/*
 *  Server-side procedures for NFSv4.
 *
 *  Copyright (c) 2002 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Kendrick Smith <kmsmith@umich.edu>
 *  Andy Adamson   <andros@umich.edu>
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions
 *  are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the University nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <linux/file.h>
#include <linux/falloc.h>
#include <linux/slab.h>

#include "idmap.h"
#include "cache.h"
#include "xdr4.h"
#include "vfs.h"
#include "current_stateid.h"
#include "netns.h"
#include "acl.h"
#include "pnfs.h"
#include "trace.h"

#ifdef CONFIG_NFSD_V4_SECURITY_LABEL
#include <linux/security.h>

static inline void
nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval)
{
        struct inode *inode = d_inode(resfh->fh_dentry);
        int status;

        mutex_lock(&inode->i_mutex);
        status = security_inode_setsecctx(resfh->fh_dentry,
                label->data, label->len);
        mutex_unlock(&inode->i_mutex);

        if (status)
                /*
                 * XXX: We should really fail the whole open, but we may
                 * already have created a new file, so it may be too
                 * late.  For now this seems the least of evils:
                 */
                bmval[2] &= ~FATTR4_WORD2_SECURITY_LABEL;

        return;
}
#else
static inline void
nfsd4_security_inode_setsecctx(struct svc_fh *resfh, struct xdr_netobj *label, u32 *bmval)
{ }
#endif

#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(d_inode(dentry)))
                        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)
                exp_get(src->fh_export);
        *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 = d_inode(fh->fh_dentry)->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 void nfsd4_set_open_owner_reply_cache(struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh *resfh)
{
        if (nfsd4_has_session(cstate))
                return;
        fh_copy_shallow(&open->op_openowner->oo_owner.so_replay.rp_openfh,
                        &resfh->fh_handle);
}

static __be32
do_open_lookup(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open, struct svc_fh **resfh)
{
        struct svc_fh *current_fh = &cstate->current_fh;
        int accmode;
        __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);

                if (!status && open->op_label.len)
                        nfsd4_security_inode_setsecctx(*resfh, &open->op_label, open->op_bmval);

                /*
                 * 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
                /*
                 * Note this may exit with the parent still locked.
                 * We will hold the lock until nfsd4_open's final
                 * lookup, to prevent renames or unlinks until we've had
                 * a chance to an acquire a delegation if appropriate.
                 */
                status = nfsd_lookup(rqstp, current_fh,
                                     open->op_fname.data, open->op_fname.len, *resfh);
        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);

        nfsd4_set_open_owner_reply_cache(cstate, open, *resfh);
        accmode = NFSD_MAY_NOP;
        if (open->op_created ||
                        open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
                accmode |= NFSD_MAY_OWNER_OVERRIDE;
        status = do_open_permission(rqstp, *resfh, open, accmode);
        set_change_info(&open->op_cinfo, current_fh);
out:
        return status;
}

static __be32
do_open_fhandle(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_open *open)
{
        struct svc_fh *current_fh = &cstate->current_fh;
        __be32 status;
        int accmode = 0;

        /* 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));

        nfsd4_set_open_owner_reply_cache(cstate, open, current_fh);

        open->op_truncate = (open->op_iattr.ia_valid & ATTR_SIZE) &&
                (open->op_iattr.ia_size == 0);
        /*
         * In the delegation case, the client is telling us about an
         * open that it *already* performed locally, some time ago.  We
         * should let it succeed now if possible.
         *
         * In the case of a CLAIM_FH open, on the other hand, the client
         * may be counting on us to enforce permissions (the Linux 4.1
         * client uses this for normal opens, for example).
         */
        if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEG_CUR_FH)
                accmode = NFSD_MAY_OWNER_OVERRIDE;

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

        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 svc_fh *resfh = NULL;
        struct nfsd4_compoundres *resp;
        struct net *net = SVC_NET(rqstp);
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);

