xnu-792.6.61.tar.gz

[apple/xnu.git] / bsd / ufs / ufs / ufs_vnops.c

/*
 * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
/*
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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
 */

#include <rev_endian_fs.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/file_internal.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <sys/conf.h>
#include <sys/mount_internal.h>
#include <sys/vnode_internal.h>
#include <sys/malloc.h>
#include <sys/dirent.h>
#include <sys/fcntl.h>
#include <sys/ubc.h>
#include <sys/quota.h>
#include <sys/uio_internal.h>

#include <kern/thread.h>
#include <sys/vm.h>

#include <miscfs/specfs/specdev.h>

#include <ufs/ufs/quota.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/dir.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/ufs_extern.h>

#if REV_ENDIAN_FS
#include <ufs/ufs/ufs_byte_order.h>
#include <architecture/byte_order.h>
#endif /* REV_ENDIAN_FS */


static int ufs_chmod(struct vnode *, int, kauth_cred_t, struct proc *);
static int ufs_chown(struct vnode *, uid_t, gid_t, kauth_cred_t,
                struct proc *);
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);

#if FIFO
extern void fifo_printinfo(struct vnode *vp);
#endif /* FIFO */
extern int ufs_direnter2(struct vnode *dvp, struct direct *dirp, 
                                  vfs_context_t ctx);

static int ufs_readdirext(vnode_t vp, uio_t uio, int *eofflag, int *numdirent,
                          vfs_context_t context);

/*
 * Create a regular file
 */
int
ufs_create(ap)
        struct vnop_create_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vnode_vattr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        int error;

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

/*
 * Mknod vnode call
 */
int
ufs_mknod(ap)
        struct vnop_mknod_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode_attr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct vnode *dvp = ap->a_dvp;
        struct vnode *tvp;
        struct inode *ip;
        struct componentname *cnp = ap->a_cnp;
        int error;

        /* use relookup to force correct directory hints */
        cnp->cn_flags &= ~MODMASK;
        cnp->cn_flags |= (WANTPARENT | NOCACHE);
        cnp->cn_nameiop = CREATE;

        (void) relookup(dvp, &tvp, cnp);

        /* get rid of reference relookup returned */
        if (tvp)
                vnode_put(tvp);

        if ( (error =
              ufs_makeinode(ap->a_vap, ap->a_dvp, vpp, ap->a_cnp)) )
                return (error);
        VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        ip = VTOI(*vpp);
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        if (vap->va_rdev != VNOVAL) {
                /*
                 * Want to be able to use this to make badblock
                 * inodes, so don't truncate the dev number.
                 */
                ip->i_rdev = vap->va_rdev;
        }
        return (0);
}

/*
 * Open called.
 *
 * Nothing to do.
 */
int
ufs_open(ap)
        struct vnop_open_args /* {
                struct vnode *a_vp;
                int  a_mode;
                vfs_context_t a_context;
        } */ *ap;
{

        /*
         * Files marked append-only must be opened for appending.
         */
        if ((VTOI(ap->a_vp)->i_flags & APPEND) &&
            (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                return (EPERM);
        return (0);
}

/*
 * Close called.
 *
 * Update the times on the inode.
 */
int
ufs_close(ap)
        struct vnop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        register struct inode *ip = VTOI(vp);
        struct timeval tv;

        if (vnode_isinuse(vp, 1)) {
                microtime(&tv);
                ITIMES(ip, &tv, &tv);
        }

        cluster_push(vp, IO_CLOSE);

        return (0);
}

int
ufs_getattr(ap)
        struct vnop_getattr_args /* {
                struct vnode *a_vp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        register struct inode *ip = VTOI(vp);
        register struct vnode_attr *vap = ap->a_vap;
        int devBlockSize=0;
        struct timeval tv;

        microtime(&tv);
  
        ITIMES(ip, &tv, &tv);
        /*
         * Copy from inode table
         */
        VATTR_RETURN(vap, va_fsid, ip->i_dev);
        VATTR_RETURN(vap, va_fileid, ip->i_number);
        VATTR_RETURN(vap, va_mode, ip->i_mode & ~IFMT);
        VATTR_RETURN(vap, va_nlink, ip->i_nlink);
        VATTR_RETURN(vap, va_uid, ip->i_uid);
        VATTR_RETURN(vap, va_gid, ip->i_gid);
        VATTR_RETURN(vap, va_rdev, (dev_t)ip->i_rdev);
        VATTR_RETURN(vap, va_data_size, ip->i_din.di_size);
        vap->va_access_time.tv_sec = ip->i_atime;
        vap->va_access_time.tv_nsec = ip->i_atimensec;
        VATTR_SET_SUPPORTED(vap, va_access_time);
        vap->va_modify_time.tv_sec = ip->i_mtime;
        vap->va_modify_time.tv_nsec = ip->i_mtimensec;
        VATTR_SET_SUPPORTED(vap, va_modify_time);
        vap->va_change_time.tv_sec = ip->i_ctime;
        vap->va_change_time.tv_nsec = ip->i_ctimensec;
        VATTR_SET_SUPPORTED(vap, va_change_time);
        VATTR_RETURN(vap, va_flags, ip->i_flags);
        VATTR_RETURN(vap, va_gen, ip->i_gen);
        if (vp->v_type == VBLK)
                VATTR_RETURN(vap, va_iosize, BLKDEV_IOSIZE);
        else if (vp->v_type == VCHR)
                VATTR_RETURN(vap, va_iosize, MAXPHYSIO);
        else
                VATTR_RETURN(vap, va_iosize, vp->v_mount->mnt_vfsstat.f_iosize);
        devBlockSize = vfs_devblocksize(vnode_mount(vp));
        VATTR_RETURN(vap, va_data_alloc, dbtob((u_quad_t)ip->i_blocks, devBlockSize));
        VATTR_RETURN(vap, va_type, vp->v_type);
        VATTR_RETURN(vap, va_filerev, ip->i_modrev);
        return (0);
}

/*
 * Set attribute vnode op. called from several syscalls
 */
int
ufs_setattr(ap)
        struct vnop_setattr_args /* {
                struct vnode *a_vp;
                struct vnode_attr *a_vap;
                struct proc *a_p;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode_attr *vap = ap->a_vap;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        kauth_cred_t cred = vfs_context_ucred(ap->a_context);
        struct proc *p = vfs_context_proc(ap->a_context);
        struct timeval atimeval, mtimeval;
        int error;
        uid_t nuid;
        gid_t ngid;

