/*      $NetBSD: nfs_serv.c,v 1.185 2026/06/18 19:58:17 christos Exp $  */

/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * 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 BY THE REGENTS AND CONTRIBUTORS ``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.
 *
 *      @(#)nfs_serv.c  8.8 (Berkeley) 7/31/95
 */

/*
 * nfs version 2 and 3 server calls to vnode ops
 * - these routines generally have 3 phases
 *   1 - break down and validate rpc request in mbuf list
 *   2 - do the vnode ops for the request
 *       (surprisingly ?? many are very similar to syscalls in vfs_syscalls.c)
 *   3 - build the rpc reply in an mbuf list
 *   nb:
 *      - do not mix the phases, since the nfsm_?? macros can return failures
 *        on a bad rpc or similar and do not do any vrele() or vput()'s
 *
 *      - the nfsm_reply() macro generates an nfs rpc reply with the nfs
 *      error number iff error != 0 whereas
 *      returning an error from the server function implies a fatal error
 *      such as a badly constructed rpc request that should be dropped without
 *      a reply.
 *      For Version 3, nfsm_reply() does not return for the error case, since
 *      most version 3 rpcs return more than the status for error cases.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nfs_serv.c,v 1.185 2026/06/18 19:58:17 christos Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/fstrans.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/mbuf.h>
#include <sys/dirent.h>
#include <sys/stat.h>
#include <sys/kernel.h>
#include <sys/hash.h>
#include <sys/kauth.h>
#include <sys/module.h>
#include <sys/syscall.h>
#include <sys/syscallargs.h>
#include <sys/syscallvar.h>

#include <uvm/uvm_extern.h>
#include <uvm/uvm_loan.h>
#include <uvm/uvm_page.h>

#include <nfs/nfsproto.h>
#include <nfs/rpcv2.h>
#include <nfs/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfs/nfsm_subs.h>
#include <nfs/nfs_var.h>

MODULE(MODULE_CLASS_MISC, nfsserver, "nfs");

/* Global vars */
extern u_int32_t nfs_xdrneg1;
extern u_int32_t nfs_false, nfs_true;
extern const enum vtype nv3tov_type[8];
extern struct nfsstats nfsstats;
extern const nfstype nfsv2_type[9];
extern const nfstype nfsv3_type[9];
int nfsrvw_procrastinate = NFS_GATHERDELAY * 1000;
bool nfsd_use_loan = true;      /* use page-loan for READ OP */

#define nqsrv_getl(vp, rw)      /* nothing */

static const struct syscall_package nfsserver_syscalls[] = {
        { SYS_nfssvc, 0, (sy_call_t *)sys_nfssvc },
        { 0, 0, NULL },
};

static int
nfsserver_modcmd(modcmd_t cmd, void *arg)
{
        extern struct vfs_hooks nfs_export_hooks;       /* XXX */
        int error;

        switch (cmd) {
        case MODULE_CMD_INIT:
                error = syscall_establish(NULL, nfsserver_syscalls);
                if (error != 0) {
                        return error;
                }
                nfs_init();     /* XXX for monolithic kernel */
                netexport_init();
                nfsrv_initcache();      /* Init the server request cache */
                nfsrv_init(0);          /* Init server data structures */
                vfs_hooks_attach(&nfs_export_hooks);
                nfs_timer_srvinit(nfsrv_timer);
                return 0;
        case MODULE_CMD_FINI:
                error = syscall_disestablish(NULL, nfsserver_syscalls);
                if (error != 0) {
                        return error;
                }
                /*
                 * Kill export list before detaching VFS hooks, so we
                 * we don't leak state due to a concurrent umount().
                 */
                netexport_fini();
                vfs_hooks_detach(&nfs_export_hooks);

                /* Kill timer before server goes away. */
                nfs_timer_srvfini();
                nfsrv_fini();

                /* Server uses server cache, so kill cache last. */
                nfsrv_finicache();
                nfs_fini();
                return 0;
        case MODULE_CMD_AUTOUNLOAD:
                if (netexport_hasexports())
                        return EBUSY;
                /*FALLTHROUGH*/
        default:
                return ENOTTY;
        }
}

/*
 * nfs v3 access service
 */
int
nfsrv3_access(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, getret;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vattr va;
        u_long inmode, testmode, outmode;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam, &rdonly,
            (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(1, (struct vattr *)0);
                return (0);
        }
        inmode = fxdr_unsigned(u_int32_t, *tl);
        outmode = 0;
        if ((inmode & NFSV3ACCESS_READ) &&
            nfsrv_access(vp, VREAD, cred, rdonly, lwp, 0) == 0)
                outmode |= NFSV3ACCESS_READ;
        if (vp->v_type != VDIR) {
                testmode = inmode & (NFSV3ACCESS_MODIFY | NFSV3ACCESS_EXTEND);
                if (testmode &&
                    nfsrv_access(vp, VWRITE, cred, rdonly, lwp, 0) == 0)
                        outmode |= testmode;
                if ((inmode & NFSV3ACCESS_EXECUTE) &&
                    nfsrv_access(vp, VEXEC, cred, rdonly, lwp, 0) == 0)
                        outmode |= NFSV3ACCESS_EXECUTE;
        } else {
                testmode = inmode & (NFSV3ACCESS_MODIFY | NFSV3ACCESS_EXTEND |
                    NFSV3ACCESS_DELETE);
                if (testmode &&
                    nfsrv_access(vp, VWRITE, cred, rdonly, lwp, 0) == 0)
                        outmode |= testmode;
                if ((inmode & NFSV3ACCESS_LOOKUP) &&
                    nfsrv_access(vp, VEXEC, cred, rdonly, lwp, 0) == 0)
                        outmode |= NFSV3ACCESS_LOOKUP;
        }
        getret = VOP_GETATTR(vp, &va, cred);
        vput(vp);
        nfsm_reply(NFSX_POSTOPATTR(1) + NFSX_UNSIGNED);
        nfsm_srvpostop_attr(getret, &va);
        nfsm_build(tl, u_int32_t *, NFSX_UNSIGNED);
        *tl = txdr_unsigned(outmode);
        nfsm_srvdone;
}

/*
 * nfs getattr service
 */
int
nfsrv_getattr(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct nfs_fattr *fp;
        struct vattr va;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam, &rdonly,
            (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(0);
                return (0);
        }
        nqsrv_getl(vp, ND_READ);
        error = VOP_GETATTR(vp, &va, cred);
        vput(vp);
        nfsm_reply(NFSX_FATTR(nfsd->nd_flag & ND_NFSV3));
        if (error)
                return (0);
        nfsm_build(fp, struct nfs_fattr *, NFSX_FATTR(nfsd->nd_flag & ND_NFSV3));
        nfsm_srvfillattr(&va, fp);
        nfsm_srvdone;
}

/*
 * nfs setattr service
 */
int
nfsrv_setattr(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vattr va, preat;
        struct nfsv2_sattr *sp;
        struct nfs_fattr *fp;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, preat_ret = 1, postat_ret = 1;
        int v3 = (nfsd->nd_flag & ND_NFSV3), gcheck = 0;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        u_quad_t frev;
        struct timespec guard;

        memset(&guard, 0, sizeof guard);        /* XXX gcc */

        nfsm_srvmtofh(&nsfh);
        vattr_null(&va);
        if (v3) {
                nfsm_srvsattr(&va);
                nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
                gcheck = fxdr_unsigned(int, *tl);
                if (gcheck) {
                        nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                        fxdr_nfsv3time(tl, &guard);
                }
        } else {
                nfsm_dissect(sp, struct nfsv2_sattr *, NFSX_V2SATTR);
                /*
                 * Nah nah nah nah na nah
                 * There is a bug in the Sun client that puts 0xffff in the mode
                 * field of sattr when it should put in 0xffffffff. The u_short
                 * doesn't sign extend.
                 * --> check the low order 2 bytes for 0xffff
                 */
                if ((fxdr_unsigned(int, sp->sa_mode) & 0xffff) != 0xffff)
                        va.va_mode = nfstov_mode(sp->sa_mode);
                if (sp->sa_uid != nfs_xdrneg1)
                        va.va_uid = fxdr_unsigned(uid_t, sp->sa_uid);
                if (sp->sa_gid != nfs_xdrneg1)
                        va.va_gid = fxdr_unsigned(gid_t, sp->sa_gid);
                if (sp->sa_size != nfs_xdrneg1)
                        va.va_size = fxdr_unsigned(u_quad_t, sp->sa_size);
                if (sp->sa_atime.nfsv2_sec != nfs_xdrneg1) {
#ifdef notyet
                        fxdr_nfsv2time(&sp->sa_atime, &va.va_atime);
#else
                        va.va_atime.tv_sec =
                                fxdr_unsigned(u_int32_t,sp->sa_atime.nfsv2_sec);
                        va.va_atime.tv_nsec = 0;
#endif
                }
                if (sp->sa_mtime.nfsv2_sec != nfs_xdrneg1)
                        fxdr_nfsv2time(&sp->sa_mtime, &va.va_mtime);

        }

        /*
         * Now that we have all the fields, lets do it.
         */
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam, &rdonly,
            (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvwcc_data(preat_ret, &preat, postat_ret, &va);
                return (0);
        }
        nqsrv_getl(vp, ND_WRITE);
        if (v3) {
                error = preat_ret = VOP_GETATTR(vp, &preat, cred);
                if (!error && gcheck &&
                        (preat.va_ctime.tv_sec != guard.tv_sec ||
                         preat.va_ctime.tv_nsec != guard.tv_nsec))
                        error = NFSERR_NOT_SYNC;
                if (error) {
                        vput(vp);
                        nfsm_reply(NFSX_WCCDATA(v3));
                        nfsm_srvwcc_data(preat_ret, &preat, postat_ret, &va);
                        return (0);
                }
        }

        /*
         * If the size is being changed write access is required, otherwise
         * just check for a read only file system.
         */
        if (va.va_size == ((u_quad_t)((quad_t) -1))) {
                if (rdonly || (vp->v_mount->mnt_flag & MNT_RDONLY)) {
                        error = EROFS;
                        goto out;
                }
        } else {
                if (vp->v_type == VDIR) {
                        error = EISDIR;
                        goto out;
                } else if ((error = nfsrv_access(vp, VWRITE, cred, rdonly,
                        lwp, 0)) != 0)
                        goto out;
        }
        error = VOP_SETATTR(vp, &va, cred);
        postat_ret = VOP_GETATTR(vp, &va, cred);
        if (!error)
                error = postat_ret;
out:
        vput(vp);
        nfsm_reply(NFSX_WCCORFATTR(v3));
        if (v3) {
                nfsm_srvwcc_data(preat_ret, &preat, postat_ret, &va);
                return (0);
        } else {
                nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                nfsm_srvfillattr(&va, fp);
        }
        nfsm_srvdone;
}

/*
 * nfs lookup rpc
 */
int
nfsrv_lookup(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct nfs_fattr *fp;
        struct nameidata nd, ind, *ndp = &nd;
        struct pathbuf *ipb = NULL;
        struct vnode *vp, *dirp;
        nfsrvfh_t nsfh;
        char *cp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, dirattr_ret = 1;
        uint32_t len;
        int v3 = (nfsd->nd_flag & ND_NFSV3), pubflag;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vattr va, dirattr;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);

        pubflag = nfs_ispublicfh(&nsfh);

        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = LOOKUP;
        nd.ni_cnd.cn_flags = LOCKLEAF;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, NULL, NULL,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), pubflag);

        if (!error && pubflag) {
                if (nd.ni_vp->v_type == VDIR && nfs_pub.np_index != NULL &&
                    (ipb = pathbuf_create(nfs_pub.np_index)) != NULL) {
                        /*
                         * Setup call to lookup() to see if we can find
                         * the index file. Arguably, this doesn't belong
                         * in a kernel.. Ugh.
                         */
                        ind = nd;
                        VOP_UNLOCK(nd.ni_vp);
                        ind.ni_pathbuf = ipb;

                        error = lookup_for_nfsd_index(&ind, nd.ni_vp);
                        if (!error) {
                                /*
                                 * Found an index file. Get rid of
                                 * the old references.
                                 */
                                if (dirp)
                                        vrele(dirp);
                                dirp = nd.ni_vp;
                                ndp = &ind;
                        } else
                                error = 0;
                }
                /*
                 * If the public filehandle was used, check that this lookup
                 * didn't result in a filehandle outside the publicly exported
                 * filesystem.
                 */

                if (!error && ndp->ni_vp->v_mount != nfs_pub.np_mount) {
                        vput(nd.ni_vp);
                        error = EPERM;
                }
        }

        if (error) {
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                }
                if (ipb != NULL) {
                        pathbuf_destroy(ipb);
                }
                if (dirp) {
                        if (v3) {
                                vn_lock(dirp, LK_SHARED | LK_RETRY);
                                dirattr_ret = VOP_GETATTR(dirp, &dirattr, cred);
                                vput(dirp);
                        } else
                                vrele(dirp);
                }
                nfsm_reply(NFSX_POSTOPATTR(v3));
                nfsm_srvpostop_attr(dirattr_ret, &dirattr);
                return (0);
        }

        nqsrv_getl(ndp->ni_startdir, ND_READ);
        pathbuf_destroy(nd.ni_pathbuf);
        if (ipb != NULL) {
                pathbuf_destroy(ipb);
        }
        vp = ndp->ni_vp;
        error = nfsrv_composefh(vp, &nsfh, v3);
        if (!error)
                error = VOP_GETATTR(vp, &va, cred);
        vput(vp);
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        dirattr_ret = VOP_GETATTR(dirp, &dirattr, cred);
                        vput(dirp);
                } else
                        vrele(dirp);
        }
        nfsm_reply(NFSX_SRVFH(&nsfh, v3) + NFSX_POSTOPORFATTR(v3) +
            NFSX_POSTOPATTR(v3));
        if (error) {
                nfsm_srvpostop_attr(dirattr_ret, &dirattr);
                return (0);
        }
        nfsm_srvfhtom(&nsfh, v3);
        if (v3) {
                nfsm_srvpostop_attr(0, &va);
                nfsm_srvpostop_attr(dirattr_ret, &dirattr);
        } else {
                nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                nfsm_srvfillattr(&va, fp);
        }
        nfsm_srvdone;
}

