/*      $OpenBSD: ufs_vnops.c,v 1.164 2024/10/18 05:52:33 miod Exp $    */
/*      $NetBSD: ufs_vnops.c,v 1.18 1996/05/11 18:28:04 mycroft Exp $   */

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *      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 8.14 (Berkeley) 10/26/94
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/pool.h>
#include <sys/dirent.h>
#include <sys/lockf.h>
#include <sys/event.h>
#include <sys/specdev.h>
#include <sys/unistd.h>

#include <miscfs/fifofs/fifo.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>
#ifdef UFS_DIRHASH
#include <ufs/ufs/dirhash.h>
#endif
#include <ufs/ext2fs/ext2fs_extern.h>

#include <uvm/uvm_extern.h>

int ufs_chmod(struct vnode *, int, struct ucred *);
int ufs_chown(struct vnode *, uid_t, gid_t, struct ucred *);
int filt_ufsread(struct knote *, long);
int filt_ufswrite(struct knote *, long);
int filt_ufsvnode(struct knote *, long);
void filt_ufsdetach(struct knote *);

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

/*
 * Update the times in the inode
 */
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_mount->mnt_flag & MNT_RDONLY)
                goto out;

#ifdef EXT2FS
        if (IS_EXT2_VNODE(ip->i_vnode)) {
                EXT2FS_ITIMES(ip);
                goto out;
        }
#endif

        if ((vp->v_type == VBLK || vp->v_type == VCHR))
                ip->i_flag |= IN_LAZYMOD;
        else
                ip->i_flag |= IN_MODIFIED;

        getnanotime(&ts);
        if (ip->i_flag & IN_ACCESS) {
                DIP_ASSIGN(ip, atime, ts.tv_sec);
                DIP_ASSIGN(ip, atimensec, ts.tv_nsec);
        }
        if (ip->i_flag & IN_UPDATE) {
                DIP_ASSIGN(ip, mtime, ts.tv_sec);
                DIP_ASSIGN(ip, mtimensec, ts.tv_nsec);
        }
        if (ip->i_flag & IN_CHANGE) {
                DIP_ASSIGN(ip, ctime, ts.tv_sec);
                DIP_ASSIGN(ip, ctimensec, ts.tv_nsec);
                ip->i_modrev++;
        }

 out:
        ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
}


/*
 * Create a regular file
 */
int
ufs_create(void *v)
{
        struct vop_create_args *ap = v;
        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 == 0)
                VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        return (error);
}

/*
 * Mknod vnode call
 */
int
ufs_mknod(void *v)
{
        struct vop_mknod_args *ap = v;
        struct vattr *vap = ap->a_vap;
        struct vnode **vpp = ap->a_vpp;
        struct inode *ip;
        int error;

        if ((error =
            ufs_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
            ap->a_dvp, vpp, ap->a_cnp)) != 0)
                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.
                 */
                DIP_ASSIGN(ip, rdev, vap->va_rdev);
        }
        /*
         * Remove inode so that it will be reloaded by VFS_VGET and
         * checked to see if it is an alias of an existing entry in
         * the inode cache.
         */
        vput(*vpp);
        (*vpp)->v_type = VNON;
        vgone(*vpp);
        *vpp = NULL;
        return (0);
}

/*
 * Open called.
 *
 * Nothing to do.
 */
int
ufs_open(void *v)
{
        struct vop_open_args *ap = v;
        struct inode *ip = VTOI(ap->a_vp);

        /*
         * Files marked append-only must be opened for appending.
         */
        if ((DIP(ip, flags) & APPEND) &&
            (ap->a_mode & (FWRITE | O_APPEND)) == FWRITE)
                return (EPERM);

        if (ap->a_mode & O_TRUNC)
                ip->i_flag |= IN_CHANGE | IN_UPDATE;

        return (0);
}

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

        if (vp->v_usecount > 1)
                ufs_itimes(vp);
        return (0);
}

int
ufs_access(void *v)
{
        struct vop_access_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        mode_t mode = ap->a_mode;

