break;

    case NF4SOCK:
        status = nfsd_create(rqstp, &cstate->current_fh,
                     create->cr_name, create->cr_namelen,
                     &create->cr_iattr, S_IFSOCK, 0, &resfh);
        break;

    case NF4FIFO:
        status = nfsd_create(rqstp, &cstate->current_fh,
                     create->cr_name, create->cr_namelen,
                     &create->cr_iattr, S_IFIFO, 0, &resfh);
        break;

    case NF4DIR:
        create->cr_iattr.ia_valid &= ~ATTR_SIZE;
        status = nfsd_create(rqstp, &cstate->current_fh,
                     create->cr_name, create->cr_namelen,
                     &create->cr_iattr, S_IFDIR, 0, &resfh);
        break;

    default:
        status = nfserr_badtype;
    }

    if (status)
        goto out;

    if (create->cr_acl != NULL)
        do_set_nfs4_acl(rqstp, &resfh, create->cr_acl,
                create->cr_bmval);

    fh_unlock(&cstate->current_fh);
    set_change_info(&create->cr_cinfo, &cstate->current_fh);
    fh_dup2(&cstate->current_fh, &resfh);
out:
    fh_put(&resfh);
    return status;
}

static __be32
nfsd4_getattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_getattr *getattr)
{
    __be32 status;

    status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
    if (status)
        return status;

    if (getattr->ga_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
        return nfserr_inval;

    getattr->ga_bmval[0] &= nfsd_suppattrs0(cstate->minorversion);
    getattr->ga_bmval[1] &= nfsd_suppattrs1(cstate->minorversion);
    getattr->ga_bmval[2] &= nfsd_suppattrs2(cstate->minorversion);

    getattr->ga_fhp = &cstate->current_fh;
    return nfs_ok;
}

static __be32
nfsd4_link(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
       struct nfsd4_link *link)
{
    __be32 status = nfserr_nofilehandle;

    if (!cstate->save_fh.fh_dentry)
        return status;
    status = nfsd_link(rqstp, &cstate->current_fh,
               link->li_name, link->li_namelen, &cstate->save_fh);
    if (!status)
        set_change_info(&link->li_cinfo, &cstate->current_fh);
    return status;
}

static __be32 nfsd4_do_lookupp(struct svc_rqst *rqstp, struct svc_fh *fh)
{
    struct svc_fh tmp_fh;
    __be32 ret;

    fh_init(&tmp_fh, NFS4_FHSIZE);
    ret = exp_pseudoroot(rqstp, &tmp_fh);
    if (ret)
        return ret;
    if (tmp_fh.fh_dentry == fh->fh_dentry) {
        fh_put(&tmp_fh);
        return nfserr_noent;
    }
    fh_put(&tmp_fh);
    return nfsd_lookup(rqstp, fh, "..", 2, fh);
}

static __be32
nfsd4_lookupp(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          void *arg)
{
    return nfsd4_do_lookupp(rqstp, &cstate->current_fh);
}

static __be32
nfsd4_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_lookup *lookup)
{
    return nfsd_lookup(rqstp, &cstate->current_fh,
               lookup->lo_name, lookup->lo_len,
               &cstate->current_fh);
}

static __be32
nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
       struct nfsd4_read *read)
{
    __be32 status;

    /* no need to check permission - this will be done in nfsd_read() */

    read->rd_filp = NULL;
    if (read->rd_offset >= OFFSET_MAX)
        return nfserr_inval;

    nfs4_lock_state();
    /* check stateid */
    if ((status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
                         cstate, &read->rd_stateid,
                         RD_STATE, &read->rd_filp))) {
        dprintk("NFSD: nfsd4_read: couldn't process stateid!\n");
        goto out;
    }
    if (read->rd_filp)
        get_file(read->rd_filp);
    status = nfs_ok;
out:
    nfs4_unlock_state();
    read->rd_rqstp = rqstp;
    read->rd_fhp = &cstate->current_fh;
    return status;
}

static __be32
nfsd4_readdir(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_readdir *readdir)
{
    u64 cookie = readdir->rd_cookie;
    static const nfs4_verifier zeroverf;

    /* no need to check permission - this will be done in nfsd_readdir() */

    if (readdir->rd_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1)
        return nfserr_inval;

    readdir->rd_bmval[0] &= nfsd_suppattrs0(cstate->minorversion);
    readdir->rd_bmval[1] &= nfsd_suppattrs1(cstate->minorversion);
    readdir->rd_bmval[2] &= nfsd_suppattrs2(cstate->minorversion);

    if ((cookie == 1) || (cookie == 2) ||
        (cookie == 0 && memcmp(readdir->rd_verf.data, zeroverf.data, NFS4_VERIFIER_SIZE)))
        return nfserr_bad_cookie;

    readdir->rd_rqstp = rqstp;
    readdir->rd_fhp = &cstate->current_fh;
    return nfs_ok;
}

