/*
 * Copyright (c) 1982, 1986, 1989, 1993, 1995
 *      The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * 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.
 *
 *      @(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
 * $FreeBSD: src/sys/ufs/ufs/ufs_vnops.c,v 1.131.2.8 2003/01/02 17:26:19 bde Exp $
 */

#include "opt_quota.h"
#include "opt_suiddir.h"
#include "opt_ufs.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/filio.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/caps.h>
#include <sys/namei.h>
#include <sys/mount.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/lockf.h>
#include <sys/event.h>
#include <sys/conf.h>

#include <sys/file.h>           /* XXX */
#include <sys/jail.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>

#include <vfs/fifofs/fifo.h>

#include "quota.h"
#include "inode.h"
#include "dir.h"
#include "ufsmount.h"
#include "ufs_extern.h"
#include "ffs_extern.h"
#include "fs.h"
#ifdef UFS_DIRHASH
#include "dirhash.h"
#endif

static int ufs_access (struct vop_access_args *);
static int ufs_advlock (struct vop_advlock_args *);
static int ufs_chmod (struct vnode *, int, struct ucred *);
static int ufs_chown (struct vnode *, uid_t, gid_t, struct ucred *);
static int ufs_close (struct vop_close_args *);
static int ufs_create (struct vop_old_create_args *);
static int ufs_getattr (struct vop_getattr_args *);
static int ufs_link (struct vop_old_link_args *);
static int ufs_makeinode (int mode, struct vnode *, struct vnode **, struct componentname *);
static int ufs_markatime (struct vop_markatime_args *);
static int ufs_missingop (struct vop_generic_args *ap);
static int ufs_mkdir (struct vop_old_mkdir_args *);
static int ufs_mknod (struct vop_old_mknod_args *);
static int ufs_print (struct vop_print_args *);
static int ufs_readdir (struct vop_readdir_args *);
static int ufs_readlink (struct vop_readlink_args *);
static int ufs_remove (struct vop_old_remove_args *);
static int ufs_rename (struct vop_old_rename_args *);
static int ufs_rmdir (struct vop_old_rmdir_args *);
static int ufs_setattr (struct vop_setattr_args *);
static int ufs_strategy (struct vop_strategy_args *);
static int ufs_symlink (struct vop_old_symlink_args *);
static int ufs_whiteout (struct vop_old_whiteout_args *);
static int ufsfifo_close (struct vop_close_args *);
static int ufsfifo_kqfilter (struct vop_kqfilter_args *);
static int ufsfifo_read (struct vop_read_args *);
static int ufsfifo_write (struct vop_write_args *);
static int filt_ufsread (struct knote *kn, long hint);
static int filt_ufswrite (struct knote *kn, long hint);
static int filt_ufsvnode (struct knote *kn, long hint);
static void filt_ufsdetach (struct knote *kn);
static int ufs_kqfilter (struct vop_kqfilter_args *ap);

#define VN_KNOTE(vp, b) \
        KNOTE(&vp->v_pollinfo.vpi_kqinfo.ki_note, (b))

#define OFSFMT(vp)              ((vp)->v_mount->mnt_maxsymlinklen <= 0)

/*
 * A virgin directory (no blushing please).
 */
static struct dirtemplate mastertemplate = {
        0, 12, DT_DIR, 1, ".",
        0, DIRBLKSIZ - 12, DT_DIR, 2, ".."
};
static struct odirtemplate omastertemplate = {
        0, 12, 1, ".",
        0, DIRBLKSIZ - 12, 2, ".."
};

void
ufs_itimes(struct vnode *vp)
{
        struct inode *ip;
        struct timespec ts;

        ip = VTOI(vp);
        if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
                return;
        if ((vp->v_type == VBLK || vp->v_type == VCHR) && !DOINGSOFTDEP(vp))
                ip->i_flag |= IN_LAZYMOD;
        else
                ip->i_flag |= IN_MODIFIED;

        if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
                vfs_timestamp(&ts);
                if (ip->i_flag & IN_ACCESS) {
                        ip->i_atime = (uint32_t)ts.tv_sec;
                        ip->i_atime_ext = ts.tv_sec >> 32;
                        ip->i_atimensec = ts.tv_nsec;
                }
                if (ip->i_flag & IN_CHANGE) {
                        ip->i_ctime = (uint32_t)ts.tv_sec;
                        ip->i_ctime_ext = ts.tv_sec >> 32;
                        ip->i_ctimensec = ts.tv_nsec;
                }
                if (ip->i_flag & IN_UPDATE) {
                        if (ip->i_flag & IN_NOCOPYWRITE) {
                                if (vp->v_flag & VLASTWRITETS) {
                                        ip->i_mtime = (uint32_t)
                                                vp->v_lastwrite_ts.tv_sec;
                                        ip->i_mtime_ext =
                                                vp->v_lastwrite_ts.tv_sec >> 32;
                                        ip->i_mtimensec =
                                                vp->v_lastwrite_ts.tv_nsec;
                                }
                        } else {
                                ip->i_mtime = (uint32_t)ts.tv_sec;
                                ip->i_mtime_ext = ts.tv_sec >> 32;
                                ip->i_mtimensec = ts.tv_nsec;
                        }
                        ip->i_modrev++;
                }
        }
        ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
}

/*
 * Create a regular file
 *
 * ufs_create(struct vnode *a_dvp, struct vnode **a_vpp,
 *            struct componentname *a_cnp, struct vattr *a_vap)
 */
static
int
ufs_create(struct vop_old_create_args *ap)
{
        int error;

        error =
            ufs_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
            ap->a_dvp, ap->a_vpp, ap->a_cnp);
        if (error)
                return (error);
        VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        return (0);
}

/*
 * Mknod vnode call
 *
 * ufs_mknod(struct vnode *a_dvp, struct vnode **a_vpp,
 *           struct componentname *a_cnp, struct vattr *a_vap)
 */
/* ARGSUSED */
static
int
ufs_mknod(struct vop_old_mknod_args *ap)
{
        struct vattr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct inode *ip;
        ino_t ino;
        int error;

        /*
         * UFS cannot represent the entire major/minor range supported by
         * the kernel.
         */
        if (vap->va_rmajor != VNOVAL &&
            makeudev(vap->va_rmajor, vap->va_rminor) == NOUDEV) {
                return(EINVAL);
        }

        /* no special directory support */
        if (vap->va_type == VDIR)
                return(EINVAL);

        error = ufs_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
            ap->a_dvp, vpp, ap->a_cnp);
        if (error)
                return (error);
        VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        ip = VTOI(*vpp);
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        if (vap->va_rmajor != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                ip->i_rdev = makeudev(vap->va_rmajor, vap->va_rminor);
        }
        /*
         * Remove inode, then reload it through VFS_VGET so it is
         * checked to see if it is an alias of an existing entry in
         * the inode cache.
         */
        (*vpp)->v_type = VNON;
        ino = ip->i_number;     /* Save this before vgone() invalidates ip. */
        vgone_vxlocked(*vpp);
        vput(*vpp);
        error = VFS_VGET(ap->a_dvp->v_mount, NULL, ino, vpp);
        if (error) {
                *vpp = NULL;
                return (error);
        }
        return (0);
}

/*
 * Close called.
 *
 * Update the times on the inode.
 *
 * ufs_close(struct vnode *a_vp, int a_fflag)
 */
/* ARGSUSED */
static
int
ufs_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;

        if (VREFCNT(vp) > 1)
                ufs_itimes(vp);
        return (vop_stdclose(ap));
}

/*
 * ufs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred)
 */
static
int
ufs_access(struct vop_access_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int error;

#ifdef QUOTA
        if (ap->a_mode & VWRITE) {
                switch (vp->v_type) {
                case VDIR:
                case VLNK:
                case VREG:
                        if ((error = ufs_getinoquota(ip)) != 0)
                                return (error);
                        break;
                default:
                        break;
                }
        }
#endif

        error = vop_helper_access(ap, ip->i_uid, ip->i_gid, ip->i_mode, 0);
        return (error);
}