/*
 * nfs readlink service
 */
int
nfsrv_readlink(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct iovec iv[(NFS_MAXPATHLEN+MLEN-1)/MLEN];
        struct iovec *ivp = iv;
        struct mbuf *mp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, i, padlen, getret;
        uint32_t len;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mp2 = NULL, *mp3 = NULL, *mreq __unused;
        struct vnode *vp;
        struct vattr attr;
        nfsrvfh_t nsfh;
        struct uio io, *uiop = &io;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        len = 0;
        i = 0;
        while (len < NFS_MAXPATHLEN) {
                mp = m_get(M_WAIT, MT_DATA);
                MCLAIM(mp, &nfs_mowner);
                m_clget(mp, M_WAIT);
                mp->m_len = NFSMSIZ(mp);
                if (len == 0)
                        mp3 = mp2 = mp;
                else {
                        mp2->m_next = mp;
                        mp2 = mp;
                }
                if ((len+mp->m_len) > NFS_MAXPATHLEN) {
                        mp->m_len = NFS_MAXPATHLEN-len;
                        len = NFS_MAXPATHLEN;
                } else
                        len += mp->m_len;
                ivp->iov_base = mtod(mp, void *);
                ivp->iov_len = mp->m_len;
                i++;
                ivp++;
        }
        uiop->uio_iov = iv;
        uiop->uio_iovcnt = i;
        uiop->uio_offset = 0;
        uiop->uio_resid = len;
        uiop->uio_rw = UIO_READ;
        UIO_SETUP_SYSSPACE(uiop);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                m_freem(mp3);
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvpostop_attr(1, (struct vattr *)0);
                return (0);
        }
        if (vp->v_type != VLNK) {
                if (v3)
                        error = EINVAL;
                else
                        error = ENXIO;
                goto out;
        }
        nqsrv_getl(vp, ND_READ);
        error = VOP_READLINK(vp, uiop, cred);
out:
        getret = VOP_GETATTR(vp, &attr, cred);
        vput(vp);
        if (error)
                m_freem(mp3);
        nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_UNSIGNED);
        if (v3) {
                nfsm_srvpostop_attr(getret, &attr);
                if (error)
                        return (0);
        }
        len -= uiop->uio_resid;
        padlen = nfsm_padlen(len);
        if (len == 0) {
                m_freem(mp3);
                mp3 = NULL;
        } else if (uiop->uio_resid || padlen)
                nfs_zeropad(mp3, uiop->uio_resid, padlen);
        nfsm_build(tl, u_int32_t *, NFSX_UNSIGNED);
        *tl = txdr_unsigned(len);
        mb->m_next = mp3;
        nfsm_srvdone;
}

/*
 * nfs read service
 */
int
nfsrv_read(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct mbuf *m;
        struct nfs_fattr *fp;
        u_int32_t *tl;
        int32_t t1;
        int i;
        char *bpos;
        int error = 0, rdonly, cache = 0, getret;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        uint32_t reqlen, len, cnt, left;
        int padlen;
        char *cp2;
        struct mbuf *mb, *mreq;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        struct uio io, *uiop = &io;
        struct vattr va;
        off_t off;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        if (v3) {
                nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                off = fxdr_hyper(tl);
        } else {
                nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
                off = (off_t)fxdr_unsigned(u_int32_t, *tl);
        }
        nfsm_dissect(tl, uint32_t *, NFSX_UNSIGNED);
        reqlen = fxdr_unsigned(uint32_t, *tl);
        reqlen = MIN(reqlen, NFS_SRVMAXDATA(nfsd));
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvpostop_attr(1, (struct vattr *)0);
                return (0);
        }
        if (vp->v_type != VREG) {
                if (v3)
                        error = EINVAL;
                else
                        error = (vp->v_type == VDIR) ? EISDIR : EACCES;
        }
        if (!error) {
            nqsrv_getl(vp, ND_READ);
            if ((error = nfsrv_access(vp, VREAD, cred, rdonly, lwp, 1)) != 0)
                error = nfsrv_access(vp, VEXEC, cred, rdonly, lwp, 1);
        }
        getret = VOP_GETATTR(vp, &va, cred);
        if (!error)
                error = getret;
        if (error) {
                vput(vp);
                nfsm_reply(NFSX_POSTOPATTR(v3));
                nfsm_srvpostop_attr(getret, &va);
                return (0);
        }
        if (off >= va.va_size)
                cnt = 0;
        else if ((off + reqlen) > va.va_size)
                cnt = va.va_size - off;
        else
                cnt = reqlen;
        nfsm_reply(NFSX_POSTOPORFATTR(v3) + 3 * NFSX_UNSIGNED+nfsm_rndup(cnt));
        if (v3) {
                nfsm_build(tl, u_int32_t *, NFSX_V3FATTR + 4 * NFSX_UNSIGNED);
                *tl++ = nfs_true;
                fp = (struct nfs_fattr *)tl;
                tl += (NFSX_V3FATTR / sizeof (u_int32_t));
        } else {
                nfsm_build(tl, u_int32_t *, NFSX_V2FATTR + NFSX_UNSIGNED);
                fp = (struct nfs_fattr *)tl;
                tl += (NFSX_V2FATTR / sizeof (u_int32_t));
        }
        len = left = cnt;
        if (cnt > 0) {
                if (nfsd_use_loan) {
                        struct vm_page **pgpp;
                        voff_t pgoff = trunc_page(off);
                        int npages;
                        vaddr_t lva;

                        npages = (round_page(off + cnt) - pgoff) >> PAGE_SHIFT;
                        KASSERT(npages <= M_EXT_MAXPAGES); /* XXX */

                        /* allocate kva for mbuf data */
                        lva = sokvaalloc(pgoff, npages << PAGE_SHIFT,
                            slp->ns_so);
                        if (lva == 0) {
                                /* fall back to VOP_READ */
                                goto loan_fail;
                        }

                        /* allocate mbuf */
                        m = m_get(M_WAIT, MT_DATA);
                        MCLAIM(m, &nfs_mowner);
                        pgpp = m->m_ext.ext_pgs;

                        /* loan pages */
                        error = uvm_loanuobjpages(&vp->v_uobj, pgoff, npages,
                            pgpp);
                        if (error) {
                                sokvafree(lva, npages << PAGE_SHIFT);
                                m_free(m);
                                if (error == EBUSY)
                                        goto loan_fail;
                                goto read_error;
                        }

                        /* associate kva to mbuf */
                        MEXTADD(m, (void *)(lva + ((vaddr_t)off & PAGE_MASK)),
                            cnt, M_MBUF, soloanfree, slp->ns_so);
                        m->m_flags |= M_EXT_PAGES | M_EXT_ROMAP;
                        m->m_len = cnt;

                        /* map pages */
                        for (i = 0; i < npages; i++) {
                                pmap_kenter_pa(lva, VM_PAGE_TO_PHYS(pgpp[i]),
                                    VM_PROT_READ, 0);
                                lva += PAGE_SIZE;
                        }

                        pmap_update(pmap_kernel());

                        mb->m_next = m;
                        mb = m;
                        error = 0;
                        uiop->uio_resid = 0;
                } else {
                        struct iovec *iv;
                        struct iovec *iv2;
                        struct mbuf *m2;
                        int siz;
loan_fail:
                        /*
                         * Generate the mbuf list with the uio_iov ref. to it.
                         */
                        i = 0;
                        m = m2 = mb;
                        while (left > 0) {
                                siz = uimin(M_TRAILINGSPACE(m), left);
                                if (siz > 0) {
                                        left -= siz;
                                        i++;
                                }
                                if (left > 0) {
                                        m = m_get(M_WAIT, MT_DATA);
                                        MCLAIM(m, &nfs_mowner);
                                        m_clget(m, M_WAIT);
                                        m->m_len = 0;
                                        m2->m_next = m;
                                        m2 = m;
                                }
                        }
                        iv = malloc(i * sizeof(struct iovec), M_TEMP, M_WAITOK);
                        uiop->uio_iov = iv2 = iv;
                        m = mb;
                        left = cnt;
                        i = 0;
                        while (left > 0) {
                                if (m == NULL)
                                        panic("nfsrv_read iov");
                                siz = uimin(M_TRAILINGSPACE(m), left);
                                if (siz > 0) {
                                        iv->iov_base = mtod(m, char *) +
                                            m->m_len;
                                        iv->iov_len = siz;
                                        m->m_len += siz;
                                        left -= siz;
                                        iv++;
                                        i++;
                                }
                                m = m->m_next;
                        }
                        uiop->uio_iovcnt = i;
                        uiop->uio_offset = off;
                        uiop->uio_resid = cnt;
                        uiop->uio_rw = UIO_READ;
                        UIO_SETUP_SYSSPACE(uiop);
                        error = VOP_READ(vp, uiop, IO_NODELOCKED, cred);
                        free((void *)iv2, M_TEMP);
                }
read_error:
                if (error || (getret = VOP_GETATTR(vp, &va, cred)) != 0){
                        if (!error)
                                error = getret;
                        m_freem(mreq);
                        vput(vp);
                        nfsm_reply(NFSX_POSTOPATTR(v3));
                        nfsm_srvpostop_attr(getret, &va);
                        return (0);
                }
        } else {
                uiop->uio_resid = 0;
        }
        vput(vp);
        nfsm_srvfillattr(&va, fp);
        len -= uiop->uio_resid;
        padlen = nfsm_padlen(len);
        if (uiop->uio_resid || padlen)
                nfs_zeropad(mb, uiop->uio_resid, padlen);
        if (v3) {
                /* count */
                *tl++ = txdr_unsigned(len);
                /* eof */
                if (off + len >= va.va_size)
                        *tl++ = nfs_true;
                else
                        *tl++ = nfs_false;
        }
        *tl = txdr_unsigned(len);
        nfsm_srvdone;
}

/*
 * nfs write service
 */
int
nfsrv_write(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct iovec *ivp;
        int i, cnt;
        struct mbuf *mp;
        struct nfs_fattr *fp;
        struct iovec *iv;
        struct vattr va, forat;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, len, forat_ret = 1;
        int ioflags, aftat_ret = 1, retlen, zeroing, adjust;
        int stable = NFSV3WRITE_FILESYNC;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        struct uio io, *uiop = &io;
        off_t off;
        u_quad_t frev;

        if (mrep == NULL) {
                *mrq = NULL;
                return (0);
        }
        nfsm_srvmtofh(&nsfh);
        if (v3) {
                nfsm_dissect(tl, u_int32_t *, 5 * NFSX_UNSIGNED);
                off = fxdr_hyper(tl);
                tl += 3;
                stable = fxdr_unsigned(int, *tl++);
        } else {
                nfsm_dissect(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                off = (off_t)fxdr_unsigned(u_int32_t, *++tl);
                tl += 2;
        }
        retlen = len = fxdr_unsigned(int32_t, *tl);
        cnt = i = 0;

        /*
         * For NFS Version 2, it is not obvious what a write of zero length
         * should do, but I might as well be consistent with Version 3,
         * which is to return ok so long as there are no permission problems.
         */
        if (len > 0) {
                zeroing = 1;
                mp = mrep;
                while (mp) {
                        if (mp == md) {
                                zeroing = 0;
                                adjust = dpos - mtod(mp, char *);
                                mp->m_len -= adjust;
                                if (mp->m_len > 0 && adjust > 0)
                                        NFSMADV(mp, adjust);
                        }
                        if (zeroing)
                                mp->m_len = 0;
                        else if (mp->m_len > 0) {
                                i += mp->m_len;
                                if (i > len) {
                                        mp->m_len -= (i - len);
                                        zeroing = 1;
                                }
                                if (mp->m_len > 0)
                                        cnt++;
                        }
                        mp = mp->m_next;
                }
        }
        if (len > NFS_MAXDATA || len < 0 || i < len) {
                error = EIO;
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                return (0);
        }
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                return (0);
        }
        if (v3)
                forat_ret = VOP_GETATTR(vp, &forat, cred);
        if (vp->v_type != VREG) {
                if (v3)
                        error = EINVAL;
                else
                        error = (vp->v_type == VDIR) ? EISDIR : EACCES;
        }
        if (!error) {
                nqsrv_getl(vp, ND_WRITE);
                error = nfsrv_access(vp, VWRITE, cred, rdonly, lwp, 1);
        }
        if (error) {
                vput(vp);
                nfsm_reply(NFSX_WCCDATA(v3));
                nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                return (0);
        }

        if (len > 0) {
                ivp = malloc(cnt * sizeof (struct iovec), M_TEMP, M_WAITOK);
                uiop->uio_iov = iv = ivp;
                uiop->uio_iovcnt = cnt;
                mp = mrep;
                while (mp) {
                        if (mp->m_len > 0) {
                                ivp->iov_base = mtod(mp, void *);
                                ivp->iov_len = mp->m_len;
                                ivp++;
                        }
                        mp = mp->m_next;
                }