        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);

        /* check seqid for replay. set nfs4_owner */
        resp = rqstp->rq_resp;
        status = nfsd4_process_open1(&resp->cstate, open, nn);
        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;
        if (open->op_xdr_error) {
                status = open->op_xdr_error;
                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(net) && open->op_claim_type != NFS4_OPEN_CLAIM_PREVIOUS)
                goto out;
        status = nfserr_no_grace;
        if (!locks_in_grace(net) && 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, open, &resfh);
                        if (status)
                                goto out;
                        break;
                case NFS4_OPEN_CLAIM_PREVIOUS:
                        status = nfs4_check_open_reclaim(&open->op_clientid,
                                                         cstate, nn);
                        if (status)
                                goto out;
                        open->op_openowner->oo_flags |= NFS4_OO_CONFIRMED;
                case NFS4_OPEN_CLAIM_FH:
                case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
                        status = do_open_fhandle(rqstp, cstate, open);
                        if (status)
                                goto out;
                        resfh = &cstate->current_fh;
                        break;
                case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
                case NFS4_OPEN_CLAIM_DELEGATE_PREV:
                        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, resfh, open);
        WARN(status && open->op_created,
             "nfsd4_process_open2 failed to open newly-created file! status=%u\n",
             be32_to_cpu(status));
out:
        if (resfh && resfh != &cstate->current_fh) {
                fh_dup2(&cstate->current_fh, resfh);
                fh_put(resfh);
                kfree(resfh);
        }
        nfsd4_cleanup_open_state(cstate, open);
        nfsd4_bump_seqid(cstate, status);
        return status;
}

/*
 * OPEN is the only seqid-mutating operation whose decoding can fail
 * with a seqid-mutating error (specifically, decoding of user names in
 * the attributes).  Therefore we have to do some processing to look up
 * the stateowner so that we can bump the seqid.
 */
static __be32 nfsd4_open_omfg(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate, struct nfsd4_op *op)
{
        struct nfsd4_open *open = (struct nfsd4_open *)&op->u;

        if (!seqid_mutating_err(ntohl(op->status)))
                return op->status;
        if (nfsd4_has_session(cstate))
                return op->status;
        open->op_xdr_error = op->status;
        return nfsd4_open(rqstp, cstate, open);
}

/*
 * 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, struct net *net)
{
        __be32 verf[2];
        struct nfsd_net *nn = net_generic(net, nfsd_net_id);

        /*
         * This is opaque to client, so no need to byte-swap. Use
         * __force to keep sparse happy
         */
        verf[0] = (__force __be32)nn->nfssvc_boot.tv_sec;
        verf[1] = (__force __be32)nn->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, SVC_NET(rqstp));
        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:
                status = nfsd_symlink(rqstp, &cstate->current_fh,
                                      create->cr_name, create->cr_namelen,
                                      create->cr_data, &resfh);
                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_label.len)
                nfsd4_security_inode_setsecctx(&resfh, &create->cr_label, create->cr_bmval);

        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;

        /*
         * If we do a zero copy read, then a client will see read data
         * that reflects the state of the file *after* performing the
         * following compound.
         *
         * To ensure proper ordering, we therefore turn off zero copy if
         * the client wants us to do more in this compound:
         */
        if (!nfsd4_last_compound_op(rqstp))
                clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);

        /* 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;
        }
        status = nfs_ok;
out:
        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);
        if (status)
                return status;
        set_change_info(&rename->rn_sinfo, &cstate->current_fh);
        set_change_info(&rename->rn_tinfo, &cstate->save_fh);
        return nfs_ok;
}