static __be32
nfsd4_readlink(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
           struct nfsd4_readlink *readlink)
{
    readlink->rl_rqstp = rqstp;
    readlink->rl_fhp = &cstate->current_fh;
    return nfs_ok;
}

static __be32
nfsd4_remove(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_remove *remove)
{
    __be32 status;

    if (locks_in_grace(SVC_NET(rqstp)))
        return nfserr_grace;
    status = nfsd_unlink(rqstp, &cstate->current_fh, 0,
                 remove->rm_name, remove->rm_namelen);
    if (!status) {
        fh_unlock(&cstate->current_fh);
        set_change_info(&remove->rm_cinfo, &cstate->current_fh);
    }
    return status;
}

static __be32
nfsd4_rename(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_rename *rename)
{
    __be32 status = nfserr_nofilehandle;

    if (!cstate->save_fh.fh_dentry)
        return status;
    if (locks_in_grace(SVC_NET(rqstp)) &&
        !(cstate->save_fh.fh_export->ex_flags & NFSEXP_NOSUBTREECHECK))
        return nfserr_grace;
    status = nfsd_rename(rqstp, &cstate->save_fh, rename->rn_sname,
                 rename->rn_snamelen, &cstate->current_fh,
                 rename->rn_tname, rename->rn_tnamelen);

    /* the underlying filesystem returns different error's than required
     * by NFSv4. both save_fh and current_fh have been verified.. */
    if (status == nfserr_isdir)
        status = nfserr_exist;
    else if ((status == nfserr_notdir) &&
                  (S_ISDIR(cstate->save_fh.fh_dentry->d_inode->i_mode) &&
                   S_ISDIR(cstate->current_fh.fh_dentry->d_inode->i_mode)))
        status = nfserr_exist;

    if (!status) {
        set_change_info(&rename->rn_sinfo, &cstate->current_fh);
        set_change_info(&rename->rn_tinfo, &cstate->save_fh);
    }
    return status;
}

static __be32
nfsd4_secinfo(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_secinfo *secinfo)
{
    struct svc_fh resfh;
    struct svc_export *exp;
    struct dentry *dentry;
    __be32 err;

    fh_init(&resfh, NFS4_FHSIZE);
    err = fh_verify(rqstp, &cstate->current_fh, S_IFDIR, NFSD_MAY_EXEC);
    if (err)
        return err;
    err = nfsd_lookup_dentry(rqstp, &cstate->current_fh,
                    secinfo->si_name, secinfo->si_namelen,
                    &exp, &dentry);
    if (err)
        return err;
    if (dentry->d_inode == NULL) {
        exp_put(exp);
        err = nfserr_noent;
    } else
        secinfo->si_exp = exp;
    dput(dentry);
    if (cstate->minorversion)
        /* See rfc 5661 section 2.6.3.1.1.8 */
        fh_put(&cstate->current_fh);
    return err;
}

static __be32
nfsd4_secinfo_no_name(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_secinfo_no_name *sin)
{
    __be32 err;

    switch (sin->sin_style) {
    case NFS4_SECINFO_STYLE4_CURRENT_FH:
        break;
    case NFS4_SECINFO_STYLE4_PARENT:
        err = nfsd4_do_lookupp(rqstp, &cstate->current_fh);
        if (err)
            return err;
        break;
    default:
        return nfserr_inval;
    }
    exp_get(cstate->current_fh.fh_export);
    sin->sin_exp = cstate->current_fh.fh_export;
    fh_put(&cstate->current_fh);
    return nfs_ok;
}

static __be32
nfsd4_setattr(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_setattr *setattr)
{
    __be32 status = nfs_ok;
    int err;

    if (setattr->sa_iattr.ia_valid & ATTR_SIZE) {
        nfs4_lock_state();
        status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
            &setattr->sa_stateid, WR_STATE, NULL);
        nfs4_unlock_state();
        if (status) {
            dprintk("NFSD: nfsd4_setattr: couldn't process stateid!\n");
            return status;
        }
    }
    err = fh_want_write(&cstate->current_fh);
    if (err)
        return nfserrno(err);
    status = nfs_ok;

    status = check_attr_support(rqstp, cstate, setattr->sa_bmval,
                    nfsd_attrmask);
    if (status)
        goto out;

    if (setattr->sa_acl != NULL)
        status = nfsd4_set_nfs4_acl(rqstp, &cstate->current_fh,
                        setattr->sa_acl);
    if (status)
        goto out;
    status = nfsd_setattr(rqstp, &cstate->current_fh, &setattr->sa_iattr,
                0, (time_t)0);
out:
    fh_drop_write(&cstate->current_fh);
    return status;
}

static __be32
nfsd4_write(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
        struct nfsd4_write *write)
{
    stateid_t *stateid = &write->wr_stateid;
    struct file *filp = NULL;
    __be32 status = nfs_ok;
    unsigned long cnt;