                /*
                 * XXX
                 * The IO_METASYNC flag indicates that all metadata (and not
                 * just enough to ensure data integrity) must be written to
                 * stable storage synchronously.
                 * (IO_METASYNC is not yet implemented in 4.4BSD-Lite.)
                 */
                if (stable == NFSV3WRITE_UNSTABLE)
                        ioflags = IO_NODELOCKED;
                else if (stable == NFSV3WRITE_DATASYNC)
                        ioflags = (IO_SYNC | IO_NODELOCKED);
                else
                        ioflags = (IO_METASYNC | IO_SYNC | IO_NODELOCKED);
                uiop->uio_resid = len;
                uiop->uio_rw = UIO_WRITE;
                uiop->uio_offset = off;
                UIO_SETUP_SYSSPACE(uiop);
                error = VOP_WRITE(vp, uiop, ioflags, cred);
                nfsstats.srvvop_writes++;
                free(iv, M_TEMP);
        }
        aftat_ret = VOP_GETATTR(vp, &va, cred);
        vput(vp);
        if (!error)
                error = aftat_ret;
        nfsm_reply(NFSX_PREOPATTR(v3) + NFSX_POSTOPORFATTR(v3) +
                2 * NFSX_UNSIGNED + NFSX_WRITEVERF(v3));
        if (v3) {
                nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                if (error)
                        return (0);
                nfsm_build(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                *tl++ = txdr_unsigned(retlen);
                if (stable == NFSV3WRITE_UNSTABLE)
                        *tl++ = txdr_unsigned(stable);
                else
                        *tl++ = txdr_unsigned(NFSV3WRITE_FILESYNC);
                /*
                 * Actually, there is no need to txdr these fields,
                 * but it may make the values more human readable,
                 * for debugging purposes.
                 */
                struct timeval btv;
                getmicroboottime(&btv);
                *tl++ = txdr_unsigned(btv.tv_sec);
                *tl = txdr_unsigned(btv.tv_usec);
        } else {
                nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                nfsm_srvfillattr(&va, fp);
        }
        nfsm_srvdone;
}

/*
 * XXX elad: the original NFSW_SAMECRED() macro also made sure the
 *           two nd_flag fields of the descriptors contained
 *           ND_KERBAUTH.
 */
static int
nfsrv_samecred(kauth_cred_t cred1, kauth_cred_t cred2)
{
        int i, do_ngroups;

        if (kauth_cred_geteuid(cred1) != kauth_cred_geteuid(cred2))
                return (0);
        if (kauth_cred_ngroups(cred1) != kauth_cred_ngroups(cred2))
                return (0);
        do_ngroups = kauth_cred_ngroups(cred1);
        for (i = 0; i < do_ngroups; i++)
                if (kauth_cred_group(cred1, i) !=
                    kauth_cred_group(cred2, i))
                        return (0);

        return (1);
}

static struct nfsrvw_delayhash *
nfsrv_nwdelayhash(struct nfssvc_sock *slp, const nfsrvfh_t *nsfh)
{
        uint32_t hash;

        hash = hash32_buf(NFSRVFH_DATA(nsfh), NFSRVFH_SIZE(nsfh),
            HASH32_BUF_INIT);
        return &slp->ns_wdelayhashtbl[hash % NFS_WDELAYHASHSIZ];
}

/*
 * NFS write service with write gathering support. Called when
 * nfsrvw_procrastinate > 0.
 * See: Chet Juszczak, "Improving the Write Performance of an NFS Server",
 * in Proc. of the Winter 1994 Usenix Conference, pg. 247-259, San Franscisco,
 * Jan. 1994.
 */
int
nfsrv_writegather(struct nfsrv_descript **ndp, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct timeval now;
        struct iovec *ivp;
        struct mbuf *mp;
        struct nfsrv_descript *wp, *nfsd, *owp, *swp;
        struct nfs_fattr *fp;
        int i = 0;
        struct iovec *iov;
        struct nfsrvw_delayhash *wpp;
        kauth_cred_t cred;
        struct vattr va, forat;
        u_int32_t *tl;
        int32_t t1;
        char *bpos, *dpos;
        int error = 0, rdonly, cache = 0, len = 0, forat_ret = 1;
        int ioflags, aftat_ret = 1, adjust, v3, zeroing;
        char *cp2;
        struct mbuf *mb, *mreq, *mrep, *md;
        struct vnode *vp;
        struct uio io, *uiop = &io;
        u_quad_t frev, cur_usec;

        *mrq = NULL;
        if (*ndp) {
            nfsd = *ndp;
            *ndp = NULL;
            mrep = nfsd->nd_mrep;
            md = nfsd->nd_md;
            dpos = nfsd->nd_dpos;
            cred = nfsd->nd_cr;
            v3 = (nfsd->nd_flag & ND_NFSV3);
            LIST_INIT(&nfsd->nd_coalesce);
            nfsd->nd_mreq = NULL;
            nfsd->nd_stable = NFSV3WRITE_FILESYNC;
            getmicrotime(&now);
            cur_usec = (u_quad_t)now.tv_sec * 1000000 + (u_quad_t)now.tv_usec;
            nfsd->nd_time = cur_usec + nfsrvw_procrastinate;

            /*
             * Now, get the write header..
             */
            nfsm_srvmtofh(&nfsd->nd_fh);
            if (v3) {
                nfsm_dissect(tl, u_int32_t *, 5 * NFSX_UNSIGNED);
                nfsd->nd_off = fxdr_hyper(tl);
                tl += 3;
                nfsd->nd_stable = fxdr_unsigned(int, *tl++);
            } else {
                nfsm_dissect(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                nfsd->nd_off = (off_t)fxdr_unsigned(u_int32_t, *++tl);
                tl += 2;
            }
            len = fxdr_unsigned(int32_t, *tl);
            nfsd->nd_len = len;
            nfsd->nd_eoff = nfsd->nd_off + len;

            /*
             * Trim the header out of the mbuf list and trim off any trailing
             * junk so that the mbuf list has only the write data.
             */
            zeroing = 1;
            i = 0;
            mp = mrep;
            while (mp) {
                if (mp == md) {
                    zeroing = 0;
                    adjust = dpos - mtod(mp, char *);
                    mp->m_len -= adjust;
                    if (mp->m_len > 0 && adjust > 0)
                        NFSMADV(mp, adjust);
                }
                if (zeroing)
                    mp->m_len = 0;
                else {
                    i += mp->m_len;
                    if (i > len) {
                        mp->m_len -= (i - len);
                        zeroing = 1;
                    }
                }
                mp = mp->m_next;
            }
            if (len > NFS_MAXDATA || len < 0  || i < len) {
nfsmout:
                m_freem(mrep);
                error = EIO;
                nfsm_writereply(2 * NFSX_UNSIGNED, v3);
                if (v3)
                    nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                nfsd->nd_mreq = mreq;
                nfsd->nd_mrep = NULL;
                nfsd->nd_time = 0;
            }

            /*
             * Add this entry to the hash and time queues.
             */
            owp = NULL;
            mutex_enter(&nfsd_lock);
            wp = LIST_FIRST(&slp->ns_tq);
            while (wp && wp->nd_time < nfsd->nd_time) {
                owp = wp;
                wp = LIST_NEXT(wp, nd_tq);
            }
            if (owp) {
                LIST_INSERT_AFTER(owp, nfsd, nd_tq);
            } else {
                LIST_INSERT_HEAD(&slp->ns_tq, nfsd, nd_tq);
            }
            if (nfsd->nd_mrep) {
                wpp = nfsrv_nwdelayhash(slp, &nfsd->nd_fh);
                owp = NULL;
                wp = LIST_FIRST(wpp);
                while (wp && nfsrv_comparefh(&nfsd->nd_fh, &wp->nd_fh)) {
                    owp = wp;
                    wp = LIST_NEXT(wp, nd_hash);
                }
                while (wp && wp->nd_off < nfsd->nd_off &&
                    !nfsrv_comparefh(&nfsd->nd_fh, &wp->nd_fh)) {
                    owp = wp;
                    wp = LIST_NEXT(wp, nd_hash);
                }
                if (owp) {
                    LIST_INSERT_AFTER(owp, nfsd, nd_hash);

                    /*
                     * Search the hash list for overlapping entries and
                     * coalesce.
                     */
                    for(; nfsd && NFSW_CONTIG(owp, nfsd); nfsd = wp) {
                        wp = LIST_NEXT(nfsd, nd_hash);
                        if (nfsrv_samecred(owp->nd_cr, nfsd->nd_cr))
                            nfsrvw_coalesce(owp, nfsd);
                    }
                } else {
                    LIST_INSERT_HEAD(wpp, nfsd, nd_hash);
                }
            }
            mutex_exit(&nfsd_lock);
        }

        /*
         * Now, do VOP_WRITE()s for any one(s) that need to be done now
         * and generate the associated reply mbuf list(s).
         */
loop1:
        getmicrotime(&now);
        cur_usec = (u_quad_t)now.tv_sec * 1000000 + (u_quad_t)now.tv_usec;
        mutex_enter(&nfsd_lock);
        for (nfsd = LIST_FIRST(&slp->ns_tq); nfsd; nfsd = owp) {
                owp = LIST_NEXT(nfsd, nd_tq);
                if (nfsd->nd_time > cur_usec)
                    break;
                if (nfsd->nd_mreq)
                    continue;
                LIST_REMOVE(nfsd, nd_tq);
                LIST_REMOVE(nfsd, nd_hash);
                mutex_exit(&nfsd_lock);

                mrep = nfsd->nd_mrep;
                nfsd->nd_mrep = NULL;
                cred = nfsd->nd_cr;
                v3 = (nfsd->nd_flag & ND_NFSV3);
                forat_ret = aftat_ret = 1;
                error = nfsrv_fhtovp(&nfsd->nd_fh, 1, &vp, cred, slp,
                    nfsd->nd_nam, &rdonly, (nfsd->nd_flag & ND_KERBAUTH),
                    false);
                if (!error) {
                    if (v3)
                        forat_ret = VOP_GETATTR(vp, &forat, cred);
                    if (vp->v_type != VREG) {
                        if (v3)
                            error = EINVAL;
                        else
                            error = (vp->v_type == VDIR) ? EISDIR : EACCES;
                    }
                } else
                    vp = NULL;
                if (!error) {
                    nqsrv_getl(vp, ND_WRITE);
                    error = nfsrv_access(vp, VWRITE, cred, rdonly, lwp, 1);
                }

                if (nfsd->nd_stable == NFSV3WRITE_UNSTABLE)
                    ioflags = IO_NODELOCKED;
                else if (nfsd->nd_stable == NFSV3WRITE_DATASYNC)
                    ioflags = (IO_SYNC | IO_NODELOCKED);
                else
                    ioflags = (IO_METASYNC | IO_SYNC | IO_NODELOCKED);
                uiop->uio_rw = UIO_WRITE;
                uiop->uio_offset = nfsd->nd_off;
                uiop->uio_resid = nfsd->nd_eoff - nfsd->nd_off;
                UIO_SETUP_SYSSPACE(uiop);
                if (uiop->uio_resid > 0) {
                    mp = mrep;
                    i = 0;
                    while (mp) {
                        if (mp->m_len > 0)
                            i++;
                        mp = mp->m_next;
                    }
                    uiop->uio_iovcnt = i;
                    iov = malloc(i * sizeof (struct iovec), M_TEMP, M_WAITOK);
                    uiop->uio_iov = ivp = iov;
                    mp = mrep;
                    while (mp) {
                        if (mp->m_len > 0) {
                            ivp->iov_base = mtod(mp, void *);
                            ivp->iov_len = mp->m_len;
                            ivp++;
                        }
                        mp = mp->m_next;
                    }
                    if (!error) {
                        error = VOP_WRITE(vp, uiop, ioflags, cred);
                        nfsstats.srvvop_writes++;
                    }
                    free((void *)iov, M_TEMP);
                }
                m_freem(mrep);
                if (vp) {
                    aftat_ret = VOP_GETATTR(vp, &va, cred);
                    vput(vp);
                }