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 (d_really_is_negative(dentry)) {
                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;
        }

        sin->sin_exp = exp_get(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) {
                status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
                        &setattr->sa_stateid, WR_STATE, NULL);
                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;
        if (setattr->sa_label.len)
                status = nfsd4_set_nfs4_label(rqstp, &cstate->current_fh,
                                &setattr->sa_label);
        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 int fill_in_write_vector(struct kvec *vec, struct nfsd4_write *write)
{
        int i = 1;
        int buflen = write->wr_buflen;

        vec[0].iov_base = write->wr_head.iov_base;
        vec[0].iov_len = min_t(int, buflen, write->wr_head.iov_len);
        buflen -= vec[0].iov_len;

        while (buflen) {
                vec[i].iov_base = page_address(write->wr_pagelist[i - 1]);
                vec[i].iov_len = min_t(int, PAGE_SIZE, buflen);
                buflen -= vec[i].iov_len;
                i++;
        }
        return i;
}

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;
        int nvecs;

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

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

        status = nfs4_preprocess_stateid_op(SVC_NET(rqstp),
                                        cstate, stateid, WR_STATE, &filp);
        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, SVC_NET(rqstp));

        nvecs = fill_in_write_vector(rqstp->rq_vec, write);
        WARN_ON_ONCE(nvecs > ARRAY_SIZE(rqstp->rq_vec));

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

        write->wr_bytes_written = cnt;

        return status;
}

static __be32
nfsd4_fallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                struct nfsd4_fallocate *fallocate, int flags)
{
        __be32 status = nfserr_notsupp;
        struct file *file;

        status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
                                            &fallocate->falloc_stateid,
                                            WR_STATE, &file);
        if (status != nfs_ok) {
                dprintk("NFSD: nfsd4_fallocate: couldn't process stateid!\n");
                return status;
        }
        if (!file)
                return nfserr_bad_stateid;

        status = nfsd4_vfs_fallocate(rqstp, &cstate->current_fh, file,
                                     fallocate->falloc_offset,
                                     fallocate->falloc_length,
                                     flags);
        fput(file);
        return status;
}

static __be32
nfsd4_allocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
               struct nfsd4_fallocate *fallocate)
{
        return nfsd4_fallocate(rqstp, cstate, fallocate, 0);
}

static __be32
nfsd4_deallocate(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                 struct nfsd4_fallocate *fallocate)
{
        return nfsd4_fallocate(rqstp, cstate, fallocate,
                               FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE);
}

static __be32
nfsd4_seek(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
                struct nfsd4_seek *seek)
{
        int whence;
        __be32 status;
        struct file *file;

        status = nfs4_preprocess_stateid_op(SVC_NET(rqstp), cstate,
                                            &seek->seek_stateid,
                                            RD_STATE, &file);
        if (status) {
                dprintk("NFSD: nfsd4_seek: couldn't process stateid!\n");
                return status;
        }
        if (!file)
                return nfserr_bad_stateid;

        switch (seek->seek_whence) {
        case NFS4_CONTENT_DATA:
                whence = SEEK_DATA;
                break;
        case NFS4_CONTENT_HOLE:
                whence = SEEK_HOLE;
                break;
        default:
                status = nfserr_union_notsupp;
                goto out;
        }

        /*
         * Note:  This call does change file->f_pos, but nothing in NFSD
         *        should ever file->f_pos.
         */
        seek->seek_pos = vfs_llseek(file, seek->seek_offset, whence);
        if (seek->seek_pos < 0)
                status = nfserrno(seek->seek_pos);
        else if (seek->seek_pos >= i_size_read(file_inode(file)))
                seek->seek_eof = true;

out:
        fput(file);
        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;

        p = buf;
        status = nfsd4_encode_fattr_to_buf(&p, count, &cstate->current_fh,
                                    cstate->current_fh.fh_export,
                                    cstate->current_fh.fh_dentry,
                                    verify->ve_bmval,
                                    rqstp, 0);
        /*
         * If nfsd4_encode_fattr() ran out of space, assume that's because
         * the attributes are longer (hence different) than those given:
         */
        if (status == nfserr_resource)
                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;
}