        /*
         * Disallow write attempts on read-only file systems;
         * unless the file is a socket, fifo, or a block or
         * character device resident on the file system.
         */
        if (mode & VWRITE) {
                switch (vp->v_type) {
                        int error;
                case VDIR:
                case VLNK:
                case VREG:
                        if (vp->v_mount->mnt_flag & MNT_RDONLY)
                                return (EROFS);

                        if ((error = getinoquota(ip)) != 0)
                                return (error);
                        break;
                case VBAD:
                case VBLK:
                case VCHR:
                case VSOCK:
                case VFIFO:
                case VNON:
                        break;

                }
        }

        /* If immutable bit set, nobody gets to write it. */
        if ((mode & VWRITE) && (DIP(ip, flags) & IMMUTABLE))
                return (EPERM);

        if (vnoperm(vp)) {
                /* For VEXEC, at least one of the execute bits must be set. */
                if ((mode & VEXEC) && vp->v_type != VDIR &&
                    (DIP(ip, mode) & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)
                        return EACCES;
                return 0;
        }

        return (vaccess(vp->v_type, DIP(ip, mode), DIP(ip, uid), DIP(ip, gid),
            mode, ap->a_cred));
}

int
ufs_getattr(void *v)
{
        struct vop_getattr_args *ap = v;
        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 = ip->i_dev;
        vap->va_fileid = ip->i_number;
        vap->va_mode = DIP(ip, mode) & ~IFMT;
        vap->va_nlink = ip->i_effnlink;
        vap->va_uid = DIP(ip, uid);
        vap->va_gid = DIP(ip, gid);
        vap->va_rdev = (dev_t) DIP(ip, rdev);
        vap->va_size = DIP(ip, size);
        vap->va_atime.tv_sec = DIP(ip, atime);
        vap->va_atime.tv_nsec = DIP(ip, atimensec);
        vap->va_mtime.tv_sec = DIP(ip, mtime);
        vap->va_mtime.tv_nsec = DIP(ip, mtimensec);
        vap->va_ctime.tv_sec = DIP(ip, ctime);
        vap->va_ctime.tv_nsec = DIP(ip, ctimensec);
        vap->va_flags = DIP(ip, flags);
        vap->va_gen = DIP(ip, gen);
        /* this doesn't belong here */
        if (vp->v_type == VBLK)
                vap->va_blocksize = BLKDEV_IOSIZE;
        else if (vp->v_type == VCHR)
                vap->va_blocksize = MAXBSIZE;
        else
                vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
        vap->va_bytes = dbtob((u_quad_t) DIP(ip, blocks));
        vap->va_type = vp->v_type;
        vap->va_filerev = ip->i_modrev;
        return (0);
}

/*
 * Set attribute vnode op. called from several syscalls
 */
int
ufs_setattr(void *v)
{
        struct vop_setattr_args *ap = v;
        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;
        long hint = NOTE_ATTRIB;
        u_quad_t oldsize;