    /* no need to check permission - this will be done in nfsd_write() */

    if (write->wr_offset >= OFFSET_MAX)
        return nfserr_inval;

    nfs4_lock_state();
    status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
                    cstate, stateid, WR_STATE, &filp);
    if (filp)
        get_file(filp);
    nfs4_unlock_state();

    if (status) {
        dprintk("NFSD: nfsd4_write: couldn't process stateid!\n");
        return status;
    }

    cnt = write->wr_buflen;
    write->wr_how_written = write->wr_stable_how;
    gen_boot_verifier(&write->wr_verifier);

    status =  nfsd_write(rqstp, &cstate->current_fh, filp,
                 write->wr_offset, rqstp->rq_vec, write->wr_vlen,
                 &cnt, &write->wr_how_written);
    if (filp)
        fput(filp);

    write->wr_bytes_written = cnt;

    return status;
}

/* This routine never returns NFS_OK!  If there are no other errors, it
 * will return NFSERR_SAME or NFSERR_NOT_SAME depending on whether the
 * attributes matched.  VERIFY is implemented by mapping NFSERR_SAME
 * to NFS_OK after the call; NVERIFY by mapping NFSERR_NOT_SAME to NFS_OK.
 */
static __be32
_nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_verify *verify)
{
    __be32 *buf, *p;
    int count;
    __be32 status;

    status = fh_verify(rqstp, &cstate->current_fh, 0, NFSD_MAY_NOP);
    if (status)
        return status;

    status = check_attr_support(rqstp, cstate, verify->ve_bmval, NULL);
    if (status)
        return status;

    if ((verify->ve_bmval[0] & FATTR4_WORD0_RDATTR_ERROR)
        || (verify->ve_bmval[1] & NFSD_WRITEONLY_ATTRS_WORD1))
        return nfserr_inval;
    if (verify->ve_attrlen & 3)
        return nfserr_inval;

    /* count in words:
     *   bitmap_len(1) + bitmap(2) + attr_len(1) = 4
     */
    count = 4 + (verify->ve_attrlen >> 2);
    buf = kmalloc(count << 2, GFP_KERNEL);
    if (!buf)
        return nfserr_jukebox;

    status = nfsd4_encode_fattr(&cstate->current_fh,
                    cstate->current_fh.fh_export,
                    cstate->current_fh.fh_dentry, buf,
                    &count, verify->ve_bmval,
                    rqstp, 0);

    /* this means that nfsd4_encode_fattr() ran out of space */
    if (status == nfserr_resource && count == 0)
        status = nfserr_not_same;
    if (status)
        goto out_kfree;

    /* skip bitmap */
    p = buf + 1 + ntohl(buf[0]);
    status = nfserr_not_same;
    if (ntohl(*p++) != verify->ve_attrlen)
        goto out_kfree;
    if (!memcmp(p, verify->ve_attrval, verify->ve_attrlen))
        status = nfserr_same;

out_kfree:
    kfree(buf);
    return status;
}

static __be32
nfsd4_nverify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
          struct nfsd4_verify *verify)
{
    __be32 status;

    status = _nfsd4_verify(rqstp, cstate, verify);
    return status == nfserr_not_same ? nfs_ok : status;
}

static __be32
nfsd4_verify(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
         struct nfsd4_verify *verify)
{
    __be32 status;

    status = _nfsd4_verify(rqstp, cstate, verify);
    return status == nfserr_same ? nfs_ok : status;
}

/*
 * NULL call.
 */
static __be32
nfsd4_proc_null(struct svc_rqst *rqstp, void *argp, void *resp)
{
    return nfs_ok;
}

static inline void nfsd4_increment_op_stats(u32 opnum)
{
    if (opnum >= FIRST_NFS4_OP && opnum <= LAST_NFS4_OP)
        nfsdstats.nfs4_opcount[opnum]++;
}

typedef __be32(*nfsd4op_func)(struct svc_rqst *, struct nfsd4_compound_state *,
                  void *);
typedef u32(*nfsd4op_rsize)(struct svc_rqst *, struct nfsd4_op *op);
typedef void(*stateid_setter)(struct nfsd4_compound_state *, void *);
typedef void(*stateid_getter)(struct nfsd4_compound_state *, void *);

enum nfsd4_op_flags {
    ALLOWED_WITHOUT_FH = 1 << 0,    /* No current filehandle required */
    ALLOWED_ON_ABSENT_FS = 1 << 1,  /* ops processed on absent fs */
    ALLOWED_AS_FIRST_OP = 1 << 2,   /* ops reqired first in compound */
    /* For rfc 5661 section 2.6.3.1.1: */
    OP_HANDLES_WRONGSEC = 1 << 3,
    OP_IS_PUTFH_LIKE = 1 << 4,
    /*
     * These are the ops whose result size we estimate before
     * encoding, to avoid performing an op then not being able to
     * respond or cache a response.  This includes writes and setattrs
     * as well as the operations usually called "nonidempotent":
     */
    OP_MODIFIES_SOMETHING = 1 << 5,
    /*
     * Cache compounds containing these ops in the xid-based drc:
     * We use the DRC for compounds containing non-idempotent
     * operations, *except* those that are 4.1-specific (since
     * sessions provide their own EOS), and except for stateful
     * operations other than setclientid and setclientid_confirm
     * (since sequence numbers provide EOS for open, lock, etc in
     * the v4.0 case).
     */
    OP_CACHEME = 1 << 6,
    /*
     * These are ops which clear current state id.
     */
    OP_CLEAR_STATEID = 1 << 7,
};