        /*
         * Go through the fields and update iff set.
         */
        if (VATTR_IS_ACTIVE(vap, va_flags)) {
                ip->i_flags = vap->va_flags;
                ip->i_flag |= IN_CHANGE;
        }
        VATTR_SET_SUPPORTED(vap, va_flags);

        nuid = VATTR_IS_ACTIVE(vap, va_uid) ? vap->va_uid : (uid_t)VNOVAL;
        ngid = VATTR_IS_ACTIVE(vap, va_gid) ? vap->va_gid : (gid_t)VNOVAL;
        if (nuid != (uid_t)VNOVAL || ngid != (gid_t)VNOVAL) {
                if ( (error = ufs_chown(vp, nuid, ngid, cred, p)) )
                        return (error);
        }
        VATTR_SET_SUPPORTED(vap, va_uid);
        VATTR_SET_SUPPORTED(vap, va_gid);

        if (VATTR_IS_ACTIVE(vap, va_data_size)) {
                if ( (error = ffs_truncate_internal(vp, vap->va_data_size, vap->va_vaflags & 0xffff, cred)) )
                        return (error);
        }
        VATTR_SET_SUPPORTED(vap, va_data_size);
        
        ip = VTOI(vp);
        if (VATTR_IS_ACTIVE(vap, va_access_time) || VATTR_IS_ACTIVE(vap, va_modify_time)) {
                if (VATTR_IS_ACTIVE(vap, va_access_time))
                        ip->i_flag |= IN_ACCESS;
                if (VATTR_IS_ACTIVE(vap, va_modify_time))
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                atimeval.tv_sec = vap->va_access_time.tv_sec;
                atimeval.tv_usec = vap->va_access_time.tv_nsec / 1000;
                mtimeval.tv_sec = vap->va_modify_time.tv_sec;
                mtimeval.tv_usec = vap->va_modify_time.tv_nsec / 1000;
                if ( (error = ffs_update(vp, &atimeval, &mtimeval, 1)) )
                        return (error);
        }
        VATTR_SET_SUPPORTED(vap, va_access_time);
        VATTR_SET_SUPPORTED(vap, va_modify_time);
        
        if (VATTR_IS_ACTIVE(vap, va_mode)) {
                if ((error = ufs_chmod(vp, (int)vap->va_mode, cred, p)))
                        return (error);
        }
        VATTR_SET_SUPPORTED(vap, va_mode);
        
        VN_KNOTE(vp, NOTE_ATTRIB);

        return (0);
}

/*
 * Change the mode on a file.
 * Inode must be locked before calling.
 */
static int
ufs_chmod(struct vnode *vp, int mode, kauth_cred_t cred, struct proc *p)
{
        register struct inode *ip = VTOI(vp);

        ip->i_mode &= ~ALLPERMS;
        ip->i_mode |= (mode & ALLPERMS);
        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, kauth_cred_t cred,
        struct proc *p)
{
        register struct inode *ip = VTOI(vp);
        uid_t ouid;
        gid_t ogid;
        int error = 0;
        int is_member;
#if QUOTA
        register int i;
        int64_t change;   /* in bytes */
        int devBlockSize=0;
#endif /* QUOTA */

        if (uid == (uid_t)VNOVAL)
                uid = ip->i_uid;
        if (gid == (gid_t)VNOVAL)
                gid = ip->i_gid;
        ogid = ip->i_gid;
        ouid = ip->i_uid;
#if QUOTA
        if ( (error = getinoquota(ip)) )
                return (error);
        if (ouid == uid) {
                dqrele(ip->i_dquot[USRQUOTA]);
                ip->i_dquot[USRQUOTA] = NODQUOT;
        }
        if (ogid == gid) {
                dqrele(ip->i_dquot[GRPQUOTA]);
                ip->i_dquot[GRPQUOTA] = NODQUOT;
        }
        devBlockSize = vfs_devblocksize(vnode_mount(vp));

        change = dbtob((int64_t)ip->i_blocks, devBlockSize);
        (void) chkdq(ip, -change, cred, CHOWN);
        (void) chkiq(ip, -1, cred, CHOWN);
        for (i = 0; i < MAXQUOTAS; i++) {
                dqrele(ip->i_dquot[i]);
                ip->i_dquot[i] = NODQUOT;
        }
#endif
        ip->i_gid = gid;
        ip->i_uid = uid;
#if QUOTA
        if ((error = getinoquota(ip)) == 0) {
                if (ouid == uid) {
                        dqrele(ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        dqrele(ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                if ((error = chkdq(ip, change, cred, CHOWN)) == 0) {
                        if ((error = chkiq(ip, 1, cred, CHOWN)) == 0)
                                goto good;
                        else
                                (void) chkdq(ip, -change, cred, CHOWN|FORCE);
                }
                for (i = 0; i < MAXQUOTAS; i++) {
                        dqrele(ip->i_dquot[i]);
                        ip->i_dquot[i] = NODQUOT;
                }
        }
        ip->i_gid = ogid;
        ip->i_uid = ouid;
        if (getinoquota(ip) == 0) {
                if (ouid == uid) {
                        dqrele(ip->i_dquot[USRQUOTA]);
                        ip->i_dquot[USRQUOTA] = NODQUOT;
                }
                if (ogid == gid) {
                        dqrele(ip->i_dquot[GRPQUOTA]);
                        ip->i_dquot[GRPQUOTA] = NODQUOT;
                }
                (void) chkdq(ip, change, cred, FORCE|CHOWN);
                (void) chkiq(ip, 1, cred, FORCE|CHOWN);
                (void) getinoquota(ip);
        }
        return (error);
good:
        if (getinoquota(ip))
                panic("chown: lost quota");
#endif /* QUOTA */
        if (ouid != uid || ogid != gid)
                ip->i_flag |= IN_CHANGE;
        return (0);
}

int
ufs_ioctl(ap)
        struct vnop_ioctl_args /* {
                struct vnode *a_vp;
                int  a_command;
                caddr_t  a_data;
                int  a_fflag;
                vfs_context_t a_context;
        } */ *ap;
{

        switch (ap->a_command) {
        
        case 1:
        {       register struct inode *ip;
                register struct vnode *vp;
                register struct fs *fs;
                register struct radvisory *ra;
                int devBlockSize = 0;
                int error;

                vp = ap->a_vp;

                ra = (struct radvisory *)(ap->a_data);
                ip = VTOI(vp);
                fs = ip->i_fs;

                if ((u_int64_t)ra->ra_offset >= ip->i_size) {
                        return (EFBIG);
                }
                devBlockSize = vfs_devblocksize(vnode_mount(vp));

                error = advisory_read(vp, ip->i_size, ra->ra_offset, ra->ra_count);

                return (error);
        }
        default:
                return (ENOTTY);
        }
}

int
ufs_select(__unused struct vnop_select_args *ap)
{
        /*
         * We should really check to see if I/O is possible.
         */
        return (1);
}