#ifdef CONFIG_NFSD_PNFS
static const struct nfsd4_layout_ops *
nfsd4_layout_verify(struct svc_export *exp, unsigned int layout_type)
{
        if (!exp->ex_layout_type) {
                dprintk("%s: export does not support pNFS\n", __func__);
                return NULL;
        }

        if (exp->ex_layout_type != layout_type) {
                dprintk("%s: layout type %d not supported\n",
                        __func__, layout_type);
                return NULL;
        }

        return nfsd4_layout_ops[layout_type];
}

static __be32
nfsd4_getdeviceinfo(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *cstate,
                struct nfsd4_getdeviceinfo *gdp)
{
        const struct nfsd4_layout_ops *ops;
        struct nfsd4_deviceid_map *map;
        struct svc_export *exp;
        __be32 nfserr;

        dprintk("%s: layout_type %u dev_id [0x%llx:0x%x] maxcnt %u\n",
               __func__,
               gdp->gd_layout_type,
               gdp->gd_devid.fsid_idx, gdp->gd_devid.generation,
               gdp->gd_maxcount);

        map = nfsd4_find_devid_map(gdp->gd_devid.fsid_idx);
        if (!map) {
                dprintk("%s: couldn't find device ID to export mapping!\n",
                        __func__);
                return nfserr_noent;
        }

        exp = rqst_exp_find(rqstp, map->fsid_type, map->fsid);
        if (IS_ERR(exp)) {
                dprintk("%s: could not find device id\n", __func__);
                return nfserr_noent;
        }

        nfserr = nfserr_layoutunavailable;
        ops = nfsd4_layout_verify(exp, gdp->gd_layout_type);
        if (!ops)
                goto out;

        nfserr = nfs_ok;
        if (gdp->gd_maxcount != 0)
                nfserr = ops->proc_getdeviceinfo(exp->ex_path.mnt->mnt_sb, gdp);

        gdp->gd_notify_types &= ops->notify_types;
out:
        exp_put(exp);
        return nfserr;
}

static __be32
nfsd4_layoutget(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *cstate,
                struct nfsd4_layoutget *lgp)
{
        struct svc_fh *current_fh = &cstate->current_fh;
        const struct nfsd4_layout_ops *ops;
        struct nfs4_layout_stateid *ls;
        __be32 nfserr;
        int accmode;

        switch (lgp->lg_seg.iomode) {
        case IOMODE_READ:
                accmode = NFSD_MAY_READ;
                break;
        case IOMODE_RW:
                accmode = NFSD_MAY_READ | NFSD_MAY_WRITE;
                break;
        default:
                dprintk("%s: invalid iomode %d\n",
                        __func__, lgp->lg_seg.iomode);
                nfserr = nfserr_badiomode;
                goto out;
        }

        nfserr = fh_verify(rqstp, current_fh, 0, accmode);
        if (nfserr)
                goto out;

        nfserr = nfserr_layoutunavailable;
        ops = nfsd4_layout_verify(current_fh->fh_export, lgp->lg_layout_type);
        if (!ops)
                goto out;

        /*
         * Verify minlength and range as per RFC5661:
         *  o  If loga_length is less than loga_minlength,
         *     the metadata server MUST return NFS4ERR_INVAL.
         *  o  If the sum of loga_offset and loga_minlength exceeds
         *     NFS4_UINT64_MAX, and loga_minlength is not
         *     NFS4_UINT64_MAX, the error NFS4ERR_INVAL MUST result.
         *  o  If the sum of loga_offset and loga_length exceeds
         *     NFS4_UINT64_MAX, and loga_length is not NFS4_UINT64_MAX,
         *     the error NFS4ERR_INVAL MUST result.
         */
        nfserr = nfserr_inval;
        if (lgp->lg_seg.length < lgp->lg_minlength ||
            (lgp->lg_minlength != NFS4_MAX_UINT64 &&
             lgp->lg_minlength > NFS4_MAX_UINT64 - lgp->lg_seg.offset) ||
            (lgp->lg_seg.length != NFS4_MAX_UINT64 &&
             lgp->lg_seg.length > NFS4_MAX_UINT64 - lgp->lg_seg.offset))
                goto out;
        if (lgp->lg_seg.length == 0)
                goto out;

        nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lgp->lg_sid,
                                                true, lgp->lg_layout_type, &ls);
        if (nfserr) {
                trace_layout_get_lookup_fail(&lgp->lg_sid);
                goto out;
        }

        nfserr = nfserr_recallconflict;
        if (atomic_read(&ls->ls_stid.sc_file->fi_lo_recalls))
                goto out_put_stid;

        nfserr = ops->proc_layoutget(d_inode(current_fh->fh_dentry),
                                     current_fh, lgp);
        if (nfserr)
                goto out_put_stid;

        nfserr = nfsd4_insert_layout(lgp, ls);

out_put_stid:
        nfs4_put_stid(&ls->ls_stid);
out:
        return nfserr;
}

static __be32
nfsd4_layoutcommit(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *cstate,
                struct nfsd4_layoutcommit *lcp)
{
        const struct nfsd4_layout_seg *seg = &lcp->lc_seg;
        struct svc_fh *current_fh = &cstate->current_fh;
        const struct nfsd4_layout_ops *ops;
        loff_t new_size = lcp->lc_last_wr + 1;
        struct inode *inode;
        struct nfs4_layout_stateid *ls;
        __be32 nfserr;

        nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_WRITE);
        if (nfserr)
                goto out;

        nfserr = nfserr_layoutunavailable;
        ops = nfsd4_layout_verify(current_fh->fh_export, lcp->lc_layout_type);
        if (!ops)
                goto out;
        inode = d_inode(current_fh->fh_dentry);

        nfserr = nfserr_inval;
        if (new_size <= seg->offset) {
                dprintk("pnfsd: last write before layout segment\n");
                goto out;
        }
        if (new_size > seg->offset + seg->length) {
                dprintk("pnfsd: last write beyond layout segment\n");
                goto out;
        }
        if (!lcp->lc_newoffset && new_size > i_size_read(inode)) {
                dprintk("pnfsd: layoutcommit beyond EOF\n");
                goto out;
        }

        nfserr = nfsd4_preprocess_layout_stateid(rqstp, cstate, &lcp->lc_sid,
                                                false, lcp->lc_layout_type,
                                                &ls);
        if (nfserr) {
                trace_layout_commit_lookup_fail(&lcp->lc_sid);
                /* fixup error code as per RFC5661 */
                if (nfserr == nfserr_bad_stateid)
                        nfserr = nfserr_badlayout;
                goto out;
        }

        nfserr = ops->proc_layoutcommit(inode, lcp);
        if (nfserr)
                goto out_put_stid;

        if (new_size > i_size_read(inode)) {
                lcp->lc_size_chg = 1;
                lcp->lc_newsize = new_size;
        } else {
                lcp->lc_size_chg = 0;
        }

out_put_stid:
        nfs4_put_stid(&ls->ls_stid);
out:
        return nfserr;
}

static __be32
nfsd4_layoutreturn(struct svc_rqst *rqstp,
                struct nfsd4_compound_state *cstate,
                struct nfsd4_layoutreturn *lrp)
{
        struct svc_fh *current_fh = &cstate->current_fh;
        __be32 nfserr;

        nfserr = fh_verify(rqstp, current_fh, 0, NFSD_MAY_NOP);
        if (nfserr)
                goto out;

        nfserr = nfserr_layoutunavailable;
        if (!nfsd4_layout_verify(current_fh->fh_export, lrp->lr_layout_type))
                goto out;

        switch (lrp->lr_seg.iomode) {
        case IOMODE_READ:
        case IOMODE_RW:
        case IOMODE_ANY:
                break;
        default:
                dprintk("%s: invalid iomode %d\n", __func__,
                        lrp->lr_seg.iomode);
                nfserr = nfserr_inval;
                goto out;
        }