struct nfsd4_operation {
    nfsd4op_func op_func;
    u32 op_flags;
    char *op_name;
    /* Try to get response size before operation */
    nfsd4op_rsize op_rsize_bop;
    stateid_getter op_get_currentstateid;
    stateid_setter op_set_currentstateid;
};

static struct nfsd4_operation nfsd4_ops[];

#ifdef NFSD_DEBUG
static const char *nfsd4_op_name(unsigned opnum);
#endif

/*
 * Enforce NFSv4.1 COMPOUND ordering rules:
 *
 * Also note, enforced elsewhere:
 *  - SEQUENCE other than as first op results in
 *    NFS4ERR_SEQUENCE_POS. (Enforced in nfsd4_sequence().)
 *  - BIND_CONN_TO_SESSION must be the only op in its compound.
 *    (Enforced in nfsd4_bind_conn_to_session().)
 *  - DESTROY_SESSION must be the final operation in a compound, if
 *    sessionid's in SEQUENCE and DESTROY_SESSION are the same.
 *    (Enforced in nfsd4_destroy_session().)
 */
static __be32 nfs41_check_op_ordering(struct nfsd4_compoundargs *args)
{
    struct nfsd4_op *op = &args->ops[0];

    /* These ordering requirements don't apply to NFSv4.0: */
    if (args->minorversion == 0)
        return nfs_ok;
    /* This is weird, but OK, not our problem: */
    if (args->opcnt == 0)
        return nfs_ok;
    if (op->status == nfserr_op_illegal)
        return nfs_ok;
    if (!(nfsd4_ops[op->opnum].op_flags & ALLOWED_AS_FIRST_OP))
        return nfserr_op_not_in_session;
    if (op->opnum == OP_SEQUENCE)
        return nfs_ok;
    if (args->opcnt != 1)
        return nfserr_not_only_op;
    return nfs_ok;
}

static inline struct nfsd4_operation *OPDESC(struct nfsd4_op *op)
{
    return &nfsd4_ops[op->opnum];
}

bool nfsd4_cache_this_op(struct nfsd4_op *op)
{
    return OPDESC(op)->op_flags & OP_CACHEME;
}

static bool need_wrongsec_check(struct svc_rqst *rqstp)
{
    struct nfsd4_compoundres *resp = rqstp->rq_resp;
    struct nfsd4_compoundargs *argp = rqstp->rq_argp;
    struct nfsd4_op *this = &argp->ops[resp->opcnt - 1];
    struct nfsd4_op *next = &argp->ops[resp->opcnt];
    struct nfsd4_operation *thisd;
    struct nfsd4_operation *nextd;

    thisd = OPDESC(this);
    /*
     * Most ops check wronsec on our own; only the putfh-like ops
     * have special rules.
     */
    if (!(thisd->op_flags & OP_IS_PUTFH_LIKE))
        return false;
    /*
     * rfc 5661 2.6.3.1.1.6: don't bother erroring out a
     * put-filehandle operation if we're not going to use the
     * result:
     */
    if (argp->opcnt == resp->opcnt)
        return false;

    nextd = OPDESC(next);
    /*
     * Rest of 2.6.3.1.1: certain operations will return WRONGSEC
     * errors themselves as necessary; others should check for them
     * now:
     */
    return !(nextd->op_flags & OP_HANDLES_WRONGSEC);
}

/*
 * COMPOUND call.
 */
static __be32
nfsd4_proc_compound(struct svc_rqst *rqstp,
            struct nfsd4_compoundargs *args,
            struct nfsd4_compoundres *resp)
{
    struct nfsd4_op *op;
    struct nfsd4_operation *opdesc;
    struct nfsd4_compound_state *cstate = &resp->cstate;
    int     slack_bytes;
    u32     plen = 0;
    __be32      status;

    resp->xbuf = &rqstp->rq_res;
    resp->p = rqstp->rq_res.head[0].iov_base +
                        rqstp->rq_res.head[0].iov_len;
    resp->tagp = resp->p;
    /* reserve space for: taglen, tag, and opcnt */
    resp->p += 2 + XDR_QUADLEN(args->taglen);
    resp->end = rqstp->rq_res.head[0].iov_base + PAGE_SIZE;
    resp->taglen = args->taglen;
    resp->tag = args->tag;
    resp->opcnt = 0;
    resp->rqstp = rqstp;
    resp->cstate.minorversion = args->minorversion;
    resp->cstate.replay_owner = NULL;
    resp->cstate.session = NULL;
    fh_init(&resp->cstate.current_fh, NFS4_FHSIZE);
    fh_init(&resp->cstate.save_fh, NFS4_FHSIZE);
    /*
     * Don't use the deferral mechanism for NFSv4; compounds make it
     * too hard to avoid non-idempotency problems.
     */
    rqstp->rq_usedeferral = 0;