                /*
                 * Loop around generating replies for all write rpcs that have
                 * now been completed.
                 */
                swp = nfsd;
                do {
                    if (error) {
                        nfsm_writereply(NFSX_WCCDATA(v3), v3);
                        if (v3) {
                            nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                        }
                    } else {
                        nfsm_writereply(NFSX_PREOPATTR(v3) +
                            NFSX_POSTOPORFATTR(v3) + 2 * NFSX_UNSIGNED +
                            NFSX_WRITEVERF(v3), v3);
                        if (v3) {
                            nfsm_srvwcc_data(forat_ret, &forat, aftat_ret, &va);
                            nfsm_build(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                            *tl++ = txdr_unsigned(nfsd->nd_len);
                            *tl++ = txdr_unsigned(swp->nd_stable);
                            /*
                             * Actually, there is no need to txdr these fields,
                             * but it may make the values more human readable,
                             * for debugging purposes.
                             */
                            struct timeval btv;
                            getmicroboottime(&btv);
                            *tl++ = txdr_unsigned(btv.tv_sec);
                            *tl = txdr_unsigned(btv.tv_usec);
                        } else {
                            nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                            nfsm_srvfillattr(&va, fp);
                        }
                    }
                    nfsd->nd_mreq = mreq;
                    if (nfsd->nd_mrep)
                        panic("nfsrv_write: nd_mrep not free");

                    /*
                     * Done. Put it at the head of the timer queue so that
                     * the final phase can return the reply.
                     */
                    mutex_enter(&nfsd_lock);
                    if (nfsd != swp) {
                        nfsd->nd_time = 0;
                        LIST_INSERT_HEAD(&slp->ns_tq, nfsd, nd_tq);
                    }
                    nfsd = LIST_FIRST(&swp->nd_coalesce);
                    if (nfsd) {
                        LIST_REMOVE(nfsd, nd_tq);
                    }
                    mutex_exit(&nfsd_lock);
                } while (nfsd);
                swp->nd_time = 0;

                mutex_enter(&nfsd_lock);
                LIST_INSERT_HEAD(&slp->ns_tq, swp, nd_tq);
                mutex_exit(&nfsd_lock);
                goto loop1;
        }
        mutex_exit(&nfsd_lock);
        nfs_timer_start();

        /*
         * Search for a reply to return.
         */
        mutex_enter(&nfsd_lock);
        LIST_FOREACH(nfsd, &slp->ns_tq, nd_tq) {
                if (nfsd->nd_mreq) {
                    LIST_REMOVE(nfsd, nd_tq);
                    *mrq = nfsd->nd_mreq;
                    *ndp = nfsd;
                    break;
                }
        }
        mutex_exit(&nfsd_lock);
        return (0);
}

/*
 * Coalesce the write request nfsd into owp. To do this we must:
 * - remove nfsd from the queues
 * - merge nfsd->nd_mrep into owp->nd_mrep
 * - update the nd_eoff and nd_stable for owp
 * - put nfsd on owp's nd_coalesce list
 * NB: Must be called at splsoftclock().
 */
void
nfsrvw_coalesce(struct nfsrv_descript *owp, struct nfsrv_descript *nfsd)
{
        int overlap;
        struct mbuf *mp;
        struct nfsrv_descript *m;

        KASSERT(mutex_owned(&nfsd_lock));

        LIST_REMOVE(nfsd, nd_hash);
        LIST_REMOVE(nfsd, nd_tq);
        if (owp->nd_eoff < nfsd->nd_eoff) {
            overlap = owp->nd_eoff - nfsd->nd_off;
            if (overlap < 0)
                panic("nfsrv_coalesce: bad off");
            if (overlap > 0)
                m_adj(nfsd->nd_mrep, overlap);
            mp = owp->nd_mrep;
            while (mp->m_next)
                mp = mp->m_next;
            mp->m_next = nfsd->nd_mrep;
            owp->nd_eoff = nfsd->nd_eoff;
        } else
            m_freem(nfsd->nd_mrep);
        nfsd->nd_mrep = NULL;
        if (nfsd->nd_stable == NFSV3WRITE_FILESYNC)
            owp->nd_stable = NFSV3WRITE_FILESYNC;
        else if (nfsd->nd_stable == NFSV3WRITE_DATASYNC &&
            owp->nd_stable == NFSV3WRITE_UNSTABLE)
            owp->nd_stable = NFSV3WRITE_DATASYNC;
        LIST_INSERT_HEAD(&owp->nd_coalesce, nfsd, nd_tq);
        /*
         * nfsd might hold coalesce elements! Move them to owp.
         * Otherwise, requests may be lost and clients will be stuck.
         */
        while ((m = LIST_FIRST(&nfsd->nd_coalesce)) != NULL) {
                LIST_REMOVE(m, nd_tq);
                LIST_INSERT_HEAD(&owp->nd_coalesce, m, nd_tq);
        }
}

/*
 * nfs create service
 * now does a truncate to 0 length via. setattr if it already exists
 */
int
nfsrv_create(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct nfs_fattr *fp;
        struct vattr va, dirfor, diraft;
        struct nfsv2_sattr *sp;
        u_int32_t *tl;
        struct nameidata nd;
        char *cp;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, len, tsize, dirfor_ret = 1, diraft_ret = 1;
        int rdev = 0, abort = 0;
        int v3 = (nfsd->nd_flag & ND_NFSV3), how, exclusive_flag = 0;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp = NULL, *dirp = NULL;
        nfsrvfh_t nsfh;
        u_quad_t frev, tempsize;
        u_char cverf[NFSX_V3CREATEVERF];

        nd.ni_cnd.cn_nameiop = 0;
        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = CREATE;
        nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_WCCDATA(v3));
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                if (dirp)
                        vrele(dirp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                return (0);
        }
        abort = 1;
        vattr_null(&va);
        if (v3) {
                va.va_mode = 0;
                nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
                how = fxdr_unsigned(int, *tl);
                switch (how) {
                case NFSV3CREATE_GUARDED:
                        if (nd.ni_vp) {
                                error = EEXIST;
                                break;
                        }
                        /* FALLTHROUGH */
                case NFSV3CREATE_UNCHECKED:
                        nfsm_srvsattr(&va);
                        break;
                case NFSV3CREATE_EXCLUSIVE:
                        nfsm_dissect(cp, void *, NFSX_V3CREATEVERF);
                        memcpy(cverf, cp, NFSX_V3CREATEVERF);
                        exclusive_flag = 1;
                        break;
                };
                va.va_type = VREG;
        } else {
                nfsm_dissect(sp, struct nfsv2_sattr *, NFSX_V2SATTR);
                va.va_type = IFTOVT(fxdr_unsigned(u_int32_t, sp->sa_mode));
                if (va.va_type == VNON)
                        va.va_type = VREG;
                va.va_mode = nfstov_mode(sp->sa_mode);
                switch (va.va_type) {
                case VREG:
                        tsize = fxdr_unsigned(int32_t, sp->sa_size);
                        if (tsize != -1)
                                va.va_size = (u_quad_t)tsize;
                        break;
                case VCHR:
                case VBLK:
                case VFIFO:
                        rdev = fxdr_unsigned(int32_t, sp->sa_size);
                        break;
                default:
                        break;
                };
        }

        /*
         * Iff doesn't exist, create it
         * otherwise just truncate to 0 length
         *   should I set the mode too ??
         */
        if (nd.ni_vp == NULL) {
                if (va.va_type == VREG || va.va_type == VSOCK) {
                        nqsrv_getl(nd.ni_dvp, ND_WRITE);
                        error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va);
                        if (!error) {
                                vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
                                if (exclusive_flag) {
                                        exclusive_flag = 0;
                                        vattr_null(&va);
                                        /*
                                         * XXX
                                         * assuming NFSX_V3CREATEVERF
                                         * == sizeof(nfstime3)
                                         */
                                        fxdr_nfsv3time(cverf, &va.va_atime);
                                        error = VOP_SETATTR(nd.ni_vp, &va,
                                                cred);
                                }
                        }
                } else if (va.va_type == VCHR || va.va_type == VBLK ||
                        va.va_type == VFIFO) {
                        if (va.va_type == VCHR && rdev == 0xffffffff)
                                va.va_type = VFIFO;
                        if (va.va_type != VFIFO &&
                            (error = kauth_authorize_system(cred,
                            KAUTH_SYSTEM_MKNOD, 0, NULL, NULL, NULL))) {
                                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                                vput(nd.ni_dvp);
                                abort = 0;
                                nfsm_reply(0);
                                if (nd.ni_pathbuf != NULL) {
                                        pathbuf_destroy(nd.ni_pathbuf);
                                        nd.ni_pathbuf = NULL;
                                }
                                return (error);
                        } else
                                va.va_rdev = (dev_t)rdev;
                        nqsrv_getl(nd.ni_dvp, ND_WRITE);
                        error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd,
                            &va);
                        if (!error) {
                                vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
                        } else {
                                nfsm_reply(0);
                        }
                } else {
                        VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                        if (nd.ni_pathbuf != NULL) {
                                pathbuf_destroy(nd.ni_pathbuf);
                                nd.ni_pathbuf = NULL;
                        }
                        error = ENXIO;
                        abort = 0;
                }
                vp = nd.ni_vp;
        } else {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                vp = nd.ni_vp;
                abort = 0;
                if (!error && va.va_size != -1) {
                        error = nfsrv_access(vp, VWRITE, cred,
                            (nd.ni_cnd.cn_flags & RDONLY), lwp, 0);
                        if (!error) {
                                nqsrv_getl(vp, ND_WRITE);
                                tempsize = va.va_size;
                                vattr_null(&va);
                                va.va_size = tempsize;
                                error = VOP_SETATTR(vp, &va, cred);
                        }
                }
                if (error)
                        vput(vp);
        }
        if (!error) {
                error = nfsrv_composefh(vp, &nsfh, v3);
                if (!error)
                        error = VOP_GETATTR(vp, &va, cred);
                vput(vp);
        }
        if (nd.ni_dvp == vp)
                vrele(nd.ni_dvp);
        else
                vput(nd.ni_dvp);
        if (v3) {
                if (exclusive_flag && !error) {
                        /*
                         * XXX assuming NFSX_V3CREATEVERF == sizeof(nfstime3)
                         */
                        char oldverf[NFSX_V3CREATEVERF];

                        txdr_nfsv3time(&va.va_atime, oldverf);
                        if (memcmp(cverf, oldverf, NFSX_V3CREATEVERF))
                                error = EEXIST;
                }
                if (dirp) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
        }
        if (dirp) {
                vrele(dirp);
                dirp = NULL;
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        abort = 0;
        nfsm_reply(NFSX_SRVFH(&nsfh, v3) + NFSX_FATTR(v3) + NFSX_WCCDATA(v3));
        if (v3) {
                if (!error) {
                        nfsm_srvpostop_fh(&nsfh);
                        nfsm_srvpostop_attr(0, &va);
                }
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
        } else {
                nfsm_srvfhtom(&nsfh, v3);
                nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                nfsm_srvfillattr(&va, fp);
        }
        return (0);
nfsmout:
        if (dirp)
                vrele(dirp);
        if (abort) {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vput(nd.ni_vp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
        }
        return (error);
}

/*
 * nfs v3 mknod service
 */
int
nfsrv_mknod(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vattr va, dirfor, diraft;
        u_int32_t *tl;
        struct nameidata nd;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, len, dirfor_ret = 1, diraft_ret = 1;
        int abort = 0;
        u_int32_t major, minor;
        enum vtype vtyp;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp, *dirp = (struct vnode *)0;
        nfsrvfh_t nsfh;
        u_quad_t frev;

        nd.ni_cnd.cn_nameiop = 0;
        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = CREATE;
        nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, &dirfor_ret, &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_WCCDATA(1));
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                if (dirp)
                        vrele(dirp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                return (0);
        }
        abort = 1;
        nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
        vtyp = nfsv3tov_type(*tl);
        if (vtyp != VCHR && vtyp != VBLK && vtyp != VSOCK && vtyp != VFIFO) {
                error = NFSERR_BADTYPE;
                goto abort;
        }
        vattr_null(&va);
        va.va_mode = 0;
        nfsm_srvsattr(&va);
        if (vtyp == VCHR || vtyp == VBLK) {
                dev_t rdev;

                nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                major = fxdr_unsigned(u_int32_t, *tl++);
                minor = fxdr_unsigned(u_int32_t, *tl);
                rdev = makedev(major, minor);
                if (major(rdev) != major || minor(rdev) != minor) {
                        error = EINVAL;
                        goto abort;
                }
                va.va_rdev = rdev;
        }

        /*
         * Iff doesn't exist, create it.
         */
        if (nd.ni_vp) {
                error = EEXIST;
abort:
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_vp)
                        vput(nd.ni_vp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                goto out;
        }
        va.va_type = vtyp;
        if (vtyp == VSOCK) {
                nqsrv_getl(nd.ni_dvp, ND_WRITE);
                error = VOP_CREATE(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va);
        } else {
                if (va.va_type != VFIFO &&
                    (error = kauth_authorize_system(cred,
                    KAUTH_SYSTEM_MKNOD, 0, NULL, NULL, NULL))) {
                        VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                        vput(nd.ni_dvp);
                        goto out;
                }
                nqsrv_getl(nd.ni_dvp, ND_WRITE);
                error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va);
                if (error)
                        goto out;
        }
        if (!error) {
                vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
        }
out:
        vp = nd.ni_vp;
        if (!error) {
                error = nfsrv_composefh(vp, &nsfh, true);
                if (!error)
                        error = VOP_GETATTR(vp, &va, cred);
                vput(vp);
        }
        if (nd.ni_dvp == nd.ni_vp)
                vrele(nd.ni_dvp);
        else
                vput(nd.ni_dvp);
        if (dirp) {
                vn_lock(dirp, LK_SHARED | LK_RETRY);
                diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                VOP_UNLOCK(dirp);
                vrele(dirp);
                dirp = NULL;
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        abort = 0;
        nfsm_reply(NFSX_SRVFH(&nsfh, true) + NFSX_POSTOPATTR(1) +
            NFSX_WCCDATA(1));
        if (!error) {
                nfsm_srvpostop_fh(&nsfh);
                nfsm_srvpostop_attr(0, &va);
        }
        nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
        return (0);
nfsmout:
        if (abort) {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vput(nd.ni_vp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
        }
        if (dirp)
                vrele(dirp);
        return (error);
}