/*
 * ufs_getattr(struct vnode *a_vp, struct vattr *a_vap)
 */
/* ARGSUSED */
static
int
ufs_getattr(struct vop_getattr_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct vattr *vap = ap->a_vap;

        ufs_itimes(vp);
        /*
         * Copy from inode table
         */
        vap->va_fsid = devid_from_dev(ip->i_dev);
        vap->va_fileid = ip->i_number;
        vap->va_mode = ip->i_mode & ~IFMT;
        vap->va_nlink = VFSTOUFS(vp->v_mount)->um_i_effnlink_valid ?
            ip->i_effnlink : ip->i_nlink;
        vap->va_uid = ip->i_uid;
        vap->va_gid = ip->i_gid;
        vap->va_rmajor = umajor(ip->i_rdev);
        vap->va_rminor = uminor(ip->i_rdev);
        vap->va_size = ip->i_din.di_size;
        vap->va_atime.tv_sec =
                (time_t)(ip->i_atime | ((uint64_t)ip->i_atime_ext << 32));
        vap->va_atime.tv_nsec = ip->i_atimensec;
        vap->va_mtime.tv_sec =
                (time_t)(ip->i_mtime | ((uint64_t)ip->i_mtime_ext << 32));
        vap->va_mtime.tv_nsec = ip->i_mtimensec;
        vap->va_ctime.tv_sec =
                (time_t)(ip->i_ctime | ((uint64_t)ip->i_ctime_ext << 32));
        vap->va_ctime.tv_nsec = ip->i_ctimensec;
        vap->va_flags = ip->i_flags;
        vap->va_gen = ip->i_gen;
        vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
        vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
        vap->va_type = IFTOVT(ip->i_mode);
        vap->va_filerev = ip->i_modrev;
        return (0);
}

static
int
ufs_markatime(struct vop_markatime_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);

        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                return (EROFS);
        if (vp->v_mount->mnt_flag & MNT_NOATIME)
                return (0);
        ip->i_flag |= IN_ACCESS;
        VN_KNOTE(vp, NOTE_ATTRIB);
        return (0);
}

/*
 * Set attribute vnode op. called from several syscalls
 *
 * ufs_setattr(struct vnode *a_vp, struct vattr *a_vap,
 *              struct ucred *a_cred)
 */
static
int
ufs_setattr(struct vop_setattr_args *ap)
{
        struct vattr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct ucred *cred = ap->a_cred;
        int error;

        /*
         * Check for unsettable attributes.
         */
        if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
            (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
            (vap->va_blocksize != VNOVAL) || (vap->va_rmajor != VNOVAL) ||
            ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
                return (EINVAL);
        }
        if (vap->va_flags != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != ip->i_uid &&
                    (error = caps_priv_check(cred, SYSCAP_NOVFS_SETATTR)))
                {
                        return (error);
                }

                /*
                 * Note that a root chflags becomes a user chflags when
                 * we are jailed, unless the jail vfs_chflags sysctl
                 * is set.
                 */
                if (cred->cr_uid == 0 &&
                    (!jailed(cred) ||
                        PRISON_CAP_ISSET(cred->cr_prison->pr_caps,
                            PRISON_CAP_VFS_CHFLAGS))) {
                        if ((ip->i_flags
                            & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) &&
                            securelevel > 0)
                                return (EPERM);
                        ip->i_flags = vap->va_flags;
                } else {
                        if (ip->i_flags
                            & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
                            (vap->va_flags & UF_SETTABLE) != vap->va_flags)
                                return (EPERM);
                        ip->i_flags &= SF_SETTABLE;
                        ip->i_flags |= (vap->va_flags & UF_SETTABLE);
                }
                ip->i_flag |= IN_CHANGE;
                if (vap->va_flags & (IMMUTABLE | APPEND))
                        return (0);
        }
        if (ip->i_flags & (IMMUTABLE | APPEND))
                return (EPERM);
        /*
         * Go through the fields and update iff not VNOVAL.
         */
        if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if ((error = ufs_chown(vp, vap->va_uid, vap->va_gid, cred)) != 0)
                        return (error);
        }
        if (vap->va_size != VNOVAL) {
                /*
                 * Disallow write attempts on read-only filesystems;
                 * unless the file is a socket, fifo, or a block or
                 * character device resident on the filesystem.
                 */
                switch (vp->v_type) {
                case VDIR:
                        return (EISDIR);
                case VLNK:
                case VREG:
                        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                return (EROFS);
                        break;
                default:
                        break;
                }
                if ((error = ffs_truncate(vp, vap->va_size, 0, cred)) != 0)
                        return (error);
        }
        ip = VTOI(vp);
        if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != ip->i_uid &&
                    (error = caps_priv_check(cred, SYSCAP_NOVFS_SETATTR)) &&
                    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
                    (error = VOP_EACCESS(vp, VWRITE, cred))))
                {
                        return (error);
                }
                if (vap->va_atime.tv_sec != VNOVAL)
                        ip->i_flag |= IN_ACCESS;
                if (vap->va_mtime.tv_sec != VNOVAL)
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                ufs_itimes(vp);
                if (vap->va_atime.tv_sec != VNOVAL) {
                        ip->i_atime = (uint32_t)vap->va_atime.tv_sec;
                        ip->i_atime_ext = vap->va_atime.tv_sec >> 32;
                        ip->i_atimensec = vap->va_atime.tv_nsec;
                }
                if (vap->va_mtime.tv_sec != VNOVAL) {
                        ip->i_mtime = (uint32_t)vap->va_mtime.tv_sec;
                        ip->i_mtime_ext = vap->va_mtime.tv_sec >> 32;
                        ip->i_mtimensec = vap->va_mtime.tv_nsec;
                        vclrflags(vp, VLASTWRITETS);
                }
                error = ffs_update(vp, 0);
                if (error)
                        return (error);
        }
        error = 0;
        if (vap->va_mode != (mode_t)VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                error = ufs_chmod(vp, (int)vap->va_mode, cred);
        }
        VN_KNOTE(vp, NOTE_ATTRIB);
        return (error);
}

/*
 * Change the mode on a file.
 * Inode must be locked before calling.
 */
static int
ufs_chmod(struct vnode *vp, int mode, struct ucred *cred)
{
        struct inode *ip = VTOI(vp);
        int error;
        mode_t  cur_mode = ip->i_mode;

        error = vop_helper_chmod(vp, mode, cred, ip->i_uid, ip->i_gid,
                                 &cur_mode);
        if (error)
                return (error);
#if 0
        if (cred->cr_uid != ip->i_uid) {
            error = caps_priv_check(cred, SYSCAP_NOVFS_CHMOD);
            if (error)
                return (error);
        }
        if (cred->cr_uid) {
                if (vp->v_type != VDIR && (mode & S_ISTXT))
                        return (EFTYPE);
                if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
                        return (EPERM);
        }
#endif
        ip->i_mode = cur_mode;
        ip->i_flag |= IN_CHANGE;
        return (0);
}

/*
 * Perform chown operation on inode ip;
 * inode must be locked prior to call.
 */
static int
ufs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
{
        struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error = 0;
#ifdef QUOTA
        int i;
        long change;
#endif

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_gid;
        /*
         * If we don't own the file, are trying to change the owner
         * of the file, or are not a member of the target group,
         * the caller must be superuser or the call fails.
         */
        if ((cred->cr_uid != ip->i_uid || uid != ip->i_uid ||
            (gid != ip->i_gid && !(cred->cr_gid == gid ||
            groupmember(gid, cred)))) &&
            (error = caps_priv_check(cred, SYSCAP_NOVFS_CHOWN)))
        {
                return (error);
        }
        ogid = ip->i_gid;
        ouid = ip->i_uid;
#ifdef QUOTA
        if ((error = ufs_getinoquota(ip)) != 0)
                return (error);
        if (ouid == uid) {
                ufs_dqrele(vp, ip->i_dquot[USRQUOTA]);
                ip->i_dquot[USRQUOTA] = NODQUOT;
        }
        if (ogid == gid) {
                ufs_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                ip->i_dquot[GRPQUOTA] = NODQUOT;
        }
        change = ip->i_blocks;
        (void) ufs_chkdq(ip, -change, cred, CHOWN);
        (void) ufs_chkiq(ip, -1, cred, CHOWN);
        for (i = 0; i < MAXQUOTAS; i++) {
                ufs_dqrele(vp, ip->i_dquot[i]);
                ip->i_dquot[i] = NODQUOT;
        }
#endif
        ip->i_gid = gid;
        ip->i_uid = uid;
#ifdef QUOTA
        if ((error = ufs_getinoquota(ip)) == 0) {
                if (ouid == uid) {
                        ufs_dqrele(vp, ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        ufs_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                if ((error = ufs_chkdq(ip, change, cred, CHOWN)) == 0) {
                        if ((error = ufs_chkiq(ip, 1, cred, CHOWN)) == 0)
                                goto good;
                        else
                                (void)ufs_chkdq(ip, -change, cred, CHOWN|FORCE);
                }
                for (i = 0; i < MAXQUOTAS; i++) {
                        ufs_dqrele(vp, ip->i_dquot[i]);
                        ip->i_dquot[i] = NODQUOT;
                }
        }
        ip->i_gid = ogid;
        ip->i_uid = ouid;
        if (ufs_getinoquota(ip) == 0) {
                if (ouid == uid) {
                        ufs_dqrele(vp, ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        ufs_dqrele(vp, ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                (void) ufs_chkdq(ip, change, cred, FORCE|CHOWN);
                (void) ufs_chkiq(ip, 1, cred, FORCE|CHOWN);
                (void) ufs_getinoquota(ip);
        }
        return (error);
good:
        if (ufs_getinoquota(ip))
                panic("ufs_chown: lost quota");
#endif /* QUOTA */
        ip->i_flag |= IN_CHANGE;
        if (cred->cr_uid != 0 && (ouid != uid || ogid != gid))
                ip->i_mode &= ~(ISUID | ISGID);
        return (0);
}