        /*
         * 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_rdev != 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 != DIP(ip, uid) &&
                    !vnoperm(vp) &&
                    (error = suser_ucred(cred)))
                        return (error);
                if (cred->cr_uid == 0 || vnoperm(vp)) {
                        if ((DIP(ip, flags) & (SF_IMMUTABLE | SF_APPEND)) &&
                            securelevel > 0)
                                return (EPERM);
                        DIP_ASSIGN(ip, flags, vap->va_flags);
                } else {
                        if (DIP(ip, flags) & (SF_IMMUTABLE | SF_APPEND) ||
                            (vap->va_flags & UF_SETTABLE) != vap->va_flags)
                                return (EPERM);
                        DIP_AND(ip, flags, SF_SETTABLE);
                        DIP_OR(ip, flags, vap->va_flags & UF_SETTABLE);
                }
                ip->i_flag |= IN_CHANGE;
                if (vap->va_flags & (IMMUTABLE | APPEND))
                        return (0);
        }
        if (DIP(ip, flags) & (IMMUTABLE | APPEND))
                return (EPERM);
        /*
         * Go through the fields and update if 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);
                error = ufs_chown(vp, vap->va_uid, vap->va_gid, cred);
                if (error)
                        return (error);
        }
        if (vap->va_size != VNOVAL) {
                oldsize = DIP(ip, size);
                /*
                 * Disallow write attempts on read-only file systems;
                 * unless the file is a socket, fifo, or a block or
                 * character device resident on the file system.
                 */
                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 = UFS_TRUNCATE(ip, vap->va_size, 0, cred)) != 0)
                        return (error);
                if (vap->va_size < oldsize)
                        hint |= NOTE_TRUNCATE;
        }
        if ((vap->va_vaflags & VA_UTIMES_CHANGE) ||
            vap->va_atime.tv_nsec != VNOVAL ||
            vap->va_mtime.tv_nsec != VNOVAL) {
                if (vp->v_mount->mnt_flag & MNT_RDONLY)
                        return (EROFS);
                if (cred->cr_uid != DIP(ip, uid) &&
                    !vnoperm(vp) &&
                    (error = suser_ucred(cred)) &&
                    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 || 
                    (error = VOP_ACCESS(vp, VWRITE, cred, ap->a_p))))
                        return (error);
                if (vap->va_mtime.tv_nsec != VNOVAL)
                        ip->i_flag |= IN_CHANGE | IN_UPDATE;
                else if (vap->va_vaflags & VA_UTIMES_CHANGE)
                        ip->i_flag |= IN_CHANGE;
                if (vap->va_atime.tv_nsec != VNOVAL) {
                        if (!(vp->v_mount->mnt_flag & MNT_NOATIME) ||
                            (ip->i_flag & (IN_CHANGE | IN_UPDATE)))
                                ip->i_flag |= IN_ACCESS;
                }
                ufs_itimes(vp);
                if (vap->va_mtime.tv_nsec != VNOVAL) {
                        DIP_ASSIGN(ip, mtime, vap->va_mtime.tv_sec);
                        DIP_ASSIGN(ip, mtimensec, vap->va_mtime.tv_nsec);
                }
                if (vap->va_atime.tv_nsec != VNOVAL) {
                        DIP_ASSIGN(ip, atime, vap->va_atime.tv_sec);
                        DIP_ASSIGN(ip, atimensec, vap->va_atime.tv_nsec);
                }
                error = UFS_UPDATE(ip, 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, hint);
        return (error);
}

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

        if (cred->cr_uid != DIP(ip, uid) &&
            !vnoperm(vp) &&
            (error = suser_ucred(cred)))
                return (error);
        if (cred->cr_uid && !vnoperm(vp)) {
                if (vp->v_type != VDIR && (mode & S_ISTXT))
                        return (EFTYPE);
                if (!groupmember(DIP(ip, gid), cred) && (mode & ISGID))
                        return (EPERM);
        }
        DIP_AND(ip, mode, ~ALLPERMS);
        DIP_OR(ip, mode, mode & ALLPERMS);
        ip->i_flag |= IN_CHANGE;
        if ((vp->v_flag & VTEXT) && (DIP(ip, mode) & S_ISTXT) == 0)
                (void) uvm_vnp_uncache(vp);
        return (0);
}

/*
 * Perform chown operation on inode ip;
 * inode must be locked prior to call.
 */
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;
        daddr_t change;
        enum ufs_quota_flags quota_flags = 0;

        if (uid == (uid_t)VNOVAL)
                uid = DIP(ip, uid);
        if (gid == (gid_t)VNOVAL)
                gid = DIP(ip, 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 != DIP(ip, uid) || uid != DIP(ip, uid) ||
            (gid != DIP(ip, gid) && !groupmember(gid, cred))) &&
            !vnoperm(vp) &&
            (error = suser_ucred(cred)))
                return (error);
        ogid = DIP(ip, gid);
        ouid = DIP(ip, uid);
        change = DIP(ip, blocks);

        if (ouid == uid)
                quota_flags |= UFS_QUOTA_NOUID;
        
        if (ogid == gid)
                quota_flags |= UFS_QUOTA_NOGID;

        if ((error = getinoquota(ip)) != 0)
                return (error);
        (void) ufs_quota_free_blocks2(ip, change, cred, quota_flags);
        (void) ufs_quota_free_inode2(ip, cred, quota_flags);
        (void) ufs_quota_delete(ip);