/*
 * nfs remove service
 */
int
nfsrv_remove(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct nameidata nd;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, len, dirfor_ret = 1, diraft_ret = 1;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp, *dirp;
        struct vattr dirfor, diraft;
        nfsrvfh_t nsfh;
        u_quad_t frev;

#ifndef nolint
        vp = (struct vnode *)0;
#endif
        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = DELETE;
        nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (!error) {
                vp = nd.ni_vp;
                if (vp->v_type == VDIR) {
                        error = EPERM;
                        goto out;
                }
                /*
                 * The root of a mounted filesystem cannot be deleted.
                 */
                if (vp->v_vflag & VV_ROOT) {
                        error = EBUSY;
                }
out:
                if (!error) {
                        nqsrv_getl(nd.ni_dvp, ND_WRITE);
                        nqsrv_getl(vp, ND_WRITE);
                        error = VOP_REMOVE(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
                        vput(nd.ni_dvp);
                } else {
                        VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                        if (nd.ni_dvp == vp)
                                vrele(nd.ni_dvp);
                        else
                                vput(nd.ni_dvp);
                        vput(vp);
                }
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
                vrele(dirp);
        }
        nfsm_reply(NFSX_WCCDATA(v3));
        if (v3) {
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                return (0);
        }
        nfsm_srvdone;
}

/*
 * nfs rename service
 */
int
nfsrv_rename(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, fdirfor_ret = 1, fdiraft_ret = 1;
        uint32_t len, len2;
        int tdirfor_ret = 1, tdiraft_ret = 1;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct nameidata fromnd, tond;
        struct vnode *fvp, *tvp, *tdvp;
        struct vnode *fdirp = NULL, *tdirp = NULL;
        struct mount *localfs = NULL;
        struct vattr fdirfor, fdiraft, tdirfor, tdiraft;
        nfsrvfh_t fnsfh, tnsfh;
        u_quad_t frev;
        uid_t saved_uid;

#ifndef nolint
        fvp = (struct vnode *)0;
#endif
        fromnd.ni_cnd.cn_nameiop = 0;
        tond.ni_cnd.cn_nameiop = 0;
        nfsm_srvmtofh(&fnsfh);
        nfsm_srvnamesiz(len);
        /*
         * Remember our original uid so that we can reset cr_uid before
         * the second nfs_namei() call, in case it is remapped.
         */
        saved_uid = kauth_cred_geteuid(cred);
        fromnd.ni_cnd.cn_cred = cred;
        fromnd.ni_cnd.cn_nameiop = DELETE;
        fromnd.ni_cnd.cn_flags = LOCKPARENT;
        error = nfs_namei(&fromnd, &fnsfh, len, slp, nam, &md,
                &dpos, &fdirp, (v3 ? &fdirfor_ret : NULL), &fdirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                fromnd.ni_cnd.cn_nameiop = 0;
                nfsm_reply(2 * NFSX_WCCDATA(v3));
                nfsm_srvwcc_data(fdirfor_ret, &fdirfor, fdiraft_ret, &fdiraft);
                nfsm_srvwcc_data(tdirfor_ret, &tdirfor, tdiraft_ret, &tdiraft);
                if (fdirp)
                        vrele(fdirp);
                if (fromnd.ni_pathbuf != NULL) {
                        pathbuf_destroy(fromnd.ni_pathbuf);
                }
                return (0);
        }
        localfs = fromnd.ni_dvp->v_mount;
        fstrans_start(localfs);
        if (fromnd.ni_dvp != fromnd.ni_vp) {
                VOP_UNLOCK(fromnd.ni_dvp);
        }
        fvp = fromnd.ni_vp;

        error = VFS_RENAMELOCK_ENTER(localfs);
        if (error) {
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
                goto out1;
        }

        /* Copied, regrettably, from vfs_syscalls.c (q.v.) */
        vrele(fvp);
        if ((fromnd.ni_cnd.cn_namelen == 1 && 
             fromnd.ni_cnd.cn_nameptr[0] == '.') ||
            (fromnd.ni_cnd.cn_namelen == 2 && 
             fromnd.ni_cnd.cn_nameptr[0] == '.' &&
             fromnd.ni_cnd.cn_nameptr[1] == '.')) {
                error = EINVAL;
                VFS_RENAMELOCK_EXIT(localfs);
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                vrele(fromnd.ni_dvp);
                goto out1;
        }
        vn_lock(fromnd.ni_dvp, LK_EXCLUSIVE | LK_RETRY);
        error = relookup(fromnd.ni_dvp, &fromnd.ni_vp, &fromnd.ni_cnd, 0);
        if (error) {
                VOP_UNLOCK(fromnd.ni_dvp);
                VFS_RENAMELOCK_EXIT(localfs);
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                vrele(fromnd.ni_dvp);
                goto out1;
        }
        VOP_UNLOCK(fromnd.ni_vp);
        if (fromnd.ni_dvp != fromnd.ni_vp)
                VOP_UNLOCK(fromnd.ni_dvp);
        fvp = fromnd.ni_vp;

        nfsm_srvmtofh(&tnsfh);
        if (v3) {
                nfsm_dissect(tl, uint32_t *, NFSX_UNSIGNED);
                len2 = fxdr_unsigned(uint32_t, *tl);
                /* len2 will be checked by nfs_namei */
        }
        else {
                /* NFSv2 */
                nfsm_strsiz(len2, NFS_MAXNAMLEN);
        }
        kauth_cred_seteuid(cred, saved_uid);
        tond.ni_cnd.cn_cred = cred;
        tond.ni_cnd.cn_nameiop = RENAME;
        tond.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF | NOCACHE;
        error = nfs_namei(&tond, &tnsfh, len2, slp, nam, &md,
                &dpos, &tdirp, (v3 ? &tdirfor_ret : NULL), &tdirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                VFS_RENAMELOCK_EXIT(localfs);
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
                goto out1;
        }
        tdvp = tond.ni_dvp;
        tvp = tond.ni_vp;
        if (tvp != NULL) {
                if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
                        if (v3)
                                error = EEXIST;
                        else
                                error = EISDIR;
                        goto out;
                } else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
                        if (v3)
                                error = EEXIST;
                        else
                                error = ENOTDIR;
                        goto out;
                }
                if (tvp->v_type == VDIR && tvp->v_mountedhere) {
                        if (v3)
                                error = EXDEV;
                        else
                                error = ENOTEMPTY;
                        goto out;
                }
        }
        if (fvp->v_type == VDIR && fvp->v_mountedhere) {
                if (v3)
                        error = EXDEV;
                else
                        error = ENOTEMPTY;
                goto out;
        }
        if (fvp->v_mount != tdvp->v_mount) {
                if (v3)
                        error = EXDEV;
                else
                        error = ENOTEMPTY;
                goto out;
        }
        if (fvp == tdvp) {
                if (v3)
                        error = EINVAL;
                else
                        error = ENOTEMPTY;
        }
        /*
         * If source is the same as the destination (that is the
         * same vnode with the same name in the same directory),
         * then there is nothing to do.
         */
        if (fvp == tvp && fromnd.ni_dvp == tdvp &&
            fromnd.ni_cnd.cn_namelen == tond.ni_cnd.cn_namelen &&
            !memcmp(fromnd.ni_cnd.cn_nameptr, tond.ni_cnd.cn_nameptr,
              fromnd.ni_cnd.cn_namelen))
                error = -1;
out:
        if (!error) {
                nqsrv_getl(fromnd.ni_dvp, ND_WRITE);
                nqsrv_getl(tdvp, ND_WRITE);
                if (tvp) {
                        nqsrv_getl(tvp, ND_WRITE);
                }
                error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
                                   tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
                VFS_RENAMELOCK_EXIT(localfs);
        } else {
                VOP_ABORTOP(tond.ni_dvp, &tond.ni_cnd);
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                VFS_RENAMELOCK_EXIT(localfs);
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                vrele(fromnd.ni_dvp);
                vrele(fvp);
                if (error == -1)
                        error = 0;
        }
        if (tond.ni_pathbuf != NULL) {
                pathbuf_destroy(tond.ni_pathbuf);
                tond.ni_pathbuf = NULL;
        }
        tond.ni_cnd.cn_nameiop = 0;
out1:
        if (fdirp) {
                if (v3) {
                        vn_lock(fdirp, LK_SHARED | LK_RETRY);
                        fdiraft_ret = VOP_GETATTR(fdirp, &fdiraft, cred);
                        VOP_UNLOCK(fdirp);
                }
                vrele(fdirp);
                fdirp = NULL;
        }
        if (tdirp) {
                if (v3) {
                        vn_lock(tdirp, LK_SHARED | LK_RETRY);
                        tdiraft_ret = VOP_GETATTR(tdirp, &tdiraft, cred);
                        VOP_UNLOCK(tdirp);
                }
                vrele(tdirp);
                tdirp = NULL;
        }
        pathbuf_destroy(fromnd.ni_pathbuf);
        fromnd.ni_pathbuf = NULL;
        fromnd.ni_cnd.cn_nameiop = 0;
        fstrans_done(localfs);
        localfs = NULL;
        nfsm_reply(2 * NFSX_WCCDATA(v3));
        if (v3) {
                nfsm_srvwcc_data(fdirfor_ret, &fdirfor, fdiraft_ret, &fdiraft);
                nfsm_srvwcc_data(tdirfor_ret, &tdirfor, tdiraft_ret, &tdiraft);
        }
        return (0);

nfsmout:
        if (fdirp)
                vrele(fdirp);
#ifdef notdef
        if (tdirp)
                vrele(tdirp);
#endif
        if (tond.ni_cnd.cn_nameiop) {
                if (tond.ni_pathbuf != NULL) {
                        pathbuf_destroy(tond.ni_pathbuf);
                        tond.ni_pathbuf = NULL;
                }
        }
        if (localfs) {
                VFS_RENAMELOCK_EXIT(localfs);
                fstrans_done(localfs);
        }
        if (fromnd.ni_cnd.cn_nameiop) {
                VOP_ABORTOP(fromnd.ni_dvp, &fromnd.ni_cnd);
                if (fromnd.ni_pathbuf != NULL) {
                        pathbuf_destroy(fromnd.ni_pathbuf);
                        fromnd.ni_pathbuf = NULL;
                }
                vrele(fromnd.ni_dvp);
                vrele(fvp);
        }
        return (error);
}

/*
 * nfs link service
 */
int
nfsrv_link(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct nameidata nd;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, len, dirfor_ret = 1, diraft_ret = 1;
        int getret = 1, v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp, *xp, *dirp = (struct vnode *)0;
        struct vattr dirfor, diraft, at;
        nfsrvfh_t nsfh, dnsfh;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        nfsm_srvmtofh(&dnsfh);
        nfsm_srvnamesiz(len);
        error = nfsrv_fhtovp(&nsfh, false, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_WCCDATA(v3));
                nfsm_srvpostop_attr(getret, &at);
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                return (0);
        }
        if (vp->v_type == VDIR) {
                error = EPERM;
                goto out1;
        }
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = CREATE;
        nd.ni_cnd.cn_flags = LOCKPARENT;
        error = nfs_namei(&nd, &dnsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error)
                goto out1;
        xp = nd.ni_vp;
        if (xp != NULL) {
                error = EEXIST;
                goto out;
        }
        xp = nd.ni_dvp;
        if (vp->v_mount != xp->v_mount)
                error = EXDEV;
out:
        if (!error) {
                nqsrv_getl(vp, ND_WRITE);
                nqsrv_getl(xp, ND_WRITE);
                error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
                if (nd.ni_dvp != nd.ni_vp)
                        VOP_UNLOCK(nd.ni_dvp);
                vrele(nd.ni_dvp);
        } else {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vrele(nd.ni_vp);
        }
out1:
        if (v3) {
                vn_lock(vp, LK_SHARED | LK_RETRY);
                getret = VOP_GETATTR(vp, &at, cred);
                VOP_UNLOCK(vp);
        }
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
                vrele(dirp);
        }
        vrele(vp);
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_WCCDATA(v3));
        if (v3) {
                nfsm_srvpostop_attr(getret, &at);
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                return (0);
        }
        nfsm_srvdone;
}