/*
 * ufs_remove(struct vnode *a_dvp, struct vnode *a_vp,
 *            struct componentname *a_cnp)
 */
static
int
ufs_remove(struct vop_old_remove_args *ap)
{
        struct inode *ip;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        int error;

        ip = VTOI(vp);
#if 0   /* handled by kernel now */
        if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
            (VTOI(dvp)->i_flags & APPEND)) {
                error = EPERM;
                goto out;
        }
#endif
        error = ufs_dirremove(dvp, ip, ap->a_cnp->cn_flags, 0);
        VN_KNOTE(vp, NOTE_DELETE);
        VN_KNOTE(dvp, NOTE_WRITE);
#if 0
out:
#endif
        return (error);
}

/*
 * link vnode call
 *
 * ufs_link(struct vnode *a_tdvp, struct vnode *a_vp,
 *          struct componentname *a_cnp)
 */
static
int
ufs_link(struct vop_old_link_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip;
        struct direct newdir;
        int error;

        if (tdvp->v_mount != vp->v_mount) {
                error = EXDEV;
                goto out2;
        }
        if (tdvp != vp) {
                error = vn_lock(vp, LK_EXCLUSIVE | LK_FAILRECLAIM);
                if (error)
                        goto out2;
        }
        ip = VTOI(vp);
        if ((nlink_t)ip->i_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out1;
        }
#if 0   /* handled by kernel now, also DragonFly allows this */
        if (ip->i_flags & (IMMUTABLE | APPEND)) {
                error = EPERM;
                goto out1;
        }
#endif
        ip->i_effnlink++;
        ip->i_nlink++;
        ip->i_flag |= IN_CHANGE;
        if (DOINGSOFTDEP(vp))
                softdep_change_linkcnt(ip);
        error = ffs_update(vp, !(DOINGSOFTDEP(vp) | DOINGASYNC(vp)));
        if (!error) {
                ufs_makedirentry(ip, cnp, &newdir);
                error = ufs_direnter(tdvp, vp, &newdir, cnp, NULL);
        }

        if (error) {
                ip->i_effnlink--;
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                if (DOINGSOFTDEP(vp))
                        softdep_change_linkcnt(ip);
        }
out1:
        if (tdvp != vp)
                vn_unlock(vp);
out2:
        VN_KNOTE(vp, NOTE_LINK);
        VN_KNOTE(tdvp, NOTE_WRITE);
        return (error);
}

/*
 * whiteout vnode call
 *
 * ufs_whiteout(struct vnode *a_dvp, struct componentname *a_cnp, int a_flags)
 */
static
int
ufs_whiteout(struct vop_old_whiteout_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct direct newdir;
        int error = 0;

        switch (ap->a_flags) {
        case NAMEI_LOOKUP:
                /* 4.4 format directories support whiteout operations */
                if (dvp->v_mount->mnt_maxsymlinklen > 0)
                        return (0);
                return (EOPNOTSUPP);

        case NAMEI_CREATE:
                /* create a new directory whiteout */
#ifdef DIAGNOSTIC
                if (dvp->v_mount->mnt_maxsymlinklen <= 0)
                        panic("ufs_whiteout: old format filesystem");
#endif

                newdir.d_ino = UFS_WINO;
                newdir.d_namlen = cnp->cn_namelen;
                bcopy(cnp->cn_nameptr, newdir.d_name, (unsigned)cnp->cn_namelen + 1);
                newdir.d_type = DT_WHT;
                error = ufs_direnter(dvp, NULL, &newdir, cnp, NULL);
                break;

        case NAMEI_DELETE:
                /* remove an existing directory whiteout */
#ifdef DIAGNOSTIC
                if (dvp->v_mount->mnt_maxsymlinklen <= 0)
                        panic("ufs_whiteout: old format filesystem");
#endif

                cnp->cn_flags &= ~CNP_DOWHITEOUT;
                error = ufs_dirremove(dvp, NULL, cnp->cn_flags, 0);
                break;
        default:
                panic("ufs_whiteout: unknown op");
        }
        return (error);
}

/*
 * Rename system call.
 *      rename("foo", "bar");
 * is essentially
 *      unlink("bar");
 *      link("foo", "bar");
 *      unlink("foo");
 * but ``atomically''.  Can't do full commit without saving state in the
 * inode on disk which isn't feasible at this time.  Best we can do is
 * always guarantee the target exists.
 *
 * Basic algorithm is:
 *
 * 1) Bump link count on source while we're linking it to the
 *    target.  This also ensure the inode won't be deleted out
 *    from underneath us while we work (it may be truncated by
 *    a concurrent `trunc' or `open' for creation).
 * 2) Link source to destination.  If destination already exists,
 *    delete it first.
 * 3) Unlink source reference to inode if still around. If a
 *    directory was moved and the parent of the destination
 *    is different from the source, patch the ".." entry in the
 *    directory.
 *
 * ufs_rename(struct vnode *a_fdvp, struct vnode *a_fvp,
 *            struct componentname *a_fcnp, struct vnode *a_tdvp,
 *            struct vnode *a_tvp, struct componentname *a_tcnp)
 */
static
int
ufs_rename(struct vop_old_rename_args *ap)
{
        struct vnode *tvp = ap->a_tvp;
        struct vnode *tdvp = ap->a_tdvp;
        struct vnode *fvp = ap->a_fvp;
        struct vnode *fdvp = ap->a_fdvp;
        struct componentname *tcnp = ap->a_tcnp;
        struct componentname *fcnp = ap->a_fcnp;
        struct inode *ip, *xp, *dp;
        struct direct newdir;
        ino_t oldparent = 0, newparent = 0;
        int doingdirectory = 0;
        int error = 0, ioflag;

        /*
         * Check for cross-device rename.
         */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
abortit:
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                vrele(fdvp);
                vrele(fvp);
                return (error);
        }

#if 0   /* handled by kernel now */
        if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
            (VTOI(tdvp)->i_flags & APPEND))) {
                error = EPERM;
                goto abortit;
        }
#endif

        /*
         * Renaming a file to itself has no effect.  The upper layers should
         * not call us in that case.  Temporarily just warn if they do.
         */
        if (fvp == tvp) {
                kprintf("ufs_rename: fvp == tvp (can't happen)\n");
                error = 0;
                goto abortit;
        }

        error = vn_lock(fvp, LK_EXCLUSIVE | LK_FAILRECLAIM);
        if (error)
                goto abortit;

        /*
         * Note: now that fvp is locked we have to be sure to unlock it before
         * using the 'abortit' target.
         */
        dp = VTOI(fdvp);
        ip = VTOI(fvp);
        if (ip->i_nlink >= LINK_MAX) {
                vn_unlock(fvp);
                error = EMLINK;
                goto abortit;
        }
#if 0   /* handled by kernel now */
        if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
            || (dp->i_flags & APPEND)) {
                vn_unlock(fvp);
                error = EPERM;
                goto abortit;
        }
#endif
        if ((ip->i_mode & IFMT) == IFDIR) {
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
                    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & CNP_ISDOTDOT ||
                    (ip->i_flag & IN_RENAME)) {
                        vn_unlock(fvp);
                        error = EINVAL;
                        goto abortit;
                }
                ip->i_flag |= IN_RENAME;
                oldparent = dp->i_number;
                doingdirectory = 1;
        }
        VN_KNOTE(fdvp, NOTE_WRITE);             /* XXX right place? */

        /*
         * fvp still locked.  ip->i_flag has IN_RENAME set if doingdirectory.
         * Cleanup fvp requirements so we can unlock it.
         *
         * tvp and tdvp are locked.  tvp may be NULL.  Now that dp and xp
         * is setup we can use the 'bad' target if we unlock fvp.  We cannot
         * use the abortit target anymore because of IN_RENAME.
         */
        dp = VTOI(tdvp);
        if (tvp)
                xp = VTOI(tvp);
        else
                xp = NULL;

        /*
         * 1) Bump link count while we're moving stuff
         *    around.  If we crash somewhere before
         *    completing our work, the link count
         *    may be wrong, but correctable.
         */
        ip->i_effnlink++;
        ip->i_nlink++;
        ip->i_flag |= IN_CHANGE;
        if (DOINGSOFTDEP(fvp))
                softdep_change_linkcnt(ip);
        if ((error = ffs_update(fvp, !(DOINGSOFTDEP(fvp) |
                                       DOINGASYNC(fvp)))) != 0) {
                vn_unlock(fvp);
                goto bad;
        }