/*
 * Mmap a file
 *
 * NB Currently unsupported.
 */
int
ufs_mmap(__unused struct vnop_mmap_args *ap)
{
        return (EINVAL);
}

int
ufs_remove(ap)
        struct vnop_remove_args /* {
                struct vnode *a_dvp;
                struct vnode *a_vp;
                struct componentname *a_cnp;
                int *a_flags;
                vfs_context_t a_context;
        } */ *ap;
{
        return(ufs_remove_internal(ap->a_dvp, ap->a_vp, ap->a_cnp, ap->a_flags));
}


int
ufs_remove_internal(vnode_t dvp, vnode_t vp, struct componentname *cnp, int flags)
{
        struct inode *ip;
        struct vnode *tvp;
        int error;

        if (flags & VNODE_REMOVE_NODELETEBUSY) {
                /* Caller requested Carbon delete semantics */
                if (vnode_isinuse(vp, 0)) {
                        error = EBUSY;
                        goto out;
                }
        }
        cnp->cn_flags &= ~MODMASK;
        cnp->cn_flags |= (WANTPARENT | NOCACHE);
        cnp->cn_nameiop = DELETE;

        (void) relookup(dvp, &tvp, cnp);

        if (tvp == NULL)
                return (ENOENT);
        if (tvp != vp)
                panic("ufs_remove_internal: relookup returned a different vp");
        /*
         * get rid of reference relookup returned
         */
        vnode_put(tvp);


        ip = VTOI(vp);

        if ((error = ufs_dirremove(dvp, cnp)) == 0) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
                VN_KNOTE(vp, NOTE_DELETE);
                VN_KNOTE(dvp, NOTE_WRITE);
        }
out:
        return (error);
}

/*
 * link vnode call
 */
int
ufs_link(ap)
        struct vnop_link_args /* {
                struct vnode *a_vp;
                struct vnode *a_tdvp;
                struct componentname *a_cnp;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct vnode *tdvp = ap->a_tdvp;
        struct componentname *cnp = ap->a_cnp;
        vfs_context_t ctx = cnp->cn_context;
        struct proc *p = vfs_context_proc(ctx);
        struct inode *ip;
        struct timeval tv;
        int error;

        ip = VTOI(vp);

        if ((nlink_t)ip->i_nlink >= LINK_MAX) {
                error = EMLINK;
                goto out1;
        }
        ip->i_nlink++;
        ip->i_flag |= IN_CHANGE;
        microtime(&tv);
        error = ffs_update(vp, &tv, &tv, 1);
        if (!error)
                error = ufs_direnter(ip, tdvp, cnp);
        if (error) {
                ip->i_nlink--;
                ip->i_flag |= IN_CHANGE;
        }
        VN_KNOTE(vp, NOTE_LINK);
        VN_KNOTE(tdvp, NOTE_WRITE);
out1:
        return (error);
}

/*
 * whiteout vnode call
 */

int
ufs_whiteout(ap)
        struct vnop_whiteout_args /* {
                struct vnode *a_dvp;
                struct componentname *a_cnp;
                int a_flags;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *dvp = ap->a_dvp;
        struct componentname *cnp = ap->a_cnp;
        struct direct newdir;
        int error = 0;

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

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

                newdir.d_ino = 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_direnter2(dvp, &newdir, cnp->cn_context);
                break;

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

                cnp->cn_flags &= ~DOWHITEOUT;
                error = ufs_dirremove(dvp, cnp);
                break;
        }
        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.
 */
int
ufs_rename(ap)
        struct vnop_rename_args  /* {
                struct vnode *a_fdvp;
                struct vnode *a_fvp;
                struct componentname *a_fcnp;
                struct vnode *a_tdvp;
                struct vnode *a_tvp;
                struct componentname *a_tcnp;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *tvp = ap->a_tvp;
        register 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;
        vfs_context_t ctx = fcnp->cn_context;
        struct proc *p = vfs_context_proc(ctx);
        struct inode *ip, *xp, *dp;
        struct dirtemplate dirbuf;
        struct timeval tv;
        ino_t doingdirectory = 0, oldparent = 0, newparent = 0;
        int error = 0, ioflag;
        u_char namlen;
        struct vnode *rl_vp = NULL;


        /*
         * Check if just deleting a link name or if we've lost a race.
         * If another process completes the same rename after we've looked
         * up the source and have blocked looking up the target, then the
         * source and target inodes may be identical now although the
         * names were never linked.
         */
        if (fvp == tvp) {
                if (fvp->v_type == VDIR) {
                        /*
                         * Linked directories are impossible, so we must
                         * have lost the race.  Pretend that the rename
                         * completed before the lookup.
                         */
#ifdef UFS_RENAME_DEBUG
                        printf("ufs_rename: fvp == tvp for directories\n");
#endif
                        error = ENOENT;
                        goto abortit;
                }