/*
 * nfs symbolic link service
 */
int
nfsrv_symlink(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vattr va, dirfor, diraft;
        struct nameidata nd;
        u_int32_t *tl;
        int32_t t1;
        struct nfsv2_sattr *sp;
        char *bpos, *pathcp = NULL, *cp2;
        struct uio io;
        struct iovec iv;
        int error = 0, cache = 0, dirfor_ret = 1, diraft_ret = 1, abort = 0;
        uint32_t len, len2;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        struct mbuf *mb, *mreq __unused;
        struct vnode *dirp = (struct vnode *)0;
        nfsrvfh_t nsfh;
        u_quad_t frev;

        nd.ni_cnd.cn_nameiop = 0;
        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = CREATE;
        nd.ni_cnd.cn_flags = LOCKPARENT;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error)
                goto out;
        abort = 1;
        vattr_null(&va);
        va.va_type = VLNK;
        if (v3) {
                va.va_mode = 0;
                nfsm_srvsattr(&va);
                nfsm_dissect(tl, uint32_t *, NFSX_UNSIGNED);
                len2 = fxdr_unsigned(uint32_t, *tl);
                if (len2 > PATH_MAX) {
                        /* XXX should check _PC_NO_TRUNC */
                        error = ENAMETOOLONG;
                        goto abortop;
                }
        }
        else {
                /* NFSv2 */
                nfsm_strsiz(len2, NFS_MAXPATHLEN);
        }
        pathcp = malloc(len2 + 1, M_TEMP, M_WAITOK);
        iv.iov_base = pathcp;
        iv.iov_len = len2;
        io.uio_resid = len2;
        io.uio_offset = 0;
        io.uio_iov = &iv;
        io.uio_iovcnt = 1;
        io.uio_rw = UIO_READ;
        UIO_SETUP_SYSSPACE(&io);
        nfsm_mtouio(&io, len2);
        if (!v3) {
                nfsm_dissect(sp, struct nfsv2_sattr *, NFSX_V2SATTR);
                va.va_mode = fxdr_unsigned(u_int16_t, sp->sa_mode);
        }
        *(pathcp + len2) = '\0';
        if (nd.ni_vp) {
                error = EEXIST;
abortop:
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vrele(nd.ni_vp);
                goto out;
        }
        nqsrv_getl(nd.ni_dvp, ND_WRITE);
        error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va, pathcp);
        if (!error) {
            if (v3) {
                vn_lock(nd.ni_vp, LK_SHARED | LK_RETRY);
                error = nfsrv_composefh(nd.ni_vp, &nsfh, v3);
                if (!error)
                    error = VOP_GETATTR(nd.ni_vp, &va, cred);
                vput(nd.ni_vp);
            } else {
                vrele(nd.ni_vp);
            }
        }
        vput(nd.ni_dvp);
out:
        if (pathcp)
                free(pathcp, M_TEMP);
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
                vrele(dirp);
                dirp = NULL;
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        abort = 0;
        nfsm_reply(NFSX_SRVFH(&nsfh, v3) + NFSX_POSTOPATTR(v3) +
            NFSX_WCCDATA(v3));
        if (v3) {
                if (!error) {
                        nfsm_srvpostop_fh(&nsfh);
                        nfsm_srvpostop_attr(0, &va);
                }
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
        }
        return (0);
nfsmout:
        if (abort) {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vrele(nd.ni_vp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
        }
        if (dirp)
                vrele(dirp);
        if (pathcp)
                free(pathcp, M_TEMP);
        return (error);
}

/*
 * nfs mkdir service
 */
int
nfsrv_mkdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vattr va, dirfor, diraft;
        struct nfs_fattr *fp;
        struct nameidata nd;
        char *cp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, len, dirfor_ret = 1, diraft_ret = 1;
        int abort = 0;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp, *dirp = (struct vnode *)0;
        nfsrvfh_t nsfh;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = CREATE;
        nd.ni_cnd.cn_flags = LOCKPARENT;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                nfsm_reply(NFSX_WCCDATA(v3));
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                if (dirp)
                        vrele(dirp);
                return (0);
        }
        abort = 1;
        vattr_null(&va);
        if (v3) {
                va.va_mode = 0;
                nfsm_srvsattr(&va);
        } else {
                nfsm_dissect(tl, u_int32_t *, NFSX_UNSIGNED);
                va.va_mode = nfstov_mode(*tl++);
        }
        va.va_type = VDIR;
        vp = nd.ni_vp;
        if (vp != NULL) {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vrele(vp);
                error = EEXIST;
                goto out;
        }
        nqsrv_getl(nd.ni_dvp, ND_WRITE);
        error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &va);
        if (!error) {
                vp = nd.ni_vp;
                vn_lock(vp, LK_SHARED | LK_RETRY);
                error = nfsrv_composefh(vp, &nsfh, v3);
                if (!error)
                        error = VOP_GETATTR(vp, &va, cred);
                vput(vp);
        }
        vput(nd.ni_dvp);
out:
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
                vrele(dirp);
                dirp = NULL;
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        abort = 0;
        nfsm_reply(NFSX_SRVFH(&nsfh, v3) + NFSX_POSTOPATTR(v3) +
            NFSX_WCCDATA(v3));
        if (v3) {
                if (!error) {
                        nfsm_srvpostop_fh(&nsfh);
                        nfsm_srvpostop_attr(0, &va);
                }
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
        } else {
                nfsm_srvfhtom(&nsfh, v3);
                nfsm_build(fp, struct nfs_fattr *, NFSX_V2FATTR);
                nfsm_srvfillattr(&va, fp);
        }
        return (0);
nfsmout:
        if (abort) {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                if (nd.ni_vp)
                        vrele(nd.ni_vp);
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
        }
        if (dirp)
                vrele(dirp);
        return (error);
}

/*
 * nfs rmdir service
 */
int
nfsrv_rmdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, cache = 0, len, dirfor_ret = 1, diraft_ret = 1;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp, *dirp = (struct vnode *)0;
        struct vattr dirfor, diraft;
        nfsrvfh_t nsfh;
        struct nameidata nd;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        nfsm_srvnamesiz(len);
        nd.ni_cnd.cn_cred = cred;
        nd.ni_cnd.cn_nameiop = DELETE;
        nd.ni_cnd.cn_flags = LOCKPARENT | LOCKLEAF;
        error = nfs_namei(&nd, &nsfh, len, slp, nam, &md, &dpos,
                &dirp, (v3 ? &dirfor_ret : NULL), &dirfor,
                lwp, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                if (nd.ni_pathbuf != NULL) {
                        pathbuf_destroy(nd.ni_pathbuf);
                        nd.ni_pathbuf = NULL;
                }
                nfsm_reply(NFSX_WCCDATA(v3));
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                if (dirp)
                        vrele(dirp);
                return (0);
        }
        vp = nd.ni_vp;
        if (vp->v_type != VDIR) {
                error = ENOTDIR;
                goto out;
        }
        /*
         * No rmdir "." please.
         */
        if (nd.ni_dvp == vp) {
                error = EINVAL;
                goto out;
        }
        /*
         * The root of a mounted filesystem cannot be deleted.
         */
        if (vp->v_vflag & VV_ROOT)
                error = EBUSY;
out:
        if (!error) {
                nqsrv_getl(nd.ni_dvp, ND_WRITE);
                nqsrv_getl(vp, ND_WRITE);
                error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
                vput(nd.ni_dvp);
        } else {
                VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
                if (nd.ni_dvp == nd.ni_vp)
                        vrele(nd.ni_dvp);
                else
                        vput(nd.ni_dvp);
                vput(vp);
        }
        if (nd.ni_pathbuf != NULL) {
                pathbuf_destroy(nd.ni_pathbuf);
                nd.ni_pathbuf = NULL;
        }
        if (dirp) {
                if (v3) {
                        vn_lock(dirp, LK_SHARED | LK_RETRY);
                        diraft_ret = VOP_GETATTR(dirp, &diraft, cred);
                        VOP_UNLOCK(dirp);
                }
                vrele(dirp);
        }
        nfsm_reply(NFSX_WCCDATA(v3));
        if (v3) {
                nfsm_srvwcc_data(dirfor_ret, &dirfor, diraft_ret, &diraft);
                return (0);
        }
        nfsm_srvdone;
}

/*
 * nfs readdir service
 * - mallocs what it thinks is enough to read
 *      count rounded up to a multiple of NFS_SRVDIRBLKSIZ <= NFS_MAXREADDIR
 * - calls VOP_READDIR()
 * - loops around building the reply
 *      if the output generated exceeds count break out of loop
 *      The nfsm_clget macro is used here so that the reply will be packed
 *      tightly in mbuf clusters.
 * - it only knows that it has encountered eof when the VOP_READDIR()
 *      reads nothing
 * - as such one readdir rpc will return eof false although you are there
 *      and then the next will return eof
 * - it trims out records with d_fileno == 0
 *      this doesn't matter for Unix clients, but they might confuse clients
 *      for other os'.
 * - it trims out records with d_type == DT_WHT
 *      these cannot be seen through NFS (unless we extend the protocol)
 * NB: It is tempting to set eof to true if the VOP_READDIR() reads less
 *      than requested, but this may not apply to all filesystems. For
 *      example, client NFS does not { although it is never remote mounted
 *      anyhow }
 *     The alternate call nfsrv_readdirplus() does lookups as well.
 * PS: The NFS protocol spec. does not clarify what the "count" byte
 *      argument is a count of.. just name strings and file id's or the
 *      entire reply rpc or ...
 *      I tried just file name and id sizes and it confused the Sun client,
 *      so I am using the full rpc size now. The "paranoia.." comment refers
 *      to including the status longwords that are not a part of the dir.
 *      "entry" structures, but are in the rpc.
 */

#define NFS_SRVDIRBLKSIZ        1024

struct flrep {
        nfsuint64 fl_off;
        u_int32_t fl_postopok;
        struct nfs_fattr fl_fattr; /* XXX: must be of fattr3 size */
        u_int32_t fl_fhok;
        u_int32_t fl_fhsize;
        /* handle comes here, filled in dynamically */
};

int
nfsrv_readdir(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        char *bp, *be;
        struct mbuf *mp;
        struct dirent *dp;
        char *cp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        struct mbuf *mb, *mreq __unused, *mp2;
        char *cpos, *cend, *cp2, *rbuf;
        struct vnode *vp;
        struct vattr at;
        nfsrvfh_t nsfh;
        struct uio io;
        struct iovec iv;
        int len, nlen, rem, xfer, tsiz, i, error = 0, getret = 1;
        int siz, cnt, fullsiz, eofflag, rdonly, cache = 0, ncookies;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        u_quad_t frev, off, toff;
#ifdef NFS3_STRICTVERF
        u_quad_t verf;
#endif
        off_t *cookies = NULL, *cookiep;
        nfsuint64 jar;

        nfsm_srvmtofh(&nsfh);
        if (v3) {
                nfsm_dissect(tl, u_int32_t *, 5 * NFSX_UNSIGNED);
                toff = fxdr_hyper(tl);
                tl += 2;
#ifdef NFS3_STRICTVERF
                verf = fxdr_hyper(tl);
#endif
                tl += 2;
        } else {
                nfsm_dissect(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                toff = fxdr_unsigned(u_quad_t, *tl++);
        }
        off = toff;
        xfer = NFS_SRVMAXDATA(nfsd);
        cnt = fxdr_unsigned(int, *tl);
        if (cnt > xfer || cnt < 0)
                cnt = xfer;
        siz = ((cnt + NFS_SRVDIRBLKSIZ - 1) & ~(NFS_SRVDIRBLKSIZ - 1));
        if (siz > xfer)
                siz = xfer;
        fullsiz = siz;
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (!error && vp->v_type != VDIR) {
                error = ENOTDIR;
                vput(vp);
        }
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        nqsrv_getl(vp, ND_READ);
        if (v3) {
                error = getret = VOP_GETATTR(vp, &at, cred);
#ifdef NFS3_STRICTVERF
                /*
                 * XXX This check is too strict for Solaris 2.5 clients.
                 */
                if (!error && toff && verf != at.va_filerev)
                        error = NFSERR_BAD_COOKIE;
#endif
        }
        if (!error)
                error = nfsrv_access(vp, VEXEC, cred, rdonly, lwp, 0);
        if (error) {
                vput(vp);
                nfsm_reply(NFSX_POSTOPATTR(v3));
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        VOP_UNLOCK(vp);
        rbuf = malloc(siz, M_TEMP, M_WAITOK);
again:
        iv.iov_base = rbuf;
        iv.iov_len = fullsiz;
        io.uio_iov = &iv;
        io.uio_iovcnt = 1;
        io.uio_offset = (off_t)off;
        io.uio_resid = fullsiz;
        io.uio_rw = UIO_READ;
        UIO_SETUP_SYSSPACE(&io);
        eofflag = 0;
        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);

        error = VOP_READDIR(vp, &io, cred, &eofflag, &cookies, &ncookies);

        off = (off_t)io.uio_offset;
        if (!cookies && !error)
                error = NFSERR_PERM;
        if (v3) {
                getret = VOP_GETATTR(vp, &at, cred);
                if (!error)
                        error = getret;
        }

        VOP_UNLOCK(vp);
        if (error) {
                vrele(vp);
                free((void *)rbuf, M_TEMP);
                if (cookies)
                        free((void *)cookies, M_TEMP);
                nfsm_reply(NFSX_POSTOPATTR(v3));
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        if (io.uio_resid) {
                siz -= io.uio_resid;