        DIP_ASSIGN(ip, gid, gid);
        DIP_ASSIGN(ip, uid, uid);

        if ((error = getinoquota(ip)) != 0)
                goto error;

        if ((error = ufs_quota_alloc_blocks2(ip, change, cred, 
                 quota_flags)) != 0) 
                goto error;

        if ((error = ufs_quota_alloc_inode2(ip, cred ,
                 quota_flags)) != 0) {
                (void)ufs_quota_free_blocks2(ip, change, cred, 
                    quota_flags);               
                goto error;
        }

        if (getinoquota(ip))
                panic("chown: lost quota");

        if (ouid != uid || ogid != gid)
                ip->i_flag |= IN_CHANGE;
        if (!vnoperm(vp)) {
                if (ouid != uid && cred->cr_uid != 0)
                        DIP_AND(ip, mode, ~ISUID);
                if (ogid != gid && cred->cr_uid != 0)
                        DIP_AND(ip, mode, ~ISGID);
        }
        return (0);

error:
        (void) ufs_quota_delete(ip);

        DIP_ASSIGN(ip, gid, ogid);
        DIP_ASSIGN(ip, uid, ouid);

        if (getinoquota(ip) == 0) {
                (void) ufs_quota_alloc_blocks2(ip, change, cred, 
                    quota_flags | UFS_QUOTA_FORCE);
                (void) ufs_quota_alloc_inode2(ip, cred,
                    quota_flags | UFS_QUOTA_FORCE);
                (void) getinoquota(ip);
        }
        return (error);

}

int
ufs_ioctl(void *v)
{
#if 0
        struct vop_ioctl_args *ap = v;
#endif
        return (ENOTTY);
}

int
ufs_remove(void *v)
{
        struct vop_remove_args *ap = v;
        struct inode *ip;
        struct vnode *vp = ap->a_vp;
        struct vnode *dvp = ap->a_dvp;
        int error;

        ip = VTOI(vp);
        if (vp->v_type == VDIR || (DIP(ip, flags) & (IMMUTABLE | APPEND)) ||
            (DIP(VTOI(dvp), flags) & APPEND)) {
                error = EPERM;
                goto out;
        }
        error = ufs_dirremove(dvp, ip, ap->a_cnp->cn_flags, 0);
        VN_KNOTE(vp, NOTE_DELETE);
        VN_KNOTE(dvp, NOTE_WRITE);
 out:
        return (error);
}

/*
 * link vnode call
 */
int
ufs_link(void *v)
{
        struct vop_link_args *ap = v;
        struct vnode *dvp = ap->a_dvp;
        struct vnode *vp = ap->a_vp;
        struct componentname *cnp = ap->a_cnp;
        struct inode *ip;
        struct direct newdir;
        int error;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ufs_link: no name");
#endif
        if (dvp != vp && (error = vn_lock(vp, LK_EXCLUSIVE))) {
                VOP_ABORTOP(dvp, cnp);
                goto out2;
        }
        ip = VTOI(vp);
        if ((nlink_t) DIP(ip, nlink) >= LINK_MAX) {
                VOP_ABORTOP(dvp, cnp);
                error = EMLINK;
                goto out1;
        }
        if (DIP(ip, flags) & (IMMUTABLE | APPEND)) {
                VOP_ABORTOP(dvp, cnp);
                error = EPERM;
                goto out1;
        }
        ip->i_effnlink++;
        DIP_ADD(ip, nlink, 1);
        ip->i_flag |= IN_CHANGE;
        if ((error = UFS_UPDATE(ip, 1)) == 0) {
                ufs_makedirentry(ip, cnp, &newdir);
                error = ufs_direnter(dvp, vp, &newdir, cnp, NULL);
        }
        if (error) {
                ip->i_effnlink--;
                DIP_ADD(ip, nlink, -1);
                ip->i_flag |= IN_CHANGE;
        }
        pool_put(&namei_pool, cnp->cn_pnbuf);
        VN_KNOTE(vp, NOTE_LINK);
        VN_KNOTE(dvp, NOTE_WRITE);
out1:
        if (dvp != vp)
                VOP_UNLOCK(vp);
out2:
        vput(dvp);
        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(void *v)
{
        struct vop_rename_args *ap = v;
        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;
        int doingdirectory = 0, oldparent = 0, newparent = 0;
        int error = 0;