    /*
     * According to RFC3010, this takes precedence over all other errors.
     */
    status = nfserr_minor_vers_mismatch;
    if (args->minorversion > nfsd_supported_minorversion)
        goto out;

    status = nfs41_check_op_ordering(args);
    if (status) {
        op = &args->ops[0];
        op->status = status;
        goto encode_op;
    }

    while (!status && resp->opcnt < args->opcnt) {
        op = &args->ops[resp->opcnt++];

        dprintk("nfsv4 compound op #%d/%d: %d (%s)\n",
            resp->opcnt, args->opcnt, op->opnum,
            nfsd4_op_name(op->opnum));
        /*
         * The XDR decode routines may have pre-set op->status;
         * for example, if there is a miscellaneous XDR error
         * it will be set to nfserr_bad_xdr.
         */
        if (op->status)
            goto encode_op;

        /* We must be able to encode a successful response to
         * this operation, with enough room left over to encode a
         * failed response to the next operation.  If we don't
         * have enough room, fail with ERR_RESOURCE.
         */
        slack_bytes = (char *)resp->end - (char *)resp->p;
        if (slack_bytes < COMPOUND_SLACK_SPACE
                + COMPOUND_ERR_SLACK_SPACE) {
            BUG_ON(slack_bytes < COMPOUND_ERR_SLACK_SPACE);
            op->status = nfserr_resource;
            goto encode_op;
        }

        opdesc = OPDESC(op);

        if (!cstate->current_fh.fh_dentry) {
            if (!(opdesc->op_flags & ALLOWED_WITHOUT_FH)) {
                op->status = nfserr_nofilehandle;
                goto encode_op;
            }
        } else if (cstate->current_fh.fh_export->ex_fslocs.migrated &&
              !(opdesc->op_flags & ALLOWED_ON_ABSENT_FS)) {
            op->status = nfserr_moved;
            goto encode_op;
        }

        /* If op is non-idempotent */
        if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
            plen = opdesc->op_rsize_bop(rqstp, op);
            op->status = nfsd4_check_resp_size(resp, plen);
        }

        if (op->status)
            goto encode_op;

        if (opdesc->op_func) {
            if (opdesc->op_get_currentstateid)
                opdesc->op_get_currentstateid(cstate, &op->u);
            op->status = opdesc->op_func(rqstp, cstate, &op->u);
        } else
            BUG_ON(op->status == nfs_ok);

        if (!op->status) {
            if (opdesc->op_set_currentstateid)
                opdesc->op_set_currentstateid(cstate, &op->u);

            if (opdesc->op_flags & OP_CLEAR_STATEID)
                clear_current_stateid(cstate);

            if (need_wrongsec_check(rqstp))
                op->status = check_nfsd_access(cstate->current_fh.fh_export, rqstp);
        }

encode_op:
        /* Only from SEQUENCE */
        if (resp->cstate.status == nfserr_replay_cache) {
            dprintk("%s NFS4.1 replay from cache\n", __func__);
            status = op->status;
            goto out;
        }
        if (op->status == nfserr_replay_me) {
            op->replay = &cstate->replay_owner->so_replay;
            nfsd4_encode_replay(resp, op);
            status = op->status = op->replay->rp_status;
        } else {
            nfsd4_encode_operation(resp, op);
            status = op->status;
        }

        dprintk("nfsv4 compound op %p opcnt %d #%d: %d: status %d\n",
            args->ops, args->opcnt, resp->opcnt, op->opnum,
            be32_to_cpu(status));

        if (cstate->replay_owner) {
            nfs4_unlock_state();
            cstate->replay_owner = NULL;
        }
        /* XXX Ugh, we need to get rid of this kind of special case: */
        if (op->opnum == OP_READ && op->u.read.rd_filp)
            fput(op->u.read.rd_filp);

        nfsd4_increment_op_stats(op->opnum);
    }

    resp->cstate.status = status;
    fh_put(&resp->cstate.current_fh);
    fh_put(&resp->cstate.save_fh);
    BUG_ON(resp->cstate.replay_owner);
out:
    /* Reset deferral mechanism for RPC deferrals */
    rqstp->rq_usedeferral = 1;
    dprintk("nfsv4 compound returned %d\n", ntohl(status));
    return status;
}