                /*
                 * don't need to check in here for permissions, must already have been granted
                 * ufs_remove_internal now does the relookup
                 */
                error = ufs_remove_internal(fdvp, fvp, fcnp, 0);

                return (error);
        }
        /*
         * because the vnode_authorization code may have looked up in this directory
         * between the original lookup and the actual call to VNOP_RENAME, we need
         * to reset the directory hints... since we haven't dropped the FSNODELOCK
         * on tdvp since this whole thing started, we expect relookup to return
         * tvp (which may be NULL)
         */
        tcnp->cn_flags &= ~MODMASK;
        tcnp->cn_flags |= (WANTPARENT | NOCACHE);

        if ( (error = relookup(tdvp, &rl_vp, tcnp)) )
                panic("ufs_rename: relookup on target returned error");
        if (rl_vp != tvp) {
                /*
                 * Don't panic. The only way this state will be reached is if
                 * another rename has taken effect. In that case, it's safe
                 * to restart this rename and let things sort themselves out.
                 */
                if (rl_vp)
                        vnode_put(rl_vp);
                error = ERESTART;
                goto abortit;
        }
        if (rl_vp) {
                vnode_put(rl_vp);
                rl_vp = NULL;
        }
        dp = VTOI(fdvp);
        ip = VTOI(fvp);

        if ((ip->i_mode & IFMT) == IFDIR) {
                if (ip->i_flag & IN_RENAME) {
                        error = EINVAL;
                        goto abortit;
                }
                ip->i_flag |= IN_RENAME;
                oldparent = dp->i_number;
                doingdirectory++;
        }
        VN_KNOTE(fdvp, NOTE_WRITE);             /* XXX right place? */

        /*
         * When the target exists, both the directory
         * and target vnodes are returned locked.
         */
        dp = VTOI(tdvp);
        xp = NULL;
        if (tvp)
                xp = VTOI(tvp);

        /*
         * 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_nlink++;
        ip->i_flag |= IN_CHANGE;
        microtime(&tv);
        if ( (error = ffs_update(fvp, &tv, &tv, 1)) ) {
                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().
         */

        if (oldparent != dp->i_number)
                newparent = dp->i_number;

        if (doingdirectory && newparent) {
                if (error)      /* write access check above */
                        goto bad;

                if ( (error = ufs_checkpath(ip, dp, vfs_context_ucred(tcnp->cn_context))) )
                        goto bad;

                if ( (error = relookup(tdvp, &tvp, tcnp)) )
                        goto bad;
                rl_vp = tvp;

                dp = VTOI(tdvp);
                if (tvp)
                        xp = VTOI(tvp);
                else
                        xp = NULL;
        }
        /*
         * 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("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_nlink++;
                        dp->i_flag |= IN_CHANGE;
                        if ( (error = ffs_update(tdvp, &tv, &tv, 1)) )
                                goto bad;
                }
                if ( (error = ufs_direnter(ip, tdvp, tcnp)) ) {
                        if (doingdirectory && newparent) {
                                dp->i_nlink--;
                                dp->i_flag |= IN_CHANGE;
                                (void)ffs_update(tdvp, &tv, &tv, 1);
                        }
                        goto bad;
                }
                VN_KNOTE(tdvp, NOTE_WRITE);
        } else {
                if (xp->i_dev != dp->i_dev || xp->i_dev != ip->i_dev)
                        panic("rename: EXDEV");
                /*
                 * Short circuit rename(foo, foo).
                 */
                if (xp->i_number == ip->i_number)
                        panic("rename: same file");
                /*
                 * 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).
                 */
                if ((xp->i_mode&IFMT) == IFDIR) {
                        if (!ufs_dirempty(xp, dp->i_number, vfs_context_ucred(tcnp->cn_context)) || 
                            xp->i_nlink > 2) {
                                error = ENOTEMPTY;
                                goto bad;
                        }
                        if (!doingdirectory) {
                                error = ENOTDIR;
                                goto bad;
                        }
                        cache_purge(tdvp);
                } else if (doingdirectory) {
                        error = EISDIR;
                        goto bad;
                }
                if ( (error = ufs_dirrewrite(dp, ip, tcnp)) )
                        goto bad;
                /*
                 * If the target directory is in the same
                 * directory as the source directory,
                 * decrement the link count on the parent
                 * of the target directory.
                 */
                 if (doingdirectory && !newparent) {
                        dp->i_nlink--;
                        dp->i_flag |= IN_CHANGE;
                }
                VN_KNOTE(tdvp, NOTE_WRITE);
                /*
                 * Adjust the link count of the target to
                 * reflect the dirrewrite above.  If this is
                 * a directory it is empty and there are
                 * no links to it, so we can squash the inode and
                 * any space associated with it.  We disallowed
                 * renaming over top of a directory with links to
                 * it above, as the remaining link would point to
                 * a directory without "." or ".." entries.
                 */
                xp->i_nlink--;
                if (doingdirectory) {
                        if (--xp->i_nlink != 0)
                                panic("rename: linked directory");
                        ioflag = ((tvp)->v_mount->mnt_flag & MNT_ASYNC) ?
                            0 : IO_SYNC;
                        error = ffs_truncate_internal(tvp, (off_t)0, ioflag, vfs_context_ucred(tcnp->cn_context));
                }
                xp->i_flag |= IN_CHANGE;
                VN_KNOTE(tvp, NOTE_DELETE);
                xp = NULL;
        }
        if (rl_vp)
                vnode_put(rl_vp);
        rl_vp = NULL;
        
        /*
         * 3) Unlink the source.
         */
        fcnp->cn_flags &= ~MODMASK;
        fcnp->cn_flags |= (WANTPARENT | NOCACHE);

        (void) relookup(fdvp, &fvp, fcnp);

        if (fvp != NULL) {
                xp = VTOI(fvp);
                dp = VTOI(fdvp);
                rl_vp = fvp;
        } else {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("rename: lost dir entry");