#ifdef DIAGNOSTIC
        if ((tcnp->cn_flags & HASBUF) == 0 ||
            (fcnp->cn_flags & HASBUF) == 0)
                panic("ufs_rename: no name");
#endif
        /*
         * Check for cross-device rename.
         */
        if ((fvp->v_mount != tdvp->v_mount) ||
            (tvp && (fvp->v_mount != tvp->v_mount))) {
                error = EXDEV;
abortit:
                VOP_ABORTOP(tdvp, tcnp);
                if (tdvp == tvp)
                        vrele(tdvp);
                else
                        vput(tdvp);
                if (tvp)
                        vput(tvp);
                VOP_ABORTOP(fdvp, fcnp);
                vrele(fdvp);
                vrele(fvp);
                return (error);
        }

        if (tvp && ((DIP(VTOI(tvp), flags) & (IMMUTABLE | APPEND)) ||
            (DIP(VTOI(tdvp), flags) & APPEND))) {
                error = EPERM;
                goto abortit;
        }

        /*
         * 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.
                         */
                        error = ENOENT;
                        goto abortit;
                }

                /* Release destination completely. */
                VOP_ABORTOP(tdvp, tcnp);
                vput(tdvp);
                vput(tvp);

                /*
                 * Delete source.  There is another race now that everything
                 * is unlocked, but this doesn't cause any new complications.
                 * relookup() may find a file that is unrelated to the
                 * original one, or it may fail.  Too bad.
                 */
                vrele(fvp);
                fcnp->cn_flags &= ~MODMASK;
                fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
                if ((fcnp->cn_flags & SAVESTART) == 0)
                        panic("ufs_rename: lost from startdir");
                fcnp->cn_nameiop = DELETE;
                if ((error = vfs_relookup(fdvp, &fvp, fcnp)) != 0)
                        return (error);         /* relookup did vrele() */
                vrele(fdvp);
                return (VOP_REMOVE(fdvp, fvp, fcnp));
        }

        if ((error = vn_lock(fvp, LK_EXCLUSIVE)) != 0)
                goto abortit;

        /* fvp, tdvp, tvp now locked */
        dp = VTOI(fdvp);
        ip = VTOI(fvp);
        if ((nlink_t) DIP(ip, nlink) >= LINK_MAX) {
                VOP_UNLOCK(fvp);
                error = EMLINK;
                goto abortit;
        }
        if ((DIP(ip, flags) & (IMMUTABLE | APPEND)) ||
            (DIP(dp, flags) & APPEND)) {
                VOP_UNLOCK(fvp);
                error = EPERM;
                goto abortit;
        }
        if ((DIP(ip, mode) & IFMT) == IFDIR) {
                error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
                if (!error && tvp)
                        error = VOP_ACCESS(tvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
                if (error) {
                        VOP_UNLOCK(fvp);
                        error = EACCES;
                        goto abortit;
                }
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
                    dp == ip ||
                    (fcnp->cn_flags & ISDOTDOT) ||
                    (tcnp->cn_flags & ISDOTDOT) ||
                    (ip->i_flag & IN_RENAME)) {
                        VOP_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? */

        /*
         * 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_effnlink++;
        DIP_ADD(ip, nlink, 1);
        ip->i_flag |= IN_CHANGE;
        if ((error = UFS_UPDATE(ip, 1)) != 0) {
                VOP_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 hierarchy 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_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
        VOP_UNLOCK(fvp);