        /*
         * If ".." must be changed (ie the directory gets a new
         * parent) then the source directory must not be in the
         * directory heirarchy above the target, as this would
         * orphan everything below the source directory. Also
         * the user must have write permission in the source so
         * as to be able to change "..". We must repeat the call
         * to namei, as the parent directory is unlocked by the
         * call to checkpath().
         */
        error = VOP_EACCESS(fvp, VWRITE, tcnp->cn_cred);
        vn_unlock(fvp);

        /*
         * We are now back to where we were in that fvp, fdvp are unlocked
         * and tvp, tdvp are locked.  tvp may be NULL.  IN_RENAME may be
         * set.  Only the bad target or, if we clean up tvp and tdvp, the
         * out target, may be used.
         */
        if (oldparent != dp->i_number)
                newparent = dp->i_number;
        if (doingdirectory && newparent) {
                if (error)      /* write access check above */
                        goto bad;

                /*
                 * Once we start messing with tvp and tdvp we cannot use the
                 * 'bad' target, only finish cleaning tdvp and tvp up and
                 * use the 'out' target.
                 *
                 * This cleans up tvp.
                 */
                if (xp != NULL) {
                        vput(tvp);
                        xp = NULL;
                }

                /*
                 * This is a real mess. ufs_checkpath vput's the target
                 * directory so retain an extra ref and note that tdvp will
                 * lose its lock on return.  This leaves us with one good
                 * ref after ufs_checkpath returns.
                 */
                vref(tdvp);
                error = ufs_checkpath(ip, dp, tcnp->cn_cred);
                tcnp->cn_flags |= CNP_PDIRUNLOCK;
                if (error) {
                        vrele(tdvp);
                        goto out;
                }

                /*
                 * relookup no longer messes with tdvp's refs. tdvp must be
                 * unlocked on entry and will be locked on a successful
                 * return.
                 */
                error = relookup(tdvp, &tvp, tcnp);
                if (error) {
                        if (tcnp->cn_flags & CNP_PDIRUNLOCK)
                                vrele(tdvp);
                        else
                                vput(tdvp);
                        goto out;
                }
                KKASSERT((tcnp->cn_flags & CNP_PDIRUNLOCK) == 0);
                dp = VTOI(tdvp);
                if (tvp)
                        xp = VTOI(tvp);
        }

        /*
         * We are back to fvp, fdvp unlocked, tvp, tdvp locked.  tvp may 
         * be NULL (xp will also be NULL in that case), and IN_RENAME will
         * be set if doingdirectory.  This means we can use the 'bad' target
         * again.
         */

        /*
         * 2) If target doesn't exist, link the target
         *    to the source and unlink the source.
         *    Otherwise, rewrite the target directory
         *    entry to reference the source inode and
         *    expunge the original entry's existence.
         */
        if (xp == NULL) {
                if (dp->i_dev != ip->i_dev)
                        panic("ufs_rename: EXDEV");
                /*
                 * Account for ".." in new directory.
                 * When source and destination have the same
                 * parent we don't fool with the link count.
                 */
                if (doingdirectory && newparent) {
                        if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                                error = EMLINK;
                                goto bad;
                        }
                        dp->i_effnlink++;
                        dp->i_nlink++;
                        dp->i_flag |= IN_CHANGE;
                        if (DOINGSOFTDEP(tdvp))
                                softdep_change_linkcnt(dp);
                        error = ffs_update(tdvp, !(DOINGSOFTDEP(tdvp) |
                                                   DOINGASYNC(tdvp)));
                        if (error)
                                goto bad;
                }
                ufs_makedirentry(ip, tcnp, &newdir);
                error = ufs_direnter(tdvp, NULL, &newdir, tcnp, NULL);
                if (error) {
                        if (doingdirectory && newparent) {
                                dp->i_effnlink--;
                                dp->i_nlink--;
                                dp->i_flag |= IN_CHANGE;
                                if (DOINGSOFTDEP(tdvp))
                                        softdep_change_linkcnt(dp);
                                (void)ffs_update(tdvp, 1);
                        }
                        goto bad;
                }
                VN_KNOTE(tdvp, NOTE_WRITE);
                vput(tdvp);
        } else {
                if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
                        panic("ufs_rename: EXDEV");
                /*
                 * Short circuit rename(foo, foo).
                 */
                if (xp->i_number == ip->i_number)
                        panic("ufs_rename: same file");
                /*
                 * If the parent directory is "sticky", then the user must
                 * own the parent directory, or the destination of the rename,
                 * otherwise the destination may not be changed (except by
                 * root). This implements append-only directories.
                 */
                if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
                    tcnp->cn_cred->cr_uid != dp->i_uid &&
                    xp->i_uid != tcnp->cn_cred->cr_uid) {
                        error = EPERM;
                        goto bad;
                }
                /*
                 * Target must be empty if a directory and have no links
                 * to it. Also, ensure source and target are compatible
                 * (both directories, or both not directories).
                 *
                 * Purge the file or directory being replaced from the
                 * nameccache.
                 */
                if ((xp->i_mode&IFMT) == IFDIR) {
                        if ((xp->i_effnlink > 2) ||
                            !ufs_dirempty(xp, dp->i_number, tcnp->cn_cred)) {
                                error = ENOTEMPTY;
                                goto bad;
                        }
                        if (!doingdirectory) {
                                error = ENOTDIR;
                                goto bad;
                        }
                        /* cache_purge removed - handled by VFS compat layer */
                } else if (doingdirectory == 0) {
                        /* cache_purge removed - handled by VFS compat layer */
                } else {
                        error = EISDIR;
                        goto bad;
                }
                /*
                 * note: inode passed to ufs_dirrewrite() is 0 for a 
                 * non-directory file rename, 1 for a directory rename
                 * in the same directory, and > 1 for an inode representing
                 * the new directory.
                 */
                error = ufs_dirrewrite(dp, xp, ip->i_number,
                    IFTODT(ip->i_mode),
                    (doingdirectory && newparent) ?
                        newparent : (ino_t)doingdirectory);
                if (error)
                        goto bad;
                if (doingdirectory) {
                        if (!newparent) {
                                dp->i_effnlink--;
                                if (DOINGSOFTDEP(tdvp))
                                        softdep_change_linkcnt(dp);
                        }
                        xp->i_effnlink--;
                        if (DOINGSOFTDEP(tvp))
                                softdep_change_linkcnt(xp);
                }
                if (doingdirectory && !DOINGSOFTDEP(tvp)) {
                        /*
                         * Truncate inode. The only stuff left in the directory
                         * is "." and "..". The "." reference is inconsequential
                         * since we are quashing it. We have removed the "."
                         * reference and the reference in the parent directory,
                         * but there may be other hard links. The soft
                         * dependency code will arrange to do these operations
                         * after the parent directory entry has been deleted on
                         * disk, so when running with that code we avoid doing
                         * them now.
                         */
                        if (!newparent) {
                                dp->i_nlink--;
                                dp->i_flag |= IN_CHANGE;
                        }
                        xp->i_nlink--;
                        xp->i_flag |= IN_CHANGE;
                        ioflag = DOINGASYNC(tvp) ? 0 : IO_SYNC;
                        error = ffs_truncate(tvp, (off_t)0, ioflag,
                                             tcnp->cn_cred);
                        if (error)
                                goto bad;
                }
                VN_KNOTE(tdvp, NOTE_WRITE);
                vput(tdvp);
                VN_KNOTE(tvp, NOTE_DELETE);
                vput(tvp);
                xp = NULL;
        }

        /*
         * tvp and tdvp have been cleaned up.  only fvp and fdvp (both
         * unlocked) remain.  We are about to overwrite fvp but we have to
         * keep 'ip' intact so we cannot release the old fvp, which is still
         * refd and accessible via ap->a_fvp.
         *
         * This means we cannot use either 'bad' or 'out' to cleanup any 
         * more.
         */

        /*
         * 3) Unlink the source.
         */
        fcnp->cn_flags &= ~CNP_MODMASK;
        fcnp->cn_flags |= CNP_LOCKPARENT;
        error = relookup(fdvp, &fvp, fcnp);
        if (error || fvp == NULL) {
                /*
                 * From name has disappeared.  IN_RENAME will not be set if
                 * we get past the panic so we don't have to clean it up.
                 */
                if (doingdirectory)
                        panic("ufs_rename: lost dir entry");
                vrele(ap->a_fvp);
                if (fcnp->cn_flags & CNP_PDIRUNLOCK)
                        vrele(fdvp);
                else
                        vput(fdvp);
                return(0);
        }
        KKASSERT((fcnp->cn_flags & CNP_PDIRUNLOCK) == 0);