                return (0);
        }
        /*
         * 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; its link
         * count of three would cause a rmdir to fail with ENOTEMPTY.
         * The IN_RENAME flag ensures that it cannot be moved by another
         * rename.
         */
        if (xp != ip) {
                if (doingdirectory)
                        panic("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) {
                        dp->i_nlink--;
                        dp->i_flag |= IN_CHANGE;
                        error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
                                sizeof (struct dirtemplate), (off_t)0,
                                UIO_SYSSPACE32, IO_NODELOCKED, 
                                vfs_context_ucred(tcnp->cn_context), (int *)0, (struct proc *)0);
                        if (error == 0) {
#                               if (BYTE_ORDER == LITTLE_ENDIAN)
                                        if (fvp->v_mount->mnt_maxsymlinklen <= 0)
                                                namlen = dirbuf.dotdot_type;
                                        else
                                                namlen = dirbuf.dotdot_namlen;
#                               else
                                        namlen = dirbuf.dotdot_namlen;
#                               endif
                                if (namlen != 2 ||
                                    dirbuf.dotdot_name[0] != '.' ||
                                    dirbuf.dotdot_name[1] != '.') {
                                        ufs_dirbad(xp, (doff_t)12,
                                            "rename: mangled dir");
                                } else {
                                        dirbuf.dotdot_ino = newparent;
                                        (void) vn_rdwr(UIO_WRITE, fvp,
                                            (caddr_t)&dirbuf,
                                            sizeof (struct dirtemplate),
                                            (off_t)0, UIO_SYSSPACE32,
                                            IO_NODELOCKED|IO_SYNC,
                                            vfs_context_ucred(tcnp->cn_context), (int *)0,
                                            (struct proc *)0);
                                        cache_purge(fdvp);
                                }
                        }
                }
                error = ufs_dirremove(fdvp, fcnp);
                if (!error) {
                        xp->i_nlink--;
                        xp->i_flag |= IN_CHANGE;
                }
                xp->i_flag &= ~IN_RENAME;
        }
        VN_KNOTE(fvp, NOTE_RENAME);

        if (rl_vp)
                vnode_put(rl_vp);

        return (error);

bad:
        if (rl_vp)
                vnode_put(rl_vp);

        if (doingdirectory)
                ip->i_flag &= ~IN_RENAME;

        ip->i_nlink--;
        ip->i_flag |= IN_CHANGE;
        ip->i_flag &= ~IN_RENAME;

abortit:
        return (error);
}

/*
 * 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, ".."
};

/*
 * Mkdir system call
 */
int
ufs_mkdir(ap)
        struct vnop_mkdir_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vnode_attr *a_vap;
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *dvp = ap->a_dvp;
        register struct vnode_attr *vap = ap->a_vap;
        register struct componentname *cnp = ap->a_cnp;
        register struct inode *ip, *dp;
        struct vnode *tvp;
        struct dirtemplate dirtemplate, *dtp;
        struct timeval tv;
        int error, dmode;

        /* use relookup to force correct directory hints */
        cnp->cn_flags &= ~MODMASK;
        cnp->cn_flags |= (WANTPARENT | NOCACHE);
        cnp->cn_nameiop = CREATE;

        (void) relookup(dvp, &tvp, cnp);

        /* get rid of reference relookup returned */
        if (tvp)
                vnode_put(tvp);

        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.
         */
        if ( (error = ffs_valloc(dvp, (mode_t)dmode, vfs_context_ucred(cnp->cn_context), &tvp)) )
                goto out;
        ip = VTOI(tvp);
        ip->i_uid = ap->a_vap->va_uid;
        ip->i_gid = ap->a_vap->va_gid;
        VATTR_SET_SUPPORTED(ap->a_vap, va_mode);
        VATTR_SET_SUPPORTED(ap->a_vap, va_uid);
        VATTR_SET_SUPPORTED(ap->a_vap, va_gid);
#if QUOTA
        if ((error = getinoquota(ip)) ||
            (error = chkiq(ip, 1, vfs_context_ucred(cnp->cn_context), 0))) {
                ffs_vfree(tvp, ip->i_number, dmode);
                vnode_put(tvp);
                return (error);
        }
#endif
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = dmode;
        ip->i_nlink = 2;
        if (cnp->cn_flags & ISWHITEOUT)
                ip->i_flags |= UF_OPAQUE;
        microtime(&tv);
        error = ffs_update(tvp, &tv, &tv, 1);

        /*
         * Bump link count in parent directory
         * to reflect work done below.  Should
         * be done before reference is created
         * so reparation is possible if we crash.
         */
        dp->i_nlink++;
        dp->i_flag |= IN_CHANGE;
        if ( (error = ffs_update(dvp, &tv, &tv, 1)) )
                goto bad;

        /* 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;
        error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
            sizeof (dirtemplate), (off_t)0, UIO_SYSSPACE32,
            IO_NODELOCKED|IO_SYNC, vfs_context_ucred(cnp->cn_context), (int *)0, (struct proc *)0);
        if (error) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
                goto bad;
        }
        if (DIRBLKSIZ > VFSTOUFS(dvp->v_mount)->um_mountp->mnt_vfsstat.f_bsize)
                panic("ufs_mkdir: blksize"); /* XXX should grow with balloc() */
        else {
                ip->i_size = DIRBLKSIZ;
                ip->i_flag |= IN_CHANGE;
        }

        /* Directory set up, now install it's entry in the parent directory. */
        if ( (error = ufs_direnter(ip, dvp, cnp)) ) {
                dp->i_nlink--;
                dp->i_flag |= IN_CHANGE;
        }
bad:
        /*
         * No need to do an explicit vnop_truncate here, vnode_put will do it
         * for us because we set the link count to 0.
         */
        if (error) {
                ip->i_nlink = 0;
                ip->i_flag |= IN_CHANGE;
                /*
                 * since we're not returning tvp due to the error,
                 * we're responsible for releasing it here
                 */
                vnode_put(tvp);
        } else {
                VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
                *ap->a_vpp = tvp;
        };
out:
        return (error);
}

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


        ip = VTOI(vp);
        dp = VTOI(dvp);
        /*
         * No rmdir "." please.
         */
        if (dp == ip)
                return (EINVAL);


        cnp->cn_flags &= ~MODMASK;
        cnp->cn_flags |= (WANTPARENT | NOCACHE);

        (void) relookup(dvp, &tvp, cnp);

        if (tvp == NULL)
                return (ENOENT);
        if (tvp != vp)
                panic("ufs_rmdir: relookup returned a different vp");
        /*
         * get rid of reference relookup returned
         */
        vnode_put(tvp);