#define op_encode_hdr_size      (2)
#define op_encode_stateid_maxsz     (XDR_QUADLEN(NFS4_STATEID_SIZE))
#define op_encode_verifier_maxsz    (XDR_QUADLEN(NFS4_VERIFIER_SIZE))
#define op_encode_change_info_maxsz (5)
#define nfs4_fattr_bitmap_maxsz     (4)

#define op_encode_lockowner_maxsz   (1 + XDR_QUADLEN(IDMAP_NAMESZ))
#define op_encode_lock_denied_maxsz (8 + op_encode_lockowner_maxsz)

#define nfs4_owner_maxsz        (1 + XDR_QUADLEN(IDMAP_NAMESZ))

#define op_encode_ace_maxsz     (3 + nfs4_owner_maxsz)
#define op_encode_delegation_maxsz  (1 + op_encode_stateid_maxsz + 1 + \
                     op_encode_ace_maxsz)

#define op_encode_channel_attrs_maxsz   (6 + 1 + 1)

static inline u32 nfsd4_only_status_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size) * sizeof(__be32);
}

static inline u32 nfsd4_status_stateid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_stateid_maxsz)* sizeof(__be32);
}

static inline u32 nfsd4_commit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_create_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_change_info_maxsz
        + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_link_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_change_info_maxsz)
        * sizeof(__be32);
}

static inline u32 nfsd4_lock_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_lock_denied_maxsz)
        * sizeof(__be32);
}

static inline u32 nfsd4_open_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_stateid_maxsz
        + op_encode_change_info_maxsz + 1
        + nfs4_fattr_bitmap_maxsz
        + op_encode_delegation_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_read_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    u32 maxcount = 0, rlen = 0;

    maxcount = svc_max_payload(rqstp);
    rlen = op->u.read.rd_length;

    if (rlen > maxcount)
        rlen = maxcount;

    return (op_encode_hdr_size + 2) * sizeof(__be32) + rlen;
}

static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    u32 rlen = op->u.readdir.rd_maxcount;

    if (rlen > PAGE_SIZE)
        rlen = PAGE_SIZE;

    return (op_encode_hdr_size + op_encode_verifier_maxsz)
         * sizeof(__be32) + rlen;
}

static inline u32 nfsd4_remove_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_change_info_maxsz)
        * sizeof(__be32);
}

static inline u32 nfsd4_rename_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_change_info_maxsz
        + op_encode_change_info_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_setattr_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + nfs4_fattr_bitmap_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_setclientid_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + 2 + 1024) * sizeof(__be32);
}

static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + op_encode_verifier_maxsz) * sizeof(__be32);
}

static inline u32 nfsd4_exchange_id_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + 2 + 1 + /* eir_clientid, eir_sequenceid */\
        1 + 1 + 0 + /* eir_flags, spr_how, SP4_NONE (for now) */\
        2 + /*eir_server_owner.so_minor_id */\
        /* eir_server_owner.so_major_id<> */\
        XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
        /* eir_server_scope<> */\
        XDR_QUADLEN(NFS4_OPAQUE_LIMIT) + 1 +\
        1 + /* eir_server_impl_id array length */\
        0 /* ignored eir_server_impl_id contents */) * sizeof(__be32);
}

static inline u32 nfsd4_bind_conn_to_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + \
        XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* bctsr_sessid */\
        2 /* bctsr_dir, use_conn_in_rdma_mode */) * sizeof(__be32);
}

static inline u32 nfsd4_create_session_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
    return (op_encode_hdr_size + \
        XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + /* sessionid */\
        2 + /* csr_sequence, csr_flags */\
        op_encode_channel_attrs_maxsz + \
        op_encode_channel_attrs_maxsz) * sizeof(__be32);
}