        /*
         * fdvp and fvp are locked.
         */
        xp = VTOI(fvp);
        dp = VTOI(fdvp);

        /*
         * Ensure that the directory entry still exists and has not
         * changed while the new name has been entered. If the source is
         * a file then the entry may have been unlinked or renamed. In
         * either case there is no further work to be done. If the source
         * is a directory then it cannot have been rmdir'ed; the IN_RENAME
         * flag ensures that it cannot be moved by another rename or removed
         * by a rmdir.  Cleanup IN_RENAME.
         */
        if (xp != ip) {
                if (doingdirectory)
                        panic("ufs_rename: lost dir entry");
        } else {
                /*
                 * If the source is a directory with a
                 * new parent, the link count of the old
                 * parent directory must be decremented
                 * and ".." set to point to the new parent.
                 */
                if (doingdirectory && newparent) {
                        xp->i_offset = mastertemplate.dot_reclen;
                        ufs_dirrewrite(xp, dp, newparent, DT_DIR, 0);
                        /* cache_purge removed - handled by VFS compat layer */
                }
                error = ufs_dirremove(fdvp, xp, fcnp->cn_flags, 0);
                xp->i_flag &= ~IN_RENAME;
        }

        VN_KNOTE(fvp, NOTE_RENAME);
        vput(fdvp);
        vput(fvp);
        vrele(ap->a_fvp);
        return (error);

bad:
        if (xp)
                vput(ITOV(xp));
        vput(ITOV(dp));
out:
        if (doingdirectory)
                ip->i_flag &= ~IN_RENAME;
        if (vn_lock(fvp, LK_EXCLUSIVE | LK_FAILRECLAIM) == 0) {
                ip->i_effnlink--;
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                ip->i_flag &= ~IN_RENAME;
                if (DOINGSOFTDEP(fvp))
                        softdep_change_linkcnt(ip);
                vput(fvp);
        } else {
                vrele(fvp);
        }
        return (error);
}

/*
 * Mkdir system call
 *
 * ufs_mkdir(struct vnode *a_dvp, struct vnode **a_vpp,
 *           struct componentname *a_cnp, struct vattr *a_vap)
 */
static
int
ufs_mkdir(struct vop_old_mkdir_args *ap)
{
        struct vnode *dvp = ap->a_dvp;
        struct vattr *vap = ap->a_vap;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip, *dp;
        struct vnode *tvp;
        struct buf *bp;
        struct dirtemplate dirtemplate, *dtp;
        struct direct newdir;
        int error, dmode;
        long blkoff;

        dp = VTOI(dvp);
        if ((nlink_t)dp->i_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out;
        }
        dmode = vap->va_mode & 0777;
        dmode |= IFDIR;
        /*
         * Must simulate part of ufs_makeinode here to acquire the inode,
         * but not have it entered in the parent directory. The entry is
         * made later after writing "." and ".." entries.
         */
        error = ffs_valloc(dvp, dmode, cnp->cn_cred, &tvp);
        if (error)
                goto out;
        ip = VTOI(tvp);
        ip->i_gid = dp->i_gid;
#ifdef SUIDDIR
        {
#ifdef QUOTA
                struct ucred ucred, *ucp;
                ucp = cnp->cn_cred;
#endif
                /*
                 * If we are hacking owners here, (only do this where told to)
                 * and we are not giving it TO root, (would subvert quotas)
                 * then go ahead and give it to the other user.
                 * The new directory also inherits the SUID bit.
                 * If user's UID and dir UID are the same,
                 * 'give it away' so that the SUID is still forced on.
                 */
                if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
                    (dp->i_mode & ISUID) && dp->i_uid) {
                        dmode |= ISUID;
                        ip->i_uid = dp->i_uid;
#ifdef QUOTA
                        if (dp->i_uid != cnp->cn_cred->cr_uid) {
                                /*
                                 * Make sure the correct user gets charged
                                 * for the space.
                                 * Make a dummy credential for the victim.
                                 * XXX This seems to never be accessed out of
                                 * our context so a stack variable is ok.
                                 */
                                ucred.cr_ref = 1;
                                ucred.cr_uid = ip->i_uid;
                                ucred.cr_ngroups = 1;
                                ucred.cr_groups[0] = dp->i_gid;
                                ucp = &ucred;
                        }
#endif
                } else
                        ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
                if ((error = ufs_getinoquota(ip)) ||
                    (error = ufs_chkiq(ip, 1, ucp, 0))) {
                        ffs_vfree(tvp, ip->i_number, dmode);
                        vput(tvp);
                        return (error);
                }
#endif
        }
#else   /* !SUIDDIR */
        ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
        if ((error = ufs_getinoquota(ip)) ||
            (error = ufs_chkiq(ip, 1, cnp->cn_cred, 0))) {
                ffs_vfree(tvp, ip->i_number, dmode);
                vput(tvp);
                return (error);
        }
#endif
#endif  /* !SUIDDIR */
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = dmode;
        tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
        ip->i_effnlink = 2;
        ip->i_nlink = 2;
        if (DOINGSOFTDEP(tvp))
                softdep_change_linkcnt(ip);
        if (cnp->cn_flags & CNP_ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;

        /*
         * Bump link count in parent directory to reflect work done below.
         * Should be done before reference is created so cleanup is
         * possible if we crash.
         */
        dp->i_effnlink++;
        dp->i_nlink++;
        dp->i_flag |= IN_CHANGE;
        if (DOINGSOFTDEP(dvp))
                softdep_change_linkcnt(dp);
        error = ffs_update(tvp, !(DOINGSOFTDEP(dvp) | DOINGASYNC(dvp)));
        if (error)
                goto bad;

        /*
         * The vnode must have a VM object in order to issue buffer cache
         * ops on it.
         */
        vinitvmio(tvp, DIRBLKSIZ, DIRBLKSIZ, -1);

        /*
         * Initialize directory with "." and ".." from static template.
         */
        if (dvp->v_mount->mnt_maxsymlinklen > 0)
                dtp = &mastertemplate;
        else
                dtp = (struct dirtemplate *)&omastertemplate;
        dirtemplate = *dtp;
        dirtemplate.dot_ino = ip->i_number;
        dirtemplate.dotdot_ino = dp->i_number;
        nvnode_pager_setsize(tvp, DIRBLKSIZ, DIRBLKSIZ, -1);
        error = VOP_BALLOC(tvp, 0LL, DIRBLKSIZ, cnp->cn_cred, B_CLRBUF, &bp);
        if (error)
                goto bad;
        ip->i_size = DIRBLKSIZ;
        ip->i_flag |= IN_CHANGE | IN_UPDATE;
        bcopy((caddr_t)&dirtemplate, (caddr_t)bp->b_data, sizeof dirtemplate);
        if (DOINGSOFTDEP(tvp)) {
                /*
                 * Ensure that the entire newly allocated block is a
                 * valid directory so that future growth within the
                 * block does not have to ensure that the block is
                 * written before the inode.
                 */
                blkoff = DIRBLKSIZ;
                while (blkoff < bp->b_bcount) {
                        ((struct direct *)
                           (bp->b_data + blkoff))->d_reclen = DIRBLKSIZ;
                        blkoff += DIRBLKSIZ;
                }
        }
        if ((error = ffs_update(tvp, !(DOINGSOFTDEP(tvp) |
                                       DOINGASYNC(tvp)))) != 0) {
                bwrite(bp);
                goto bad;
        }
        /*
         * Directory set up, now install its entry in the parent directory.
         *
         * If we are not doing soft dependencies, then we must write out the
         * buffer containing the new directory body before entering the new 
         * name in the parent. If we are doing soft dependencies, then the
         * buffer containing the new directory body will be passed to and
         * released in the soft dependency code after the code has attached
         * an appropriate ordering dependency to the buffer which ensures that
         * the buffer is written before the new name is written in the parent.
         */
        if (DOINGASYNC(dvp))
                bdwrite(bp);
        else if (!DOINGSOFTDEP(dvp) && (error = bwrite(bp)) != 0)
                goto bad;
        ufs_makedirentry(ip, cnp, &newdir);
        error = ufs_direnter(dvp, tvp, &newdir, cnp, bp);
        
bad:
        if (error == 0) {
                VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
                *ap->a_vpp = tvp;
        } else {
                dp->i_effnlink--;
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
                if (DOINGSOFTDEP(dvp))
                        softdep_change_linkcnt(dp);
                /*
                 * No need to do an explicit VOP_TRUNCATE here, vrele will
                 * do this for us because we set the link count to 0.
                 */
                ip->i_effnlink = 0;
                ip->i_nlink = 0;
                ip->i_flag |= IN_CHANGE;
                if (DOINGSOFTDEP(tvp))
                        softdep_change_linkcnt(ip);
                vput(tvp);
        }
out:
        return (error);
}