                /*
                 * If nothing read, return eof
                 * rpc reply
                 */
                if (siz == 0) {
                        vrele(vp);
                        nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_COOKIEVERF(v3) +
                                2 * NFSX_UNSIGNED);
                        if (v3) {
                                nfsm_srvpostop_attr(getret, &at);
                                nfsm_build(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                                txdr_hyper(at.va_filerev, tl);
                                tl += 2;
                        } else
                                nfsm_build(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                        *tl++ = nfs_false;
                        *tl = nfs_true;
                        free((void *)rbuf, M_TEMP);
                        free((void *)cookies, M_TEMP);
                        return (0);
                }
        }

        /*
         * Check for degenerate cases of nothing useful read.
         * If so go try again
         */
        cpos = rbuf;
        cend = rbuf + siz;
        dp = (struct dirent *)cpos;
        cookiep = cookies;

        while (cpos < cend && ncookies > 0 &&
                (dp->d_fileno == 0 || dp->d_type == DT_WHT)) {
                cpos += dp->d_reclen;
                dp = (struct dirent *)cpos;
                cookiep++;
                ncookies--;
        }
        if (cpos >= cend || ncookies == 0) {
                toff = off;
                siz = fullsiz;
                free(cookies, M_TEMP);
                cookies = NULL;
                goto again;
        }

        len = 3 * NFSX_UNSIGNED;        /* paranoia, probably can be 0 */
        nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_COOKIEVERF(v3) + siz);
        if (v3) {
                nfsm_srvpostop_attr(getret, &at);
                nfsm_build(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                txdr_hyper(at.va_filerev, tl);
        }
        mp = mp2 = mb;
        bp = bpos;
        be = bp + M_TRAILINGSPACE(mp);

        /* Loop through the records and build reply */
        while (cpos < cend && ncookies > 0) {
                if (dp->d_fileno != 0 && dp->d_type != DT_WHT) {
                        nlen = dp->d_namlen;
                        rem = nfsm_rndup(nlen)-nlen;
                        len += (4 * NFSX_UNSIGNED + nlen + rem);
                        if (v3)
                                len += 2 * NFSX_UNSIGNED;
                        if (len > cnt) {
                                eofflag = 0;
                                break;
                        }
                        /*
                         * Build the directory record xdr from
                         * the dirent entry.
                         */
                        nfsm_clget;
                        *tl = nfs_true;
                        bp += NFSX_UNSIGNED;
                        if (v3) {
                                nfsm_clget;
                                *tl = txdr_unsigned(dp->d_fileno >> 32);
                                bp += NFSX_UNSIGNED;
                        }
                        nfsm_clget;
                        *tl = txdr_unsigned(dp->d_fileno);
                        bp += NFSX_UNSIGNED;
                        nfsm_clget;
                        *tl = txdr_unsigned(nlen);
                        bp += NFSX_UNSIGNED;

                        /* And loop around copying the name */
                        xfer = nlen;
                        cp = dp->d_name;
                        while (xfer > 0) {
                                nfsm_clget;
                                if ((bp+xfer) > be)
                                        tsiz = be-bp;
                                else
                                        tsiz = xfer;
                                memcpy(bp, cp, tsiz);
                                bp += tsiz;
                                xfer -= tsiz;
                                if (xfer > 0)
                                        cp += tsiz;
                        }
                        /* And null pad to an int32_t boundary */
                        for (i = 0; i < rem; i++)
                                *bp++ = '\0';
                        nfsm_clget;

                        /* Finish off the record */
                        txdr_hyper(*cookiep, &jar);
                        if (v3) {
                                *tl = jar.nfsuquad[0];
                                bp += NFSX_UNSIGNED;
                                nfsm_clget;
                        }
                        *tl = jar.nfsuquad[1];
                        bp += NFSX_UNSIGNED;
                }
                cpos += dp->d_reclen;
                dp = (struct dirent *)cpos;
                cookiep++;
                ncookies--;
        }
        vrele(vp);
        nfsm_clget;
        *tl = nfs_false;
        bp += NFSX_UNSIGNED;
        nfsm_clget;
        if (eofflag)
                *tl = nfs_true;
        else
                *tl = nfs_false;
        bp += NFSX_UNSIGNED;
        if (mp != mb) {
                if (bp < be)
                        mp->m_len = bp - mtod(mp, char *);
        } else
                mp->m_len += bp - bpos;
        free((void *)rbuf, M_TEMP);
        free((void *)cookies, M_TEMP);
        nfsm_srvdone;
}

int
nfsrv_readdirplus(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        char *bp, *be;
        struct mbuf *mp;
        struct dirent *dp;
        char *cp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        struct mbuf *mb, *mreq __unused, *mp2;
        char *cpos, *cend, *cp2, *rbuf;
        struct vnode *vp, *nvp;
        struct flrep fl;
        nfsrvfh_t nsfh;
        struct uio io;
        struct iovec iv;
        struct vattr va, at, *vap = &va;
        struct nfs_fattr *fp;
        int len, nlen, rem, xfer, tsiz, i, error = 0, getret = 1;
        int siz, cnt, fullsiz, eofflag, rdonly, cache = 0, dirlen, ncookies;
        u_quad_t frev, off, toff;
#ifdef NFS3_STRICTVERF
        u_quad_t verf;
#endif
        off_t *cookies = NULL, *cookiep;

        nfsm_srvmtofh(&nsfh);
        nfsm_dissect(tl, u_int32_t *, 6 * NFSX_UNSIGNED);
        toff = fxdr_hyper(tl);
        tl += 2;
#ifdef NFS3_STRICTVERF
        verf = fxdr_hyper(tl);
#endif
        tl += 2;
        off = toff;
        xfer = NFS_SRVMAXDATA(nfsd);
        siz = fxdr_unsigned(int, *tl++);
        if (siz > xfer || siz < 0)
                siz = xfer;
        cnt = fxdr_unsigned(int, *tl);
        if (cnt > xfer || cnt < 0)
                cnt = xfer;
        siz = ((siz + NFS_SRVDIRBLKSIZ - 1) & ~(NFS_SRVDIRBLKSIZ - 1));
        if (siz > xfer)
                siz = xfer;
        fullsiz = siz;
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (!error && vp->v_type != VDIR) {
                error = ENOTDIR;
                vput(vp);
        }
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        error = getret = VOP_GETATTR(vp, &at, cred);
#ifdef NFS3_STRICTVERF
        /*
         * XXX This check is too strict for Solaris 2.5 clients.
         */
        if (!error && toff && verf != at.va_filerev)
                error = NFSERR_BAD_COOKIE;
#endif
        if (!error) {
                nqsrv_getl(vp, ND_READ);
                error = nfsrv_access(vp, VEXEC, cred, rdonly, lwp, 0);
        }
        if (error) {
                vput(vp);
                nfsm_reply(NFSX_V3POSTOPATTR);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        VOP_UNLOCK(vp);

        rbuf = malloc(siz, M_TEMP, M_WAITOK);
again:
        iv.iov_base = rbuf;
        iv.iov_len = fullsiz;
        io.uio_iov = &iv;
        io.uio_iovcnt = 1;
        io.uio_offset = (off_t)off;
        io.uio_resid = fullsiz;
        io.uio_rw = UIO_READ;
        UIO_SETUP_SYSSPACE(&io);
        eofflag = 0;

        vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);

        error = VOP_READDIR(vp, &io, cred, &eofflag, &cookies, &ncookies);

        off = (u_quad_t)io.uio_offset;
        getret = VOP_GETATTR(vp, &at, cred);

        VOP_UNLOCK(vp);

        /*
         * If the VGET operation doesn't work for this filesystem,
         * we can't support readdirplus. Returning NOTSUPP should
         * make clients fall back to plain readdir.
         * There's no need to check for VPTOFH as well, we wouldn't
         * even be here otherwise.
         */
        if (!getret) {
                if ((getret = VFS_VGET(vp->v_mount, at.va_fileid,
                    LK_EXCLUSIVE, &nvp)))
                        getret = (getret == EOPNOTSUPP) ?
                                NFSERR_NOTSUPP : NFSERR_IO;
                else
                        vput(nvp);
        }

        if (!cookies && !error)
                error = NFSERR_PERM;
        if (!error)
                error = getret;
        if (error) {
                vrele(vp);
                if (cookies)
                        free((void *)cookies, M_TEMP);
                free((void *)rbuf, M_TEMP);
                nfsm_reply(NFSX_V3POSTOPATTR);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        if (io.uio_resid) {
                siz -= io.uio_resid;

                /*
                 * If nothing read, return eof
                 * rpc reply
                 */
                if (siz == 0) {
                        vrele(vp);
                        nfsm_reply(NFSX_V3POSTOPATTR + NFSX_V3COOKIEVERF +
                                2 * NFSX_UNSIGNED);
                        nfsm_srvpostop_attr(getret, &at);
                        nfsm_build(tl, u_int32_t *, 4 * NFSX_UNSIGNED);
                        txdr_hyper(at.va_filerev, tl);
                        tl += 2;
                        *tl++ = nfs_false;
                        *tl = nfs_true;
                        free((void *)cookies, M_TEMP);
                        free((void *)rbuf, M_TEMP);
                        return (0);
                }
        }

        /*
         * Check for degenerate cases of nothing useful read.
         * If so go try again
         */
        cpos = rbuf;
        cend = rbuf + siz;
        dp = (struct dirent *)cpos;
        cookiep = cookies;

        while (cpos < cend && ncookies > 0 &&
                (dp->d_fileno == 0 || dp->d_type == DT_WHT)) {
                cpos += dp->d_reclen;
                dp = (struct dirent *)cpos;
                cookiep++;
                ncookies--;
        }
        if (cpos >= cend || ncookies == 0) {
                toff = off;
                siz = fullsiz;
                free(cookies, M_TEMP);
                cookies = NULL;
                goto again;
        }

        dirlen = len = NFSX_V3POSTOPATTR + NFSX_V3COOKIEVERF + 2 * NFSX_UNSIGNED;
        nfsm_reply(cnt);
        nfsm_srvpostop_attr(getret, &at);
        nfsm_build(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
        txdr_hyper(at.va_filerev, tl);
        mp = mp2 = mb;
        bp = bpos;
        be = bp + M_TRAILINGSPACE(mp);

        /* Loop through the records and build reply */
        while (cpos < cend && ncookies > 0) {
                if (dp->d_fileno != 0 && dp->d_type != DT_WHT) {
                        nfsrvfh_t nnsfh;

                        nlen = dp->d_namlen;
                        rem = nfsm_rndup(nlen)-nlen;

                        /*
                         * For readdir_and_lookup get the vnode using
                         * the file number.
                         */
                        if (VFS_VGET(vp->v_mount, dp->d_fileno, LK_EXCLUSIVE,
                            &nvp))
                                goto invalid;
                        if (nfsrv_composefh(nvp, &nnsfh, true)) {
                                vput(nvp);
                                goto invalid;
                        }
                        if (VOP_GETATTR(nvp, vap, cred)) {
                                vput(nvp);
                                goto invalid;
                        }
                        vput(nvp);

                        /*
                         * If either the dircount or maxcount will be
                         * exceeded, get out now. Both of these lengths
                         * are calculated conservatively, including all
                         * XDR overheads.
                         */
                        len += (8 * NFSX_UNSIGNED + nlen + rem + NFSX_V3FH +
                                NFSX_V3POSTOPATTR);
                        dirlen += (6 * NFSX_UNSIGNED + nlen + rem);
                        if (len > cnt || dirlen > fullsiz) {
                                eofflag = 0;
                                break;
                        }

                        /*
                         * Build the directory record xdr from
                         * the dirent entry.
                         */
                        fp = (struct nfs_fattr *)&fl.fl_fattr;
                        nfsm_srvfillattr(vap, fp);
                        fl.fl_fhsize = txdr_unsigned(NFSX_V3FH);
                        fl.fl_fhok = nfs_true;
                        fl.fl_postopok = nfs_true;
                        txdr_hyper(*cookiep, fl.fl_off.nfsuquad);

                        nfsm_clget;
                        *tl = nfs_true;
                        bp += NFSX_UNSIGNED;
                        nfsm_clget;
                        *tl = txdr_unsigned(dp->d_fileno >> 32);
                        bp += NFSX_UNSIGNED;
                        nfsm_clget;
                        *tl = txdr_unsigned(dp->d_fileno);
                        bp += NFSX_UNSIGNED;
                        nfsm_clget;
                        *tl = txdr_unsigned(nlen);
                        bp += NFSX_UNSIGNED;

                        /* And loop around copying the name */
                        xfer = nlen;
                        cp = dp->d_name;
                        while (xfer > 0) {
                                nfsm_clget;
                                if ((bp + xfer) > be)
                                        tsiz = be - bp;
                                else
                                        tsiz = xfer;
                                memcpy(bp, cp, tsiz);
                                bp += tsiz;
                                xfer -= tsiz;
                                if (xfer > 0)
                                        cp += tsiz;
                        }
                        /* And null pad to an int32_t boundary */
                        for (i = 0; i < rem; i++)
                                *bp++ = '\0';