static struct nfsd4_operation nfsd4_ops[] = {
    [OP_ACCESS] = {
        .op_func = (nfsd4op_func)nfsd4_access,
        .op_name = "OP_ACCESS",
    },
    [OP_CLOSE] = {
        .op_func = (nfsd4op_func)nfsd4_close,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_CLOSE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_closestateid,
        .op_set_currentstateid = (stateid_setter)nfsd4_set_closestateid,
    },
    [OP_COMMIT] = {
        .op_func = (nfsd4op_func)nfsd4_commit,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_COMMIT",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_commit_rsize,
    },
    [OP_CREATE] = {
        .op_func = (nfsd4op_func)nfsd4_create,
        .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME | OP_CLEAR_STATEID,
        .op_name = "OP_CREATE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_create_rsize,
    },
    [OP_DELEGRETURN] = {
        .op_func = (nfsd4op_func)nfsd4_delegreturn,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_DELEGRETURN",
        .op_rsize_bop = nfsd4_only_status_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_delegreturnstateid,
    },
    [OP_GETATTR] = {
        .op_func = (nfsd4op_func)nfsd4_getattr,
        .op_flags = ALLOWED_ON_ABSENT_FS,
        .op_name = "OP_GETATTR",
    },
    [OP_GETFH] = {
        .op_func = (nfsd4op_func)nfsd4_getfh,
        .op_name = "OP_GETFH",
    },
    [OP_LINK] = {
        .op_func = (nfsd4op_func)nfsd4_link,
        .op_flags = ALLOWED_ON_ABSENT_FS | OP_MODIFIES_SOMETHING
                | OP_CACHEME,
        .op_name = "OP_LINK",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_link_rsize,
    },
    [OP_LOCK] = {
        .op_func = (nfsd4op_func)nfsd4_lock,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_LOCK",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_lock_rsize,
        .op_set_currentstateid = (stateid_setter)nfsd4_set_lockstateid,
    },
    [OP_LOCKT] = {
        .op_func = (nfsd4op_func)nfsd4_lockt,
        .op_name = "OP_LOCKT",
    },
    [OP_LOCKU] = {
        .op_func = (nfsd4op_func)nfsd4_locku,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_LOCKU",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_lockustateid,
    },
    [OP_LOOKUP] = {
        .op_func = (nfsd4op_func)nfsd4_lookup,
        .op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
        .op_name = "OP_LOOKUP",
    },
    [OP_LOOKUPP] = {
        .op_func = (nfsd4op_func)nfsd4_lookupp,
        .op_flags = OP_HANDLES_WRONGSEC | OP_CLEAR_STATEID,
        .op_name = "OP_LOOKUPP",
    },
    [OP_NVERIFY] = {
        .op_func = (nfsd4op_func)nfsd4_nverify,
        .op_name = "OP_NVERIFY",
    },
    [OP_OPEN] = {
        .op_func = (nfsd4op_func)nfsd4_open,
        .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
        .op_name = "OP_OPEN",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_open_rsize,
        .op_set_currentstateid = (stateid_setter)nfsd4_set_openstateid,
    },
    [OP_OPEN_CONFIRM] = {
        .op_func = (nfsd4op_func)nfsd4_open_confirm,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_OPEN_CONFIRM",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
    },
    [OP_OPEN_DOWNGRADE] = {
        .op_func = (nfsd4op_func)nfsd4_open_downgrade,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_OPEN_DOWNGRADE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_status_stateid_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_opendowngradestateid,
        .op_set_currentstateid = (stateid_setter)nfsd4_set_opendowngradestateid,
    },
    [OP_PUTFH] = {
        .op_func = (nfsd4op_func)nfsd4_putfh,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING
                | OP_CLEAR_STATEID,
        .op_name = "OP_PUTFH",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_PUTPUBFH] = {
        .op_func = (nfsd4op_func)nfsd4_putrootfh,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING
                | OP_CLEAR_STATEID,
        .op_name = "OP_PUTPUBFH",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_PUTROOTFH] = {
        .op_func = (nfsd4op_func)nfsd4_putrootfh,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING
                | OP_CLEAR_STATEID,
        .op_name = "OP_PUTROOTFH",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_READ] = {
        .op_func = (nfsd4op_func)nfsd4_read,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_READ",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_read_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_readstateid,
    },
    [OP_READDIR] = {
        .op_func = (nfsd4op_func)nfsd4_readdir,
        .op_flags = OP_MODIFIES_SOMETHING,
        .op_name = "OP_READDIR",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_readdir_rsize,
    },
    [OP_READLINK] = {
        .op_func = (nfsd4op_func)nfsd4_readlink,
        .op_name = "OP_READLINK",
    },
    [OP_REMOVE] = {
        .op_func = (nfsd4op_func)nfsd4_remove,
        .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_name = "OP_REMOVE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_remove_rsize,
    },
    [OP_RENAME] = {
        .op_func = (nfsd4op_func)nfsd4_rename,
        .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_name = "OP_RENAME",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_rename_rsize,
    },
    [OP_RENEW] = {
        .op_func = (nfsd4op_func)nfsd4_renew,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_RENEW",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,

    },
    [OP_RESTOREFH] = {
        .op_func = (nfsd4op_func)nfsd4_restorefh,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_IS_PUTFH_LIKE | OP_MODIFIES_SOMETHING,
        .op_name = "OP_RESTOREFH",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_SAVEFH] = {
        .op_func = (nfsd4op_func)nfsd4_savefh,
        .op_flags = OP_HANDLES_WRONGSEC | OP_MODIFIES_SOMETHING,
        .op_name = "OP_SAVEFH",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_SECINFO] = {
        .op_func = (nfsd4op_func)nfsd4_secinfo,
        .op_flags = OP_HANDLES_WRONGSEC,
        .op_name = "OP_SECINFO",
    },
    [OP_SETATTR] = {
        .op_func = (nfsd4op_func)nfsd4_setattr,
        .op_name = "OP_SETATTR",
        .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_setattr_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_setattrstateid,
    },
    [OP_SETCLIENTID] = {
        .op_func = (nfsd4op_func)nfsd4_setclientid,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_name = "OP_SETCLIENTID",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_setclientid_rsize,
    },
    [OP_SETCLIENTID_CONFIRM] = {
        .op_func = (nfsd4op_func)nfsd4_setclientid_confirm,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_name = "OP_SETCLIENTID_CONFIRM",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_VERIFY] = {
        .op_func = (nfsd4op_func)nfsd4_verify,
        .op_name = "OP_VERIFY",
    },
    [OP_WRITE] = {
        .op_func = (nfsd4op_func)nfsd4_write,
        .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
        .op_name = "OP_WRITE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_write_rsize,
        .op_get_currentstateid = (stateid_getter)nfsd4_get_writestateid,
    },
    [OP_RELEASE_LOCKOWNER] = {
        .op_func = (nfsd4op_func)nfsd4_release_lockowner,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_RELEASE_LOCKOWNER",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },

    /* NFSv4.1 operations */
    [OP_EXCHANGE_ID] = {
        .op_func = (nfsd4op_func)nfsd4_exchange_id,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_EXCHANGE_ID",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_exchange_id_rsize,
    },
    [OP_BIND_CONN_TO_SESSION] = {
        .op_func = (nfsd4op_func)nfsd4_bind_conn_to_session,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_BIND_CONN_TO_SESSION",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_bind_conn_to_session_rsize,
    },
    [OP_CREATE_SESSION] = {
        .op_func = (nfsd4op_func)nfsd4_create_session,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_CREATE_SESSION",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_create_session_rsize,
    },
    [OP_DESTROY_SESSION] = {
        .op_func = (nfsd4op_func)nfsd4_destroy_session,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_DESTROY_SESSION",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_SEQUENCE] = {
        .op_func = (nfsd4op_func)nfsd4_sequence,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP,
        .op_name = "OP_SEQUENCE",
    },
    [OP_DESTROY_CLIENTID] = {
        .op_func = (nfsd4op_func)nfsd4_destroy_clientid,
        .op_flags = ALLOWED_WITHOUT_FH | ALLOWED_AS_FIRST_OP
                | OP_MODIFIES_SOMETHING,
        .op_name = "OP_DESTROY_CLIENTID",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_RECLAIM_COMPLETE] = {
        .op_func = (nfsd4op_func)nfsd4_reclaim_complete,
        .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
        .op_name = "OP_RECLAIM_COMPLETE",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
    [OP_SECINFO_NO_NAME] = {
        .op_func = (nfsd4op_func)nfsd4_secinfo_no_name,
        .op_flags = OP_HANDLES_WRONGSEC,
        .op_name = "OP_SECINFO_NO_NAME",
    },
    [OP_TEST_STATEID] = {
        .op_func = (nfsd4op_func)nfsd4_test_stateid,
        .op_flags = ALLOWED_WITHOUT_FH,
        .op_name = "OP_TEST_STATEID",
    },
    [OP_FREE_STATEID] = {
        .op_func = (nfsd4op_func)nfsd4_free_stateid,
        .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
        .op_name = "OP_FREE_STATEID",
        .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
    },
};

#ifdef NFSD_DEBUG
static const char *nfsd4_op_name(unsigned opnum)
{
    if (opnum < ARRAY_SIZE(nfsd4_ops))
        return nfsd4_ops[opnum].op_name;
    return "unknown_operation";
}
#endif

#define nfsd4_voidres           nfsd4_voidargs
struct nfsd4_voidargs { int dummy; };

static struct svc_procedure     nfsd_procedures4[2] = {
    [NFSPROC4_NULL] = {
        .pc_func = (svc_procfunc) nfsd4_proc_null,
        .pc_encode = (kxdrproc_t) nfs4svc_encode_voidres,
        .pc_argsize = sizeof(struct nfsd4_voidargs),
        .pc_ressize = sizeof(struct nfsd4_voidres),
        .pc_cachetype = RC_NOCACHE,
        .pc_xdrressize = 1,
    },
    [NFSPROC4_COMPOUND] = {
        .pc_func = (svc_procfunc) nfsd4_proc_compound,
        .pc_decode = (kxdrproc_t) nfs4svc_decode_compoundargs,
        .pc_encode = (kxdrproc_t) nfs4svc_encode_compoundres,
        .pc_argsize = sizeof(struct nfsd4_compoundargs),
        .pc_ressize = sizeof(struct nfsd4_compoundres),
        .pc_release = nfsd4_release_compoundargs,
        .pc_cachetype = RC_NOCACHE,
        .pc_xdrressize = NFSD_BUFSIZE/4,
    },
};

struct svc_version  nfsd_version4 = {
        .vs_vers    = 4,
        .vs_nproc   = 2,
        .vs_proc    = nfsd_procedures4,
        .vs_dispatch    = nfsd_dispatch,
        .vs_xdrsize = NFS4_SVC_XDRSIZE,
};

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