        /* tdvp and tvp locked */
        if (oldparent != dp->i_number)
                newparent = dp->i_number;
        if (doingdirectory && newparent) {
                if (error)      /* write access check above */
                        goto bad;
                if (xp != NULL)
                        vput(tvp);
                /*
                 * Compensate for the reference ufs_checkpath() loses.
                 */
                vref(tdvp);
                /* Only tdvp is locked */
                if ((error = ufs_checkpath(ip, dp, tcnp->cn_cred)) != 0) {
                        vrele(tdvp);
                        goto out;
                }
                if ((tcnp->cn_flags & SAVESTART) == 0)
                        panic("ufs_rename: lost to startdir");
                if ((error = vfs_relookup(tdvp, &tvp, tcnp)) != 0)
                        goto out;
                vrele(tdvp); /* relookup() acquired a reference */
                dp = VTOI(tdvp);
                xp = NULL;
                if (tvp)
                        xp = VTOI(tvp);
        }
        /*
         * 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) DIP(dp, nlink) >= LINK_MAX) {
                                error = EMLINK;
                                goto bad;
                        }
                        dp->i_effnlink++;
                        DIP_ADD(dp, nlink, 1);
                        dp->i_flag |= IN_CHANGE;
                        if ((error = UFS_UPDATE(dp, 1)) 
                            != 0) {
                                dp->i_effnlink--;
                                DIP_ADD(dp, nlink, -1);
                                dp->i_flag |= IN_CHANGE;
                                goto bad;
                        }
                }
                ufs_makedirentry(ip, tcnp, &newdir);
                if ((error = ufs_direnter(tdvp, NULL, &newdir, tcnp, NULL)) != 0) {
                        if (doingdirectory && newparent) {
                                dp->i_effnlink--;
                                DIP_ADD(dp, nlink, -1);
                                dp->i_flag |= IN_CHANGE;
                                (void)UFS_UPDATE(dp, 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("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 ((DIP(dp, mode) & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
                    tcnp->cn_cred->cr_uid != DIP(dp, uid) &&
                    DIP(xp, uid )!= tcnp->cn_cred->cr_uid &&
                    !vnoperm(tdvp)) {
                        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).
                 */
                if ((DIP(xp, 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(tdvp);
                } else if (doingdirectory) {
                        error = EISDIR;
                        goto bad;
                }

                if ((error = ufs_dirrewrite(dp, xp, ip->i_number,
                    IFTODT(DIP(ip, mode)), (doingdirectory && newparent) ?
                    newparent : doingdirectory)) != 0)
                        goto bad;
                if (doingdirectory) {
                        if (!newparent) {
                                dp->i_effnlink--;
                        }
                        xp->i_effnlink--;
                }
                if (doingdirectory) {
                        /*
                        * 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) {
                                DIP_ADD(dp, nlink, -1);
                                dp->i_flag |= IN_CHANGE;
                        }

                        DIP_ADD(xp, nlink, -1);
                        xp->i_flag |= IN_CHANGE;
                        if ((error = UFS_TRUNCATE(VTOI(tvp), (off_t)0, IO_SYNC,
                            tcnp->cn_cred)) != 0)
                                goto bad;
                }
                VN_KNOTE(tdvp, NOTE_WRITE);
                vput(tdvp);
                VN_KNOTE(tvp, NOTE_DELETE);
                vput(tvp);
                xp = NULL;
        }

        /*
         * 3) Unlink the source.
         */
        fcnp->cn_flags &= ~MODMASK;
        fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
        if ((fcnp->cn_flags & SAVESTART) == 0)
                panic("ufs_rename: lost from startdir");
        if ((error = vfs_relookup(fdvp, &fvp, fcnp)) != 0) {
                vrele(ap->a_fvp);
                return (error);
        }
        vrele(fdvp);
        if (fvp == NULL) {
                /*
                 * From name has disappeared.
                 */
                if (doingdirectory)
                        panic("ufs_rename: lost dir entry");
                vrele(ap->a_fvp);
                return (0);
        }

        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.
         */
        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(fdvp);
                }
                error = ufs_dirremove(fdvp, xp, fcnp->cn_flags, 0);
                xp->i_flag &= ~IN_RENAME;
        }
        VN_KNOTE(fvp, NOTE_RENAME);
        if (dp)
                vput(fdvp);
        if (xp)
                vput(fvp);
        vrele(ap->a_fvp);
        return (error);

bad:
        if (xp)
                vput(ITOV(xp));
        vput(ITOV(dp));
out:
        vrele(fdvp);
        if (doingdirectory)
                ip->i_flag &= ~IN_RENAME;
        if (vn_lock(fvp, LK_EXCLUSIVE) == 0) {
                ip->i_effnlink--;
                DIP_ADD(ip, nlink, -1);
                ip->i_flag |= IN_CHANGE;
                ip->i_flag &= ~IN_RENAME;
                vput(fvp);
        } else
                vrele(fvp);
        return (error);
}