                        /*
                         * Now copy the flrep structure out.
                         */
                        xfer = sizeof(struct flrep);
                        cp = (void *)&fl;
                        while (xfer > 0) {
                                nfsm_clget;
                                if ((bp + xfer) > be)
                                        tsiz = be - bp;
                                else
                                        tsiz = xfer;
                                memcpy(bp, cp, tsiz);
                                bp += tsiz;
                                xfer -= tsiz;
                                if (xfer > 0)
                                        cp += tsiz;
                        }

                        /*
                         * ... and filehandle.
                         */
                        xfer = NFSRVFH_SIZE(&nnsfh);
                        cp = NFSRVFH_DATA(&nnsfh);
                        while (xfer > 0) {
                                nfsm_clget;
                                if ((bp + xfer) > be)
                                        tsiz = be - bp;
                                else
                                        tsiz = xfer;
                                memcpy(bp, cp, tsiz);
                                bp += tsiz;
                                xfer -= tsiz;
                                if (xfer > 0)
                                        cp += tsiz;
                        }
                }
invalid:
                cpos += dp->d_reclen;
                dp = (struct dirent *)cpos;
                cookiep++;
                ncookies--;
        }
        vrele(vp);
        nfsm_clget;
        *tl = nfs_false;
        bp += NFSX_UNSIGNED;
        nfsm_clget;
        if (eofflag)
                *tl = nfs_true;
        else
                *tl = nfs_false;
        bp += NFSX_UNSIGNED;
        if (mp != mb) {
                if (bp < be)
                        mp->m_len = bp - mtod(mp, char *);
        } else
                mp->m_len += bp - bpos;
        free((void *)cookies, M_TEMP);
        free((void *)rbuf, M_TEMP);
        nfsm_srvdone;
}

/*
 * nfs commit service
 */
int
nfsrv_commit(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct vattr bfor, aft;
        struct vnode *vp;
        nfsrvfh_t nsfh;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, for_ret = 1, aft_ret = 1, cache = 0;
        uint32_t cnt;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        u_quad_t frev, off, end;

        nfsm_srvmtofh(&nsfh);
        nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);

        off = fxdr_hyper(tl);
        tl += 2;
        cnt = fxdr_unsigned(uint32_t, *tl);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(2 * NFSX_UNSIGNED);
                nfsm_srvwcc_data(for_ret, &bfor, aft_ret, &aft);
                return (0);
        }
        for_ret = VOP_GETATTR(vp, &bfor, cred);
        end = (cnt > 0) ? off + cnt : vp->v_size;
        if (end < off || end > vp->v_size)
                end = vp->v_size;
        if (off < vp->v_size)
                error = VOP_FSYNC(vp, cred, FSYNC_WAIT, off, end);
        /* else error == 0, from nfsrv_fhtovp() */
        aft_ret = VOP_GETATTR(vp, &aft, cred);
        vput(vp);
        nfsm_reply(NFSX_V3WCCDATA + NFSX_V3WRITEVERF);
        nfsm_srvwcc_data(for_ret, &bfor, aft_ret, &aft);
        if (!error) {
                nfsm_build(tl, u_int32_t *, NFSX_V3WRITEVERF);
                struct timeval btv;
                getmicroboottime(&btv);
                *tl++ = txdr_unsigned(btv.tv_sec);
                *tl = txdr_unsigned(btv.tv_usec);
        } else {
                return (0);
        }
        nfsm_srvdone;
}

/*
 * nfs statfs service
 */
int
nfsrv_statfs(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        struct statvfs *sf = NULL;
        struct nfs_statfs *sfp;
        u_int32_t *tl;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, getret = 1;
        int v3 = (nfsd->nd_flag & ND_NFSV3);
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp;
        struct vattr at;
        nfsrvfh_t nsfh;
        u_quad_t frev, tval;

        nfsm_srvmtofh(&nsfh);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        sf = malloc(sizeof(*sf), M_TEMP, M_WAITOK);
        error = VFS_STATVFS(vp->v_mount, sf);
        getret = VOP_GETATTR(vp, &at, cred);
        vput(vp);
        nfsm_reply(NFSX_POSTOPATTR(v3) + NFSX_STATFS(v3));
        if (v3)
                nfsm_srvpostop_attr(getret, &at);
        if (error) {
                free(sf, M_TEMP);
                return (0);
        }
        nfsm_build(sfp, struct nfs_statfs *, NFSX_STATFS(v3));
        if (v3) {
                tval = (u_quad_t)((quad_t)sf->f_blocks * (quad_t)sf->f_frsize);
                txdr_hyper(tval, &sfp->sf_tbytes);
                tval = (u_quad_t)((quad_t)sf->f_bfree * (quad_t)sf->f_frsize);
                txdr_hyper(tval, &sfp->sf_fbytes);
                tval = (u_quad_t)((quad_t)sf->f_bavail * (quad_t)sf->f_frsize);
                txdr_hyper(tval, &sfp->sf_abytes);
                tval = (u_quad_t)sf->f_files;
                txdr_hyper(tval, &sfp->sf_tfiles);
                tval = (u_quad_t)sf->f_ffree;
                txdr_hyper(tval, &sfp->sf_ffiles);
                txdr_hyper(tval, &sfp->sf_afiles);
                sfp->sf_invarsec = 0;
        } else {
                sfp->sf_tsize = txdr_unsigned(NFS_MAXDGRAMDATA);
                sfp->sf_bsize = txdr_unsigned(NFS_V2CLAMP16(sf->f_frsize));
                sfp->sf_blocks = txdr_unsigned(NFS_V2CLAMP32(sf->f_blocks));
                sfp->sf_bfree = txdr_unsigned(NFS_V2CLAMP32(sf->f_bfree));
                sfp->sf_bavail = txdr_unsigned(NFS_V2CLAMP32(sf->f_bavail));
        }
nfsmout:
        if (sf)
            free(sf, M_TEMP);
        return error;
}

/*
 * nfs fsinfo service
 */
int
nfsrv_fsinfo(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        u_int32_t *tl;
        struct nfsv3_fsinfo *sip;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, getret = 1;
        uint32_t maxdata;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp;
        struct vattr at;
        nfsrvfh_t nsfh;
        u_quad_t frev, maxfsize;
        struct statvfs *sb;

        nfsm_srvmtofh(&nsfh);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }

        /* XXX Try to make a guess on the max file size. */
        sb = malloc(sizeof(*sb), M_TEMP, M_WAITOK);
        VFS_STATVFS(vp->v_mount, sb);
        maxfsize = (u_quad_t)0x80000000 * sb->f_frsize - 1;
        free(sb, M_TEMP);

        getret = VOP_GETATTR(vp, &at, cred);
        vput(vp);
        nfsm_reply(NFSX_V3POSTOPATTR + NFSX_V3FSINFO);
        nfsm_srvpostop_attr(getret, &at);
        nfsm_build(sip, struct nfsv3_fsinfo *, NFSX_V3FSINFO);

        /*
         * XXX
         * There should be file system VFS OP(s) to get this information.
         * For now, assume ufs.
         */
        if (slp->ns_so->so_type == SOCK_DGRAM)
                maxdata = NFS_MAXDGRAMDATA;
        else
                maxdata = NFS_MAXDATA;
        sip->fs_rtmax = txdr_unsigned(maxdata);
        sip->fs_rtpref = txdr_unsigned(maxdata);
        sip->fs_rtmult = txdr_unsigned(NFS_FABLKSIZE);
        sip->fs_wtmax = txdr_unsigned(maxdata);
        sip->fs_wtpref = txdr_unsigned(maxdata);
        sip->fs_wtmult = txdr_unsigned(NFS_FABLKSIZE);
        sip->fs_dtpref = txdr_unsigned(maxdata);
        txdr_hyper(maxfsize, &sip->fs_maxfilesize);
        sip->fs_timedelta.nfsv3_sec = 0;
        sip->fs_timedelta.nfsv3_nsec = txdr_unsigned(1);
        sip->fs_properties = txdr_unsigned(NFSV3FSINFO_LINK |
                NFSV3FSINFO_SYMLINK | NFSV3FSINFO_HOMOGENEOUS |
                NFSV3FSINFO_CANSETTIME);
        nfsm_srvdone;
}

/*
 * nfs pathconf service
 */
int
nfsrv_pathconf(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp, struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep, *md = nfsd->nd_md;
        struct mbuf *nam = nfsd->nd_nam;
        char *dpos = nfsd->nd_dpos;
        kauth_cred_t cred = nfsd->nd_cr;
        u_int32_t *tl;
        struct nfsv3_pathconf *pc;
        int32_t t1;
        char *bpos;
        int error = 0, rdonly, cache = 0, getret = 1;
        register_t linkmax, namemax, chownres, notrunc;
        char *cp2;
        struct mbuf *mb, *mreq __unused;
        struct vnode *vp;
        struct vattr at;
        nfsrvfh_t nsfh;
        u_quad_t frev;

        nfsm_srvmtofh(&nsfh);
        error = nfsrv_fhtovp(&nsfh, 1, &vp, cred, slp, nam,
                 &rdonly, (nfsd->nd_flag & ND_KERBAUTH), false);
        if (error) {
                nfsm_reply(NFSX_UNSIGNED);
                nfsm_srvpostop_attr(getret, &at);
                return (0);
        }
        error = VOP_PATHCONF(vp, _PC_LINK_MAX, &linkmax);
        if (!error)
                error = VOP_PATHCONF(vp, _PC_NAME_MAX, &namemax);
        if (!error)
                error = VOP_PATHCONF(vp, _PC_CHOWN_RESTRICTED, &chownres);
        if (!error)
                error = VOP_PATHCONF(vp, _PC_NO_TRUNC, &notrunc);
        getret = VOP_GETATTR(vp, &at, cred);
        vput(vp);
        nfsm_reply(NFSX_V3POSTOPATTR + NFSX_V3PATHCONF);
        nfsm_srvpostop_attr(getret, &at);
        if (error)
                return (0);
        nfsm_build(pc, struct nfsv3_pathconf *, NFSX_V3PATHCONF);

        pc->pc_linkmax = txdr_unsigned(linkmax);
        pc->pc_namemax = txdr_unsigned(namemax);
        pc->pc_notrunc = txdr_unsigned(notrunc);
        pc->pc_chownrestricted = txdr_unsigned(chownres);

        /*
         * These should probably be supported by VOP_PATHCONF(), but
         * until msdosfs is exportable (why would you want to?), the
         * Unix defaults should be ok.
         */
        pc->pc_caseinsensitive = nfs_false;
        pc->pc_casepreserving = nfs_true;
        nfsm_srvdone;
}

/*
 * Null operation, used by clients to ping server
 */
/* ARGSUSED */
int
nfsrv_null(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
    struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep;
        char *bpos;
        int error = NFSERR_RETVOID, cache = 0;
        struct mbuf *mb, *mreq __unused;
        u_quad_t frev;

        nfsm_reply(0);
nfsmout:
        return (0);
}

/*
 * No operation, used for obsolete procedures
 */
/* ARGSUSED */
int
nfsrv_noop(struct nfsrv_descript *nfsd, struct nfssvc_sock *slp,
    struct lwp *lwp, struct mbuf **mrq)
{
        struct mbuf *mrep = nfsd->nd_mrep;
        char *bpos;
        int error, cache = 0;
        struct mbuf *mb, *mreq __unused;
        u_quad_t frev;

        if (nfsd->nd_repstat)
                error = nfsd->nd_repstat;
        else
                error = EPROCUNAVAIL;
        nfsm_reply(0);
nfsmout:
        return (0);
}

/*
 * Perform access checking for vnodes obtained from file handles that would
 * refer to files already opened by a Unix client. You cannot just use
 * vn_writechk() and VOP_ACCESS() for two reasons.
 * 1 - You must check for exported rdonly as well as MNT_RDONLY for the write case
 * 2 - The owner is to be given access irrespective of mode bits for some
 *     operations, so that processes that chmod after opening a file don't
 *     break. I don't like this because it opens a security hole, but since
 *     the nfs server opens a security hole the size of a barn door anyhow,
 *     what the heck.
 *
 * The exception to rule 2 is EPERM. If a file is IMMUTABLE, VOP_ACCESS()
 * will return EPERM instead of EACCES. EPERM is always an error.
 */
int
nfsrv_access(struct vnode *vp, int flags, kauth_cred_t cred, int rdonly, struct lwp *lwp, int override)
{
        struct vattr vattr;
        int error;
        if (flags & VWRITE) {
                /* Just vn_writechk() changed to check rdonly */
                /*
                 * Disallow write attempts on read-only file systems;
                 * unless the file is a socket or a block or character
                 * device resident on the file system.
                 */
                if (rdonly || (vp->v_mount->mnt_flag & MNT_RDONLY)) {
                        switch (vp->v_type) {
                        case VREG:
                        case VDIR:
                        case VLNK:
                                return (EROFS);
                        default:
                                break;
                        }
                }

                /*
                 * If the vnode is in use as a process's text,
                 * we can't allow writing.
                 */
                if (vp->v_iflag & VI_TEXT)
                        return (ETXTBSY);
        }
        error = VOP_GETATTR(vp, &vattr, cred);
        if (error)
                return (error);
        error = VOP_ACCESS(vp, flags, cred);
        /*
         * Allow certain operations for the owner (reads and writes
         * on files that are already open).
         */
        if (override && error == EACCES && kauth_cred_geteuid(cred) == vattr.va_uid)
                error = 0;
        return error;
}