        switch (lrp->lr_return_type) {
        case RETURN_FILE:
                nfserr = nfsd4_return_file_layouts(rqstp, cstate, lrp);
                break;
        case RETURN_FSID:
        case RETURN_ALL:
                nfserr = nfsd4_return_client_layouts(rqstp, cstate, lrp);
                break;
        default:
                dprintk("%s: invalid return_type %d\n", __func__,
                        lrp->lr_return_type);
                nfserr = nfserr_inval;
                break;
        }
out:
        return nfserr;
}
#endif /* CONFIG_NFSD_PNFS */

/*
 * 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[];

static const char *nfsd4_op_name(unsigned opnum);

/*
 * 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)
{
        if (op->opnum == OP_ILLEGAL)
                return false;
        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;
        if (next->opnum == OP_ILLEGAL)
                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);
}

static void svcxdr_init_encode(struct svc_rqst *rqstp,
                               struct nfsd4_compoundres *resp)
{
        struct xdr_stream *xdr = &resp->xdr;
        struct xdr_buf *buf = &rqstp->rq_res;
        struct kvec *head = buf->head;

        xdr->buf = buf;
        xdr->iov = head;
        xdr->p   = head->iov_base + head->iov_len;
        xdr->end = head->iov_base + PAGE_SIZE - rqstp->rq_auth_slack;
        /* Tail and page_len should be zero at this point: */
        buf->len = buf->head[0].iov_len;
        xdr->scratch.iov_len = 0;
        xdr->page_ptr = buf->pages - 1;
        buf->buflen = PAGE_SIZE * (1 + rqstp->rq_page_end - buf->pages)
                - rqstp->rq_auth_slack;
}

/*
 * 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;
        struct svc_fh *current_fh = &cstate->current_fh;
        struct svc_fh *save_fh = &cstate->save_fh;
        __be32          status;

        svcxdr_init_encode(rqstp, resp);
        resp->tagp = resp->xdr.p;
        /* reserve space for: taglen, tag, and opcnt */
        xdr_reserve_space(&resp->xdr, 8 + args->taglen);
        resp->taglen = args->taglen;
        resp->tag = args->tag;
        resp->rqstp = rqstp;
        cstate->minorversion = args->minorversion;
        fh_init(current_fh, NFS4_FHSIZE);
        fh_init(save_fh, NFS4_FHSIZE);
        /*
         * Don't use the deferral mechanism for NFSv4; compounds make it
         * too hard to avoid non-idempotency problems.
         */
        clear_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);

        /*
         * According to RFC3010, this takes precedence over all other errors.
         */
        status = nfserr_minor_vers_mismatch;
        if (nfsd_minorversion(args->minorversion, NFSD_TEST) <= 0)
                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) {
                        if (op->opnum == OP_OPEN)
                                op->status = nfsd4_open_omfg(rqstp, cstate, op);
                        goto encode_op;
                }

                opdesc = OPDESC(op);

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

                fh_clear_wcc(current_fh);

                /* If op is non-idempotent */
                if (opdesc->op_flags & OP_MODIFIES_SOMETHING) {
                        /*
                         * Don't execute this op if we couldn't encode a
                         * succesful reply:
                         */
                        u32 plen = opdesc->op_rsize_bop(rqstp, op);
                        /*
                         * Plus if there's another operation, make sure
                         * we'll have space to at least encode an error:
                         */
                        if (resp->opcnt < args->opcnt)
                                plen += COMPOUND_ERR_SLACK_SPACE;
                        op->status = nfsd4_check_resp_size(resp, plen);
                }

                if (op->status)
                        goto encode_op;

                if (opdesc->op_get_currentstateid)
                        opdesc->op_get_currentstateid(cstate, &op->u);
                op->status = opdesc->op_func(rqstp, cstate, &op->u);