        /*
         * Verify the directory is empty (and valid).
         * (Rmdir ".." won't be valid since
         *  ".." will contain a reference to
         *  the current directory and thus be
         *  non-empty.)
         */
        error = 0;
        if (ip->i_nlink != 2 ||
            !ufs_dirempty(ip, dp->i_number, vfs_context_ucred(cnp->cn_context))) {
                error = ENOTEMPTY;
                goto out;
        }
        /*
         * Delete reference to directory before purging
         * inode.  If we crash in between, the directory
         * will be reattached to lost+found,
         */
        if ( (error = ufs_dirremove(dvp, cnp)) )
                goto out;
        VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
        dp->i_nlink--;
        dp->i_flag |= IN_CHANGE;
        cache_purge(dvp);
        /*
         * Truncate inode.  The only stuff left
         * in the directory is "." and "..".  The
         * "." reference is inconsequential since
         * we're quashing it.  The ".." reference
         * has already been adjusted above.  We've
         * removed the "." reference and the reference
         * in the parent directory, but there may be
         * other hard links so decrement by 2 and
         * worry about them later.
         */
        ip->i_nlink -= 2;
        ioflag = ((vp)->v_mount->mnt_flag & MNT_ASYNC) ? 0 : IO_SYNC;
        error = ffs_truncate_internal(vp, (off_t)0, ioflag, vfs_context_ucred(cnp->cn_context));
        cache_purge(ITOV(ip));
out:
        VN_KNOTE(vp, NOTE_DELETE);
        return (error);
}

/*
 * symlink -- make a symbolic link
 */
int
ufs_symlink(ap)
        struct vnop_symlink_args /* {
                struct vnode *a_dvp;
                struct vnode **a_vpp;
                struct componentname *a_cnp;
                struct vnode_attr *a_vap;
                char *a_target;
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp, **vpp = ap->a_vpp;
        register struct inode *ip;
        int len, error;

        if ( (error = ufs_makeinode(ap->a_vap, ap->a_dvp, vpp, ap->a_cnp)) )
                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
                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                    UIO_SYSSPACE32, IO_NODELOCKED, vfs_context_ucred(ap->a_cnp->cn_context), (int *)0,
                    (struct proc *)0);
        return (error);
}

/*
 * Vnode op for reading directories.
 * 
 * The routine below assumes that the on-disk format of a directory
 * is the same as that defined by <sys/dirent.h>. If the on-disk
 * format changes, then it will be necessary to do a conversion
 * from the on-disk format that read returns to the format defined
 * by <sys/dirent.h>.
 */
int
ufs_readdir(ap)
        struct vnop_readdir_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int a_flags;
                int *a_eofflag;
                int *a_numdirent;
                vfs_context_t a_context;
        } */ *ap;
{
        struct uio *uio = ap->a_uio;
        int error;
        size_t count, lost;

        if (ap->a_flags & VNODE_READDIR_EXTENDED) {
                return ufs_readdirext(ap->a_vp, uio, ap->a_eofflag,
                                      ap->a_numdirent, ap->a_context);
        }

        // LP64todo - fix this
        count = uio_resid(uio);
        /* Make sure we don't return partial entries. */
        count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
        if (count <= 0)
                return (EINVAL);
        // LP64todo - fix this
        lost = uio_resid(uio) - count;
        uio_setresid(uio, count);
        uio_iov_len_set(uio, count);
#       if (BYTE_ORDER == LITTLE_ENDIAN)
                if (ap->a_vp->v_mount->mnt_maxsymlinklen > 0) {
                        error = ffs_read_internal(ap->a_vp, uio, 0);
                } else {
                        struct dirent *dp, *edp;
                        struct uio auio;
                        struct iovec_32 aiov;
                        caddr_t dirbuf;
                        int readcnt;
                        u_char tmp;

                        auio = *uio;
                        auio.uio_iovs.iov32p = &aiov;
                        auio.uio_iovcnt = 1;
#if 1   /* LP64todo - can't use new segment flags until the drivers are ready */
                        auio.uio_segflg = UIO_SYSSPACE;
#else
                        auio.uio_segflg = UIO_SYSSPACE32;
#endif 
                        aiov.iov_len = count;
                        MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
                        aiov.iov_base = (uintptr_t)dirbuf;
                        error = ffs_read_internal(ap->a_vp, &auio, 0);
                        if (error == 0) {
                                // LP64todo - fix this
                                readcnt = count - uio_resid(&auio);
                                edp = (struct dirent *)&dirbuf[readcnt];
                                for (dp = (struct dirent *)dirbuf; dp < edp; ) {
                                        tmp = dp->d_namlen;
                                        dp->d_namlen = dp->d_type;
                                        dp->d_type = tmp;
                                        if (dp->d_reclen > 0) {
                                                dp = (struct dirent *)
                                                    ((char *)dp + dp->d_reclen);
                                        } else {
                                                error = EIO;
                                                break;
                                        }
                                }
                                if (dp >= edp)
                                        error = uiomove(dirbuf, readcnt, uio);
                        }
                        FREE(dirbuf, M_TEMP);
                }
#       else
                error = ffs_read_internal(ap->a_vp, uio, 0);
#       endif

        uio_setresid(uio, (uio_resid(uio) + lost));
        if (ap->a_eofflag)
                *ap->a_eofflag = (off_t)VTOI(ap->a_vp)->i_size <= uio->uio_offset;
        return (error);
}


/*
 *  ufs_readdirext reads directory entries into the buffer pointed
 *  to by uio, in a filesystem independent format.  Up to uio_resid
 *  bytes of data can be transferred.  The data in the buffer is a
 *  series of packed direntry structures where each one contains the
 *  following entries:
 *
 *      d_reclen:   length of record
 *      d_ino:      file number of entry
 *      d_seekoff:  seek offset (used by NFS server, aka cookie)
 *      d_type:     file type
 *      d_namlen:   length of string in d_name
 *      d_name:     null terminated file name
 *
 *  The current position (uio_offset) refers to the next block of
 *  entries.  The offset will only be set to a value previously
 *  returned by ufs_readdirext or zero.  This offset does not have
 *  to match the number of bytes returned (in uio_resid).
 */
#define EXT_DIRENT_LEN(namlen) \
        ((sizeof(struct direntry) + (namlen) - (MAXPATHLEN-1) + 3) & ~3)

static int
ufs_readdirext(vnode_t vp, uio_t uio, int *eofflag, int *numdirent,
               __unused vfs_context_t context)
{
        int error;
        size_t count, lost;
        off_t off = uio->uio_offset;
        struct dirent *dp, *edp;
        struct uio auio;
        struct iovec_32 aiov;
        caddr_t dirbuf;
        struct direntry *xdp;
        int nentries = 0;