/*
 * Rmdir system call.
 *
 * ufs_rmdir(struct vnode *a_dvp, struct vnode *a_vp,
 *           struct componentname *a_cnp)
 */
static
int
ufs_rmdir(struct vop_old_rmdir_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip, *dp;
        int error, ioflag;

        ip = VTOI(vp);
        dp = VTOI(dvp);

        /*
         * Do not remove a directory that is in the process of being renamed.
         * Verify the directory is empty (and valid). Rmdir ".." will not be
         * valid since ".." will contain a reference to the current directory
         * and thus be non-empty. Do not allow the removal of mounted on
         * directories (this can happen when an NFS exported filesystem
         * tries to remove a locally mounted on directory).
         */
        error = 0;
        if (ip->i_flag & IN_RENAME) {
                error = EINVAL;
                goto out;
        }
        if (ip->i_effnlink != 2 ||
            !ufs_dirempty(ip, dp->i_number, cnp->cn_cred)) {
                error = ENOTEMPTY;
                goto out;
        }
#if 0   /* handled by kernel now */
        if ((dp->i_flags & APPEND)
            || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
                error = EPERM;
                goto out;
        }
#endif
        /*
         * Delete reference to directory before purging
         * inode.  If we crash in between, the directory
         * will be reattached to lost+found,
         */
        dp->i_effnlink--;
        ip->i_effnlink--;
        if (DOINGSOFTDEP(vp)) {
                softdep_change_linkcnt(dp);
                softdep_change_linkcnt(ip);
        }
        error = ufs_dirremove(dvp, ip, cnp->cn_flags, 1);
        if (error) {
                dp->i_effnlink++;
                ip->i_effnlink++;
                if (DOINGSOFTDEP(vp)) {
                        softdep_change_linkcnt(dp);
                        softdep_change_linkcnt(ip);
                }
                goto out;
        }
        VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
        /*
         * Truncate inode. The only stuff left in the directory is "." and
         * "..". The "." reference is inconsequential since we are quashing
         * it. The soft dependency code will arrange to do these operations
         * after the parent directory entry has been deleted on disk, so
         * when running with that code we avoid doing them now.
         */
        if (!DOINGSOFTDEP(vp)) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                ioflag = DOINGASYNC(vp) ? 0 : IO_SYNC;
                error = ffs_truncate(vp, (off_t)0, ioflag, cnp->cn_cred);
        }
        /* cache_purge removed - handled by VFS compat layer */
#ifdef UFS_DIRHASH
        /* Kill any active hash; i_effnlink == 0, so it will not come back. */
        if (ip->i_dirhash != NULL)
                ufsdirhash_free(ip);
#endif
out:
        VN_KNOTE(vp, NOTE_DELETE);
        return (error);
}

/*
 * symlink -- make a symbolic link
 *
 * ufs_symlink(struct vnode *a_dvp, struct vnode **a_vpp,
 *              struct componentname *a_cnp, struct vattr *a_vap,
 *              char *a_target)
 */
static
int
ufs_symlink(struct vop_old_symlink_args *ap)
{
        struct vnode *vp, **vpp = ap->a_vpp;
        struct inode *ip;
        int len, error;

        error = ufs_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
                              vpp, ap->a_cnp);
        if (error)
                return (error);
        VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        vp = *vpp;
        len = strlen(ap->a_target);
        if (len < vp->v_mount->mnt_maxsymlinklen) {
                ip = VTOI(vp);
                bcopy(ap->a_target, (char *)ip->i_shortlink, len);
                ip->i_size = len;
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
        } else {
                /*
                 * Make sure we have a VM object in order to use
                 * the buffer cache.
                 */
                if (vp->v_object == NULL)
                        vinitvmio(vp, 0, PAGE_SIZE, -1);
                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                                UIO_SYSSPACE, IO_NODELOCKED, 
                                ap->a_cnp->cn_cred, NULL);
        }
        if (error)
                vput(vp);
        return (error);
}

/*
 * Vnode op for reading directories.
 *
 * ufs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred,
 *              int *a_eofflag, int *ncookies, off_t **a_cookies)
 */
static
int
ufs_readdir(struct vop_readdir_args *ap)
{
        struct uio *uio = ap->a_uio;
        struct vnode *vp = ap->a_vp;
        struct direct *dp;
        struct buf *bp;
        int retval;
        int error;
        int offset;     /* offset into buffer cache buffer */
        int eoffset;    /* end of buffer clipped to file EOF */
        int pickup;     /* pickup point */
        int ncookies;
        int cookie_index;
        off_t *cookies;

        if (uio->uio_offset < 0)
                return (EINVAL);
        /*
         * Guess the number of cookies needed.  Make sure we compute at
         * least 1, and no more then a reasonable limit.
         */
        if (ap->a_ncookies) {
                ncookies = uio->uio_resid / 16 + 1;
                if (ncookies > 1024)
                        ncookies = 1024;
                cookies = kmalloc(ncookies * sizeof(off_t), M_TEMP, M_WAITOK);
        } else {
                ncookies = -1;  /* force conditionals below */
                cookies = NULL;
        }
        cookie_index = 0;

        error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM);
        if (error)
                return (error);

        /*
         * Past or at EOF
         */
        if (uio->uio_offset >= VTOI(vp)->i_size) {
                if (ap->a_eofflag)
                        *ap->a_eofflag = 1;
                if (ap->a_ncookies) {
                        *ap->a_ncookies = cookie_index;
                        *ap->a_cookies = cookies;
                }
                goto done;
        }

        /*
         * Loop until we run out of cookies, we run out of user buffer,
         * or we hit the directory EOF.
         *
         * Always start scans at the beginning of the buffer, don't trust
         * the offset supplied by userland.
         */
        while ((error = ffs_blkatoff_ra(vp, uio->uio_offset, NULL, &bp, 2)) == 0) {
                pickup = (int)(uio->uio_offset - bp->b_loffset);
                offset = 0;
                retval = 0;
                if (bp->b_loffset + bp->b_bcount > VTOI(vp)->i_size)
                        eoffset = (int)(VTOI(vp)->i_size - bp->b_loffset);
                else
                        eoffset = bp->b_bcount;

                while (offset < eoffset) {
                        dp = (struct direct *)(bp->b_data + offset);
                        if (dp->d_reclen <= 0 || (dp->d_reclen & 3) ||
                            offset + dp->d_reclen > bp->b_bcount) {
                                error = EIO;
                                break;
                        }
                        if (offsetof(struct direct, d_name[dp->d_namlen]) >                                  dp->d_reclen) {
                                error = EIO;
                                break;
                        }
                        if (offset < pickup) {
                                offset += dp->d_reclen;
                                continue;
                        }
#if BYTE_ORDER == LITTLE_ENDIAN
                        if (OFSFMT(vp)) {
                                retval = vop_write_dirent(&error, uio,
                                    dp->d_ino, dp->d_namlen, dp->d_type,
                                    dp->d_name);
                        } else
#endif
                        {
                                retval = vop_write_dirent(&error, uio,
                                    dp->d_ino, dp->d_type, dp->d_namlen,
                                    dp->d_name);
                        }
                        if (retval)
                                break;
                        if (cookies)
                                cookies[cookie_index] = bp->b_loffset + offset;
                        ++cookie_index;
                        offset += dp->d_reclen;
                        if (cookie_index == ncookies)
                                break;
                }

                /*
                 * This will align the next loop to the beginning of the
                 * next block, and pickup will calculate to 0.
                 */
                uio->uio_offset = bp->b_loffset + offset;
                brelse(bp);

                if (retval || error || cookie_index == ncookies ||
                    uio->uio_offset >= VTOI(vp)->i_size) {
                        break;
                }
        }
        if (ap->a_eofflag)
                *ap->a_eofflag = VTOI(vp)->i_size <= uio->uio_offset;

        /*
         * Report errors only if we didn't manage to read anything
         */
        if (error && cookie_index == 0) {
                if (cookies) {
                        kfree(cookies, M_TEMP);
                        *ap->a_ncookies = 0;
                        *ap->a_cookies = NULL;
                }
        } else {
                error = 0;
                if (cookies) {
                        *ap->a_ncookies = cookie_index;
                        *ap->a_cookies = cookies;
                }
        }
done:
        vn_unlock(vp);
        return (error);
}

/*
 * Return target name of a symbolic link
 *
 * ufs_readlink(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred)
 */
static
int
ufs_readlink(struct vop_readlink_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        int isize;

        isize = ip->i_size;
        if ((isize < vp->v_mount->mnt_maxsymlinklen) ||
            (ip->i_din.di_blocks == 0)) {   /* XXX - for old fastlink support */
                uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
                return (0);
        }