                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(current_fh->fh_export, rqstp);
                }

encode_op:
                /* Only from SEQUENCE */
                if (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->xdr, 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));

                nfsd4_cstate_clear_replay(cstate);
                /* 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);
        }

        cstate->status = status;
        fh_put(current_fh);
        fh_put(save_fh);
        BUG_ON(cstate->replay_owner);
out:
        /* Reset deferral mechanism for RPC deferrals */
        set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
        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)

/* We'll fall back on returning no lockowner if run out of space: */
#define op_encode_lockowner_maxsz       (0)
#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);
}

/*
 * Note since this is an idempotent operation we won't insist on failing
 * the op prematurely if the estimate is too large.  We may turn off splice
 * reads unnecessarily.
 */
static inline u32 nfsd4_getattr_rsize(struct svc_rqst *rqstp,
                                      struct nfsd4_op *op)
{
        u32 *bmap = op->u.getattr.ga_bmval;
        u32 bmap0 = bmap[0], bmap1 = bmap[1], bmap2 = bmap[2];
        u32 ret = 0;

        if (bmap0 & FATTR4_WORD0_ACL)
                return svc_max_payload(rqstp);
        if (bmap0 & FATTR4_WORD0_FS_LOCATIONS)
                return svc_max_payload(rqstp);

        if (bmap1 & FATTR4_WORD1_OWNER) {
                ret += IDMAP_NAMESZ + 4;
                bmap1 &= ~FATTR4_WORD1_OWNER;
        }
        if (bmap1 & FATTR4_WORD1_OWNER_GROUP) {
                ret += IDMAP_NAMESZ + 4;
                bmap1 &= ~FATTR4_WORD1_OWNER_GROUP;
        }
        if (bmap0 & FATTR4_WORD0_FILEHANDLE) {
                ret += NFS4_FHSIZE + 4;
                bmap0 &= ~FATTR4_WORD0_FILEHANDLE;
        }
        if (bmap2 & FATTR4_WORD2_SECURITY_LABEL) {
                ret += NFS4_MAXLABELLEN + 12;
                bmap2 &= ~FATTR4_WORD2_SECURITY_LABEL;
        }
        /*
         * Largest of remaining attributes are 16 bytes (e.g.,
         * supported_attributes)
         */
        ret += 16 * (hweight32(bmap0) + hweight32(bmap1) + hweight32(bmap2));
        /* bitmask, length */
        ret += 20;
        return ret;
}

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 = min(op->u.read.rd_length, maxcount);

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

static inline u32 nfsd4_readdir_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        u32 maxcount = 0, rlen = 0;

        maxcount = svc_max_payload(rqstp);
        rlen = min(op->u.readdir.rd_maxcount, maxcount);

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

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_sequence_rsize(struct svc_rqst *rqstp,
                                       struct nfsd4_op *op)
{
        return (op_encode_hdr_size
                + XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN) + 5) * 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 + XDR_QUADLEN(NFS4_VERIFIER_SIZE)) *
                                                                sizeof(__be32);
}

static inline u32 nfsd4_write_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        return (op_encode_hdr_size + 2 + 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 + /* eir_flags, spr_how */\
                4 + /* spo_must_enforce & _allow with bitmap */\
                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);
}

#ifdef CONFIG_NFSD_PNFS
/*
 * At this stage we don't really know what layout driver will handle the request,
 * so we need to define an arbitrary upper bound here.
 */
#define MAX_LAYOUT_SIZE         128
static inline u32 nfsd4_layoutget_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        return (op_encode_hdr_size +
                1 /* logr_return_on_close */ +
                op_encode_stateid_maxsz +
                1 /* nr of layouts */ +
                MAX_LAYOUT_SIZE) * sizeof(__be32);
}

static inline u32 nfsd4_layoutcommit_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        return (op_encode_hdr_size +
                1 /* locr_newsize */ +
                2 /* ns_size */) * sizeof(__be32);
}

static inline u32 nfsd4_layoutreturn_rsize(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        return (op_encode_hdr_size +
                1 /* lrs_stateid */ +
                op_encode_stateid_maxsz) * sizeof(__be32);
}
#endif /* CONFIG_NFSD_PNFS */