        // LP64todo - fix this
        count = uio_resid(uio);
        /* Make sure we don't return partial entries. */
        count -= (uio->uio_offset + count) & (DIRBLKSIZ -1);
        if (count <= 0)
                return (EINVAL);
        // LP64todo - fix this
        lost = uio_resid(uio) - count;
        uio_setresid(uio, count);
        uio_iov_len_set(uio, count);

        auio = *uio;
        auio.uio_iovs.iov32p = &aiov;
        auio.uio_iovcnt = 1;
        /* LP64todo - can't use new segment flags until the drivers are ready */
        auio.uio_segflg = UIO_SYSSPACE;
        aiov.iov_len = count;
        MALLOC(dirbuf, caddr_t, count, M_TEMP, M_WAITOK);
        aiov.iov_base = (uintptr_t)dirbuf;

        MALLOC(xdp, struct direntry *, sizeof(struct direntry), M_TEMP, M_WAITOK);

        error = ffs_read_internal(vp, &auio, 0);
        if (error)
                goto out;

        // LP64todo - fix this
        edp = (struct dirent *)&dirbuf[count - uio_resid(&auio)];
        for (dp = (struct dirent *)dirbuf; dp < edp; ) {

#if (BYTE_ORDER == LITTLE_ENDIAN)
                u_char tmp;

                tmp = dp->d_namlen;
                dp->d_namlen = dp->d_type;
                dp->d_type = tmp;
#endif
                xdp->d_reclen = EXT_DIRENT_LEN(dp->d_namlen);
                if (xdp->d_reclen > uio_resid(uio)) {
                        break;  /* user buffer is full */
                }
                xdp->d_ino = dp->d_ino;
                xdp->d_namlen = dp->d_namlen;
                xdp->d_type = dp->d_type;
                bcopy(dp->d_name, xdp->d_name, dp->d_namlen + 1);
                off += dp->d_reclen;
                xdp->d_seekoff = off;
                error = uiomove((caddr_t)xdp, xdp->d_reclen, uio);
                if (error) {
                        off -= dp->d_reclen;
                        break;  /* unexpected this error is */
                }
                nentries++;

                if (dp->d_reclen > 0) {
                        dp = (struct dirent *)
                            ((char *)dp + dp->d_reclen);
                } else {
                        error = EIO;
                        break;
                }
        }
out:
        FREE(dirbuf, M_TEMP);
        FREE(xdp, M_TEMP);

        /* Use the on-disk dirent offset */
        uio_setoffset(uio, off);
        *numdirent = nentries;
        uio_setresid(uio, (uio_resid(uio) + lost));
        if (eofflag)
                *eofflag = (off_t)VTOI(vp)->i_size <= uio->uio_offset;
        return (error);
}


/*
 * Return target name of a symbolic link
 */
int
ufs_readlink(ap)
        struct vnop_readlink_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                vfs_context_t a_context;
        } */ *ap;
{
        register struct vnode *vp = ap->a_vp;
        register struct inode *ip = VTOI(vp);
        int isize;

        isize = ip->i_size;
        if (isize < vp->v_mount->mnt_maxsymlinklen) {
                uiomove((char *)ip->i_shortlink, isize, ap->a_uio);
                return (0);
        }
        return (ffs_read_internal(vp, ap->a_uio, 0));
}

/*
 * prepare and issue the I/O
 */
errno_t
ufs_strategy(ap)
        struct vnop_strategy_args /* {
                struct buf *a_bp;
        } */ *ap;
{
        buf_t   bp = ap->a_bp;
        vnode_t vp = buf_vnode(bp);
        struct inode *ip = VTOI(vp);

        return (buf_strategy(ip->i_devvp, ap));
}

/*
 * Read wrapper for special devices.
 */
int
ufsspec_read(ap)
        struct vnop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{

        /*
         * Set access flag.
         */
        VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_read), ap));
}

/*
 * Write wrapper for special devices.
 */
int
ufsspec_write(
        struct vnop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                kauth_cred_t a_cred;
        } */ *ap)
{

        /*
         * Set update and change flags.
         */
        VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_write), ap));
}

/*
 * Close wrapper for special devices.
 *
 * Update the times on the inode then do device close.
 */
int
ufsspec_close(ap)
        struct vnop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                vfs_context_t a_context;
        } */ *ap;
{
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct timeval tv;

        if (ap->a_vp->v_usecount > 1) {
                microtime(&tv);
                ITIMES(ip, &tv, &tv);
        }
        return (VOCALL (spec_vnodeop_p, VOFFSET(vnop_close), ap));
}

#if FIFO
/*
 * Read wrapper for fifo's
 */
int
ufsfifo_read(ap)
        struct vnop_read_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                vfs_context_t a_context;
        } */ *ap;
{
        extern int (**fifo_vnodeop_p)(void *);

        /*
         * Set access flag.
         */
        VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_read), ap));
}

/*
 * Write wrapper for fifo's.
 */
int
ufsfifo_write(
        struct vnop_write_args /* {
                struct vnode *a_vp;
                struct uio *a_uio;
                int  a_ioflag;
                kauth_cred_t a_cred;
        } */ *ap)
{
        extern int (**fifo_vnodeop_p)(void *);

        /*
         * Set update and change flags.
         */
        VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_write), ap));
}

/*
 * Close wrapper for fifo's.
 *
 * Update the times on the inode then do device close.
 */
int
ufsfifo_close(ap)
        struct vnop_close_args /* {
                struct vnode *a_vp;
                int  a_fflag;
                vfs_context_t a_context;
        } */ *ap;
{
        extern int (**fifo_vnodeop_p)(void *);
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        struct timeval tv;

        if (ap->a_vp->v_usecount > 1) {
                microtime(&tv);
                ITIMES(ip, &tv, &tv);
        }
        return (VOCALL (fifo_vnodeop_p, VOFFSET(vnop_close), ap));
}

/*
 * kqfilt_add wrapper for fifos.
 *
 * Fall through to ufs kqfilt_add routines if needed 
 */
int
ufsfifo_kqfilt_add(ap)
        struct vnop_kqfilt_add_args *ap;
{
        extern int (**fifo_vnodeop_p)(void *);
        int error;

        error = VOCALL(fifo_vnodeop_p, VOFFSET(vnop_kqfilt_add), ap);
        if (error)
                error = ufs_kqfilt_add(ap);
        return (error);
}