        /*
         * Perform the equivalent of an OPEN on vp so we can issue a
         * VOP_READ.
         */
        return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
}

/*
 * Calculate the logical to physical mapping if not done already,
 * then call the device strategy routine.
 *
 * In order to be able to swap to a file, the VOP_BMAP operation may not
 * deadlock on memory.  See ufs_bmap() for details.
 *
 * ufs_strategy(struct vnode *a_vp, struct bio *a_bio)
 */
static
int
ufs_strategy(struct vop_strategy_args *ap)
{
        struct bio *bio = ap->a_bio;
        struct bio *nbio;
        struct buf *bp = bio->bio_buf;
        struct vnode *vp = ap->a_vp;
        struct inode *ip;
        int error;

        ip = VTOI(vp);
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                panic("ufs_strategy: spec");
        nbio = push_bio(bio);
        if (nbio->bio_offset == NOOFFSET) {
                error = VOP_BMAP(vp, bio->bio_offset, &nbio->bio_offset,
                                 NULL, NULL, bp->b_cmd);
                if (error) {
                        bp->b_error = error;
                        bp->b_flags |= B_ERROR;
                        /* I/O was never started on nbio, must biodone(bio) */
                        biodone(bio);
                        return (error);
                }
                if (nbio->bio_offset == NOOFFSET)
                        vfs_bio_clrbuf(bp);
        }
        if (nbio->bio_offset == NOOFFSET) {
                /*
                 * We hit a hole in the file.  The buffer has been zero-filled
                 * so just biodone() it.
                 */
                biodone(bio);
        } else {
                vn_strategy(ip->i_devvp, nbio);
        }
        return (0);
}

/*
 * Print out the contents of an inode.
 *
 * ufs_print(struct vnode *a_vp)
 */
static
int
ufs_print(struct vop_print_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);

        kprintf("tag VT_UFS, ino %lu, on dev %s (%d, %d)",
            (u_long)ip->i_number, devtoname(ip->i_dev), major(ip->i_dev),
            minor(ip->i_dev));
        if (vp->v_type == VFIFO)
                fifo_printinfo(vp);
        lockmgr_printinfo(&vp->v_lock);
        kprintf("\n");
        return (0);
}

/*
 * Read wrapper for fifos.
 *
 * ufsfifo_read(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *              struct ucred *a_cred)
 */
static
int
ufsfifo_read(struct vop_read_args *ap)
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        ip = VTOI(ap->a_vp);
        if ((ap->a_vp->v_mount->mnt_flag & MNT_NOATIME) == 0 && ip != NULL &&
            (uio->uio_resid != resid || (error == 0 && resid != 0)))
                VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (error);
}

/*
 * Write wrapper for fifos.
 *
 * ufsfifo_write(struct vnode *a_vp, struct uio *a_uio, int a_ioflag,
 *               struct ucred *a_cred)
 */
static
int
ufsfifo_write(struct vop_write_args *ap)
{
        int error, resid;
        struct inode *ip;
        struct uio *uio;

        uio = ap->a_uio;
        resid = uio->uio_resid;
        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        ip = VTOI(ap->a_vp);
        if (ip != NULL && (uio->uio_resid != resid || (error == 0 && resid != 0)))
                VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (error);
}

/*
 * Close wrapper for fifos.
 *
 * Update the times on the inode then do device close.
 *
 * ufsfifo_close(struct vnode *a_vp, int a_fflag)
 */
static
int
ufsfifo_close(struct vop_close_args *ap)
{
        struct vnode *vp = ap->a_vp;

        if (VREFCNT(vp) > 1)
                ufs_itimes(vp);
        return (VOCALL(&fifo_vnode_vops, &ap->a_head));
}

/*
 * Return POSIX pathconf information applicable to ufs filesystems.
 */
static int
ufs_pathconf(struct vop_pathconf_args *ap)
{
        int error;

        error = 0;
        switch (ap->a_name) {
        case _PC_MIN_HOLE_SIZE:
                *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
                break;

        default:
                error = vop_stdpathconf(ap);
                break;
        }
        return (error);
}

/*
 * Kqfilter wrapper for fifos.
 *
 * Fall through to ufs kqfilter routines if needed 
 */
static
int
ufsfifo_kqfilter(struct vop_kqfilter_args *ap)
{
        int error;

        error = VOCALL(&fifo_vnode_vops, &ap->a_head);
        if (error)
                error = ufs_kqfilter(ap);
        return (error);
}

/*
 * Advisory record locking support
 *
 * ufs_advlock(struct vnode *a_vp, caddr_t a_id, int a_op, struct flock *a_fl,
 *             int a_flags)
 */
static
int
ufs_advlock(struct vop_advlock_args *ap)
{
        struct inode *ip = VTOI(ap->a_vp);

        return (lf_advlock(ap, &(ip->i_lockf), ip->i_size));
}

/*
 * Initialize the vnode associated with a new inode, handle aliased
 * vnodes.
 *
 * Make sure directories have their VM object now rather then later,
 * saving us from having to check on all the myrid directory VOPs
 * that might be executed without a VOP_OPEN being performed.
 */
int
ufs_vinit(struct mount *mntp, struct vnode **vpp)
{
        struct inode *ip;
        struct vnode *vp;

        vp = *vpp;
        ip = VTOI(vp);

        vp->v_type = IFTOVT(ip->i_mode);

        switch(vp->v_type) {
        case VCHR:
        case VBLK:
                vp->v_ops = &mntp->mnt_vn_spec_ops;
                addaliasu(vp, umajor(ip->i_rdev), uminor(ip->i_rdev));
                break;
        case VFIFO:
                vp->v_ops = &mntp->mnt_vn_fifo_ops;
                break;
        case VDIR:
        case VREG:
                vinitvmio(vp, ip->i_size,
                          blkoffsize(ip->i_fs, ip, ip->i_size),
                          blkoff(ip->i_fs, ip->i_size));
                break;
        case VLNK:
                if (ip->i_size >= vp->v_mount->mnt_maxsymlinklen) {
                        vinitvmio(vp, ip->i_size,
                                  blkoffsize(ip->i_fs, ip, ip->i_size),
                                  blkoff(ip->i_fs, ip->i_size));
                }
                break;
        default:
                break;

        }

        if (ip->i_number == UFS_ROOTINO)
                vsetflags(vp, VROOT);
        /*
         * Initialize modrev times
         */
        ip->i_modrev = init_va_filerev();
        *vpp = vp;
        return (0);
}

/*
 * Allocate a new inode.
 */
static
int
ufs_makeinode(int mode, struct vnode *dvp, struct vnode **vpp,
              struct componentname *cnp)
{
        struct inode *ip, *pdir;
        struct direct newdir;
        struct vnode *tvp;
        int error;

        pdir = VTOI(dvp);
        *vpp = NULL;
        if ((mode & IFMT) == 0)
                mode |= IFREG;

        error = ffs_valloc(dvp, mode, cnp->cn_cred, &tvp);
        if (error)
                return (error);
        ip = VTOI(tvp);
        ip->i_flags = pdir->i_flags & (SF_NOHISTORY|UF_NOHISTORY|UF_NODUMP);
        ip->i_gid = pdir->i_gid;
#ifdef SUIDDIR
        {
#ifdef QUOTA
                struct ucred ucred, *ucp;
                ucp = cnp->cn_cred;
#endif
                /*
                 * If we are not the owner of the directory,
                 * and we are hacking owners here, (only do this where told to)
                 * and we are not giving it TO root, (would subvert quotas)
                 * then go ahead and give it to the other user.
                 * Note that this drops off the execute bits for security.
                 */
                if ((dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
                    (pdir->i_mode & ISUID) &&
                    (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
                        ip->i_uid = pdir->i_uid;
                        mode &= ~07111;
#ifdef QUOTA
                        /*
                         * Make sure the correct user gets charged
                         * for the space.
                         * Quickly knock up a dummy credential for the victim.
                         * XXX This seems to never be accessed out of our
                         * context so a stack variable is ok.
                         */
                        ucred.cr_ref = 1;
                        ucred.cr_uid = ip->i_uid;
                        ucred.cr_ngroups = 1;
                        ucred.cr_groups[0] = pdir->i_gid;
                        ucp = &ucred;
#endif
                } else
                        ip->i_uid = cnp->cn_cred->cr_uid;