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_rsize_bop = nfsd4_getattr_rsize,
                .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_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_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_CLEAR_STATEID,
                .op_name = "OP_PUTROOTFH",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
        },
        [OP_READ] = {
                .op_func = (nfsd4op_func)nfsd4_read,
                .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_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_BACKCHANNEL_CTL] = {
                .op_func = (nfsd4op_func)nfsd4_backchannel_ctl,
                .op_flags = ALLOWED_WITHOUT_FH | OP_MODIFIES_SOMETHING,
                .op_name = "OP_BACKCHANNEL_CTL",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_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_rsize_bop = (nfsd4op_rsize)nfsd4_sequence_rsize,
        },
        [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_get_currentstateid = (stateid_getter)nfsd4_get_freestateid,
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
        },
#ifdef CONFIG_NFSD_PNFS
        [OP_GETDEVICEINFO] = {
                .op_func = (nfsd4op_func)nfsd4_getdeviceinfo,
                .op_flags = ALLOWED_WITHOUT_FH,
                .op_name = "OP_GETDEVICEINFO",
        },
        [OP_LAYOUTGET] = {
                .op_func = (nfsd4op_func)nfsd4_layoutget,
                .op_flags = OP_MODIFIES_SOMETHING,
                .op_name = "OP_LAYOUTGET",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_layoutget_rsize,
        },
        [OP_LAYOUTCOMMIT] = {
                .op_func = (nfsd4op_func)nfsd4_layoutcommit,
                .op_flags = OP_MODIFIES_SOMETHING,
                .op_name = "OP_LAYOUTCOMMIT",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_layoutcommit_rsize,
        },
        [OP_LAYOUTRETURN] = {
                .op_func = (nfsd4op_func)nfsd4_layoutreturn,
                .op_flags = OP_MODIFIES_SOMETHING,
                .op_name = "OP_LAYOUTRETURN",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_layoutreturn_rsize,
        },
#endif /* CONFIG_NFSD_PNFS */

        /* NFSv4.2 operations */
        [OP_ALLOCATE] = {
                .op_func = (nfsd4op_func)nfsd4_allocate,
                .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
                .op_name = "OP_ALLOCATE",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
        },
        [OP_DEALLOCATE] = {
                .op_func = (nfsd4op_func)nfsd4_deallocate,
                .op_flags = OP_MODIFIES_SOMETHING | OP_CACHEME,
                .op_name = "OP_DEALLOCATE",
                .op_rsize_bop = (nfsd4op_rsize)nfsd4_only_status_rsize,
        },
        [OP_SEEK] = {
                .op_func = (nfsd4op_func)nfsd4_seek,
                .op_name = "OP_SEEK",
        },
};

int nfsd4_max_reply(struct svc_rqst *rqstp, struct nfsd4_op *op)
{
        struct nfsd4_operation *opdesc;
        nfsd4op_rsize estimator;

        if (op->opnum == OP_ILLEGAL)
                return op_encode_hdr_size * sizeof(__be32);
        opdesc = OPDESC(op);
        estimator = opdesc->op_rsize_bop;
        return estimator ? estimator(rqstp, op) : PAGE_SIZE;
}

void warn_on_nonidempotent_op(struct nfsd4_op *op)
{
        if (OPDESC(op)->op_flags & OP_MODIFIES_SOMETHING) {
                pr_err("unable to encode reply to nonidempotent op %d (%s)\n",
                        op->opnum, nfsd4_op_name(op->opnum));
                WARN_ON_ONCE(1);
        }
}

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

#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,
                .vs_rpcb_optnl  = 1,
};

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