#if 0
/*
 * kqfilt_remove wrapper for fifos.
 *
 * Fall through to ufs kqfilt_remove routines if needed 
 */
int
ufsfifo_kqfilt_remove(ap)
        struct vnop_kqfilt_remove_args *ap;
{
        extern int (**fifo_vnodeop_p)(void *);
        int error;

        error = VOCALL(fifo_vnodeop_p, VOFFSET(vnop_kqfilt_remove), ap);
        if (error)
                error = ufs_kqfilt_remove(ap);
        return (error);
}
#endif

#endif /* FIFO */


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

/*
 #
 #% kqfilt_add  vp      L L L
 #
 vnop_kqfilt_add
        IN struct vnode *vp;
        IN struct knote *kn;
        IN vfs_context_t context;
 */
int
ufs_kqfilt_add(ap)
        struct vnop_kqfilt_add_args /* {
                struct vnode *a_vp;
                struct knote *a_kn;
                vfs_context_t a_context;
        } */ *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 (1);
        }

        kn->kn_hook = (caddr_t)vp;
        kn->kn_hookid = vnode_vid(vp);

        KNOTE_ATTACH(&VTOI(vp)->i_knotes, kn);

        return (0);
}

static void
filt_ufsdetach(struct knote *kn)
{
        struct vnode *vp;
        int result;
        struct proc *p = current_proc();
        
        vp = (struct vnode *)kn->kn_hook;

        if (vnode_getwithvid(vp, kn->kn_hookid))
                return;

        result = KNOTE_DETACH(&VTOI(vp)->i_knotes, kn);
        vnode_put(vp);
}

static int
filt_ufsread(struct knote *kn, long hint)
{
        struct vnode *vp = (struct vnode *)kn->kn_hook;
        struct inode *ip;
        int dropvp = 0;
        int result;

        if (hint == 0)  {
                if ((vnode_getwithvid(vp, kn->kn_hookid) != 0)) {
                        hint = NOTE_REVOKE;
                } else 
                        dropvp = 1;
        }
        if (hint == NOTE_REVOKE) {
                /*
                 * filesystem is gone, so set the EOF flag and schedule 
                 * the knote for deletion.
                 */
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);
                return (1);
        }

        /* poll(2) semantics dictate always returning true */
        if (kn->kn_flags & EV_POLL) {
                kn->kn_data = 1;
                result = 1;
        } else {
                ip = VTOI(vp);
                kn->kn_data = ip->i_size - kn->kn_fp->f_fglob->fg_offset;
                result = (kn->kn_data != 0);
        }

        if  (dropvp)
                vnode_put(vp);

        return (result);
}

static int
filt_ufswrite(struct knote *kn, long hint)
{

        int dropvp = 0;
        
        if (hint == 0)  {
                if ((vnode_getwithvid(kn->kn_hook, kn->kn_hookid) != 0)) {
                        hint = NOTE_REVOKE;
                } else 
                        vnode_put(kn->kn_hook);
        }
        if (hint == NOTE_REVOKE) {
                /*
                 * filesystem is gone, so set the EOF flag and schedule 
                 * the knote for deletion.
                 */
                kn->kn_data = 0;
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);
                return (1);
        }
        kn->kn_data = 0;
        return (1);
}

static int
filt_ufsvnode(struct knote *kn, long hint)
{

        if (hint == 0)  {
                if ((vnode_getwithvid(kn->kn_hook, kn->kn_hookid) != 0)) {
                        hint = NOTE_REVOKE;
                } else
                        vnode_put(kn->kn_hook);
        }
        if (kn->kn_sfflags & hint)
                kn->kn_fflags |= hint;
        if ((hint == NOTE_REVOKE)) {
                kn->kn_flags |= (EV_EOF | EV_ONESHOT);
                return (1);
        }
        
        return (kn->kn_fflags != 0);
}

/*
 * Return POSIX pathconf information applicable to ufs filesystems.
 */
int
ufs_pathconf(ap)
        struct vnop_pathconf_args /* {
                struct vnode *a_vp;
                int a_name;
                int *a_retval;
                vfs_context_t a_context;
        } */ *ap;
{

        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = LINK_MAX;
                return (0);
        case _PC_NAME_MAX:
                *ap->a_retval = NAME_MAX;
                return (0);
        case _PC_PATH_MAX:
                *ap->a_retval = PATH_MAX;
                return (0);
        case _PC_PIPE_BUF:
                *ap->a_retval = PIPE_BUF;
                return (0);
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                return (0);
        case _PC_NO_TRUNC:
                *ap->a_retval = 1;
                return (0);
        default:
                return (EINVAL);
        }
        /* NOTREACHED */
}

/*
 * Allocate a new inode.
 */
int
ufs_makeinode(vap, dvp, vpp, cnp)
        struct vnode_attr *vap;
        struct vnode *dvp;
        struct vnode **vpp;
        struct componentname *cnp;
{
        register struct inode *ip, *pdir;
        struct timeval tv;
        struct vnode *tvp;
        int error;
        int is_member;
        int mode;
        
        mode = MAKEIMODE(vap->va_type, vap->va_mode);
        pdir = VTOI(dvp);
        *vpp = NULL;
        if ((mode & IFMT) == 0)
                mode |= IFREG;

        if ( (error = ffs_valloc(dvp, (mode_t)mode, vfs_context_ucred(cnp->cn_context), &tvp)) )
                return (error);

        ip = VTOI(tvp);
        ip->i_gid = vap->va_gid;
        ip->i_uid = vap->va_uid;
        VATTR_SET_SUPPORTED(vap, va_mode);
        VATTR_SET_SUPPORTED(vap, va_uid);
        VATTR_SET_SUPPORTED(vap, va_gid);
#if QUOTA
        if ((error = getinoquota(ip)) ||
            (error = chkiq(ip, 1, vfs_context_ucred(cnp->cn_context), 0))) {
                ffs_vfree(tvp, ip->i_number, mode);
                vnode_put(tvp);
                return (error);
        }
#endif
        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        ip->i_mode = mode;
        ip->i_nlink = 1;

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

        /*
         * Make sure inode goes to disk before directory entry.
         */
        microtime(&tv);
        if ( (error = ffs_update(tvp, &tv, &tv, 1)) )
                goto bad;
        if ( (error = ufs_direnter(ip, dvp, cnp)) )
                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_nlink = 0;
        ip->i_flag |= IN_CHANGE;
        vnode_put(tvp);

        return (error);
}