#ifdef QUOTA
                if ((error = ufs_getinoquota(ip)) ||
                    (error = ufs_chkiq(ip, 1, ucp, 0))) {
                        ffs_vfree(tvp, ip->i_number, mode);
                        vput(tvp);
                        return (error);
                }
#endif
        }
#else   /* !SUIDDIR */
        ip->i_uid = cnp->cn_cred->cr_uid;
#ifdef QUOTA
        if ((error = ufs_getinoquota(ip)) ||
            (error = ufs_chkiq(ip, 1, cnp->cn_cred, 0))) {
                ffs_vfree(tvp, ip->i_number, mode);
                vput(tvp);
                return (error);
        }
#endif
#endif  /* !SUIDDIR */
        ip->i_din.di_spare7E = 0;
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = mode;
        tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
        ip->i_effnlink = 1;
        ip->i_nlink = 1;
        if (DOINGSOFTDEP(tvp))
                softdep_change_linkcnt(ip);
        if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred) &&
            caps_priv_check(cnp->cn_cred, SYSCAP_NOVFS_SETGID))
        {
                ip->i_mode &= ~ISGID;
        }

        if (cnp->cn_flags & CNP_ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;

        /*
         * Regular files and directories need VM objects.  Softlinks do
         * not (not immediately anyway).
         */
        if (tvp->v_type == VREG || tvp->v_type == VDIR)
                vinitvmio(tvp, 0, PAGE_SIZE, -1);

        /*
         * Make sure inode goes to disk before directory entry.
         */
        error = ffs_update(tvp, !(DOINGSOFTDEP(tvp) | DOINGASYNC(tvp)));
        if (error)
                goto bad;
        ufs_makedirentry(ip, cnp, &newdir);
        error = ufs_direnter(dvp, tvp, &newdir, cnp, NULL);
        if (error)
                goto bad;
        *vpp = tvp;
        return (0);

bad:
        /*
         * Write error occurred trying to update the inode
         * or the directory so must deallocate the inode.
         */
        ip->i_effnlink = 0;
        ip->i_nlink = 0;
        ip->i_flag |= IN_CHANGE;
        if (DOINGSOFTDEP(tvp))
                softdep_change_linkcnt(ip);
        vput(tvp);
        return (error);
}

static int
ufs_ioctl(struct vop_ioctl_args *ap)
{

        switch (ap->a_command) {
        case FIOSEEKDATA:
        case FIOSEEKHOLE:
                return (vn_bmap_seekhole(ap->a_vp, ap->a_command,
                    (off_t *)ap->a_data, ap->a_cred));
        default:
                return (ENOTTY);
        }
}

static int
ufs_missingop(struct vop_generic_args *ap)
{
        panic("no vop function for %s in ufs child", ap->a_desc->sd_name);
        return (EOPNOTSUPP);
}

static struct filterops ufsread_filtops = 
        { FILTEROP_ISFD, NULL, filt_ufsdetach, filt_ufsread };
static struct filterops ufswrite_filtops = 
        { FILTEROP_ISFD, NULL, filt_ufsdetach, filt_ufswrite };
static struct filterops ufsvnode_filtops = 
        { FILTEROP_ISFD, NULL, filt_ufsdetach, filt_ufsvnode };

/*
 * ufs_kqfilter(struct vnode *a_vp, struct knote *a_kn)
 */
static int
ufs_kqfilter(struct vop_kqfilter_args *ap)
{
        struct vnode *vp = ap->a_vp;
        struct knote *kn = ap->a_kn;

        switch (kn->kn_filter) {
        case EVFILT_READ:
                kn->kn_fop = &ufsread_filtops;
                break;
        case EVFILT_WRITE:
                kn->kn_fop = &ufswrite_filtops;
                break;
        case EVFILT_VNODE:
                kn->kn_fop = &ufsvnode_filtops;
                break;
        default:
                return (EOPNOTSUPP);
        }

        kn->kn_hook = (caddr_t)vp;

        /* XXX: kq token actually protects the list */
        lwkt_gettoken(&vp->v_token);
        knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
        lwkt_reltoken(&vp->v_token);

        return (0);
}

static void
filt_ufsdetach(struct knote *kn)
{
        struct vnode *vp = (struct vnode *)kn->kn_hook;

        lwkt_gettoken(&vp->v_token);
        knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn);
        lwkt_reltoken(&vp->v_token);
}

/*ARGSUSED*/
static int
filt_ufsread(struct knote *kn, long hint)
{
        struct vnode *vp = (struct vnode *)kn->kn_hook;
        struct inode *ip = VTOI(vp);
        off_t off;

        /*
         * filesystem is gone, so set the EOF flag and schedule 
         * the knote for deletion.
         */
        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);
                return (1);
        }

        off = ip->i_size - kn->kn_fp->f_offset;
        kn->kn_data = (off < INTPTR_MAX) ? off : INTPTR_MAX;
        if (kn->kn_sfflags & NOTE_OLDAPI)
                return(1);
        return (kn->kn_data != 0);
}

/*ARGSUSED*/
static int
filt_ufswrite(struct knote *kn, long hint)
{
        /*
         * filesystem is gone, so set the EOF flag and schedule 
         * the knote for deletion.
         */
        if (hint == NOTE_REVOKE)
                kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT);

        kn->kn_data = 0;
        return (1);
}

static int
filt_ufsvnode(struct knote *kn, long hint)
{
        if (kn->kn_sfflags & hint)
                kn->kn_fflags |= hint;
        if (hint == NOTE_REVOKE) {
                kn->kn_flags |= (EV_EOF | EV_NODATA);
                return (1);
        }
        return (kn->kn_fflags != 0);
}

/* Global vfs data structures for ufs. */
static struct vop_ops ufs_vnode_vops = {
        .vop_default =          vop_defaultop,
        .vop_fsync =            (void *)ufs_missingop,
        .vop_read =             (void *)ufs_missingop,
        .vop_reallocblks =      (void *)ufs_missingop,
        .vop_write =            (void *)ufs_missingop,
        .vop_access =           ufs_access,
        .vop_advlock =          ufs_advlock,
        .vop_bmap =             ufs_bmap,
        .vop_old_lookup =       ufs_lookup,
        .vop_close =            ufs_close,
        .vop_old_create =       ufs_create,
        .vop_getattr =          ufs_getattr,
        .vop_inactive =         ufs_inactive,
        .vop_ioctl =            ufs_ioctl,
        .vop_old_link =         ufs_link,
        .vop_old_mkdir =        ufs_mkdir,
        .vop_old_mknod =        ufs_mknod,
        .vop_open =             vop_stdopen,
        .vop_pathconf =         ufs_pathconf,
        .vop_kqfilter =         ufs_kqfilter,
        .vop_print =            ufs_print,
        .vop_readdir =          ufs_readdir,
        .vop_readlink =         ufs_readlink,
        .vop_reclaim =          ufs_reclaim,
        .vop_old_remove =       ufs_remove,
        .vop_old_rename =       ufs_rename,
        .vop_old_rmdir =        ufs_rmdir,
        .vop_setattr =          ufs_setattr,
        .vop_markatime =        ufs_markatime,
        .vop_strategy =         ufs_strategy,
        .vop_old_symlink =      ufs_symlink,
        .vop_old_whiteout =     ufs_whiteout
};

static struct vop_ops ufs_spec_vops = {
        .vop_default =          vop_defaultop,
        .vop_fsync =            (void *)ufs_missingop,
        .vop_access =           ufs_access,
        .vop_close =            ufs_close,
        .vop_getattr =          ufs_getattr,
        .vop_inactive =         ufs_inactive,
        .vop_print =            ufs_print,
        .vop_read =             vop_stdnoread,
        .vop_reclaim =          ufs_reclaim,
        .vop_setattr =          ufs_setattr,
        .vop_markatime =        ufs_markatime,
        .vop_write =            vop_stdnowrite
};

static struct vop_ops ufs_fifo_vops = {
        .vop_default =          fifo_vnoperate,
        .vop_fsync =            (void *)ufs_missingop,
        .vop_access =           ufs_access,
        .vop_close =            ufsfifo_close,
        .vop_getattr =          ufs_getattr,
        .vop_inactive =         ufs_inactive,
        .vop_kqfilter =         ufsfifo_kqfilter,
        .vop_print =            ufs_print,
        .vop_read =             ufsfifo_read,
        .vop_reclaim =          ufs_reclaim,
        .vop_setattr =          ufs_setattr,
        .vop_markatime =        ufs_markatime,
        .vop_write =            ufsfifo_write
};

VNODEOP_SET(ufs_vnode_vops);
VNODEOP_SET(ufs_spec_vops);
VNODEOP_SET(ufs_fifo_vops);

/*
 * ufs_vnoperate()
 */
int
ufs_vnoperate(struct vop_generic_args *ap)
{
        return (VOCALL(&ufs_vnode_vops, ap));
}

/*
 * ufs_vnoperatefifo()
 */
int
ufs_vnoperatefifo(struct vop_generic_args *ap)
{
        return (VOCALL(&ufs_fifo_vops, ap));
}

/*
 * ufs_vnoperatespec()
 */
int
ufs_vnoperatespec(struct vop_generic_args *ap)
{
        return (VOCALL(&ufs_spec_vops, ap));
}