/*
 * Mkdir system call
 */
int
ufs_mkdir(void *v)
{
        struct vop_mkdir_args *ap = v;
        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 direct newdir;
        struct dirtemplate dirtemplate;
        int error, dmode;

#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ufs_mkdir: no name");
#endif
        dp = VTOI(dvp);
        if ((nlink_t) DIP(dp, 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 = UFS_INODE_ALLOC(dp, dmode, cnp->cn_cred, &tvp)) != 0)
                goto out;

        ip = VTOI(tvp);

        DIP_ASSIGN(ip, uid, cnp->cn_cred->cr_uid);
        DIP_ASSIGN(ip, gid, DIP(dp, gid));

        if ((error = getinoquota(ip)) ||
            (error = ufs_quota_alloc_inode(ip, cnp->cn_cred))) {
                pool_put(&namei_pool, cnp->cn_pnbuf);
                UFS_INODE_FREE(ip, ip->i_number, dmode);
                vput(tvp);
                vput(dvp);
                return (error);
        }

        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        DIP_ASSIGN(ip, mode, dmode);
        tvp->v_type = VDIR;     /* Rest init'd in getnewvnode(). */
        ip->i_effnlink = 2;
        DIP_ASSIGN(ip, nlink, 2);

        /*
         * Bump link count in parent directory to reflect work done below.
         * Should be done before reference is create so cleanup is 
         * possible if we crash.
         */
        dp->i_effnlink++;
        DIP_ADD(dp, nlink, 1);
        dp->i_flag |= IN_CHANGE;
        if ((error = UFS_UPDATE(dp, 1)) != 0)
                goto bad;

        /* 
         * Initialize directory with "." and ".." from static template.
         */
        dirtemplate = mastertemplate;
        dirtemplate.dot_ino = ip->i_number;
        dirtemplate.dotdot_ino = dp->i_number;

        if ((error = UFS_BUF_ALLOC(ip, (off_t)0, DIRBLKSIZ, cnp->cn_cred,
            B_CLRBUF, &bp)) != 0)
                goto bad;
        DIP_ASSIGN(ip, size, DIRBLKSIZ);
        ip->i_flag |= IN_CHANGE | IN_UPDATE;
        uvm_vnp_setsize(tvp, DIP(ip, size));
        memcpy(bp->b_data, &dirtemplate, sizeof(dirtemplate));
        if ((error = UFS_UPDATE(ip, 1)) != 0) {
                (void)VOP_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 ((error = VOP_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--;
                DIP_ADD(dp, nlink, -1);
                dp->i_flag |= IN_CHANGE;
                /*
                 * 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;
                DIP_ASSIGN(ip, nlink, 0);
                ip->i_flag |= IN_CHANGE;
                vput(tvp);
        }
out:
        pool_put(&namei_pool, cnp->cn_pnbuf);
        vput(dvp);

        return (error);
}

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

        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.
         */
        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 ((DIP(dp, flags) & APPEND) ||
                (DIP(ip, flags) & (IMMUTABLE | APPEND))) {
                error = EPERM;
                goto out;
        }
        /*
         * 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 ((error = ufs_dirremove(dvp, ip, cnp->cn_flags, 1)) != 0) {
                dp->i_effnlink++;
                ip->i_effnlink++;
                goto out;
        }

        VN_KNOTE(dvp, NOTE_WRITE | NOTE_LINK);
        cache_purge(dvp);
        /*
         * Truncate inode. The only stuff left in the directory is "." and
         * "..". The "." reference is inconsequential since we are quashing
         * it.
         */
        DIP_ADD(dp, nlink, -1);
        dp->i_flag |= IN_CHANGE;
        DIP_ADD(ip, nlink, -1);
        ip->i_flag |= IN_CHANGE;
        error = UFS_TRUNCATE(ip, (off_t)0, DOINGASYNC(vp) ? 0 : IO_SYNC,
            cnp->cn_cred);

        cache_purge(vp);
#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);
        vput(dvp);
        vput(vp);
        return (error);
}

/*
 * symlink -- make a symbolic link
 */
int
ufs_symlink(void *v)
{
        struct vop_symlink_args *ap = v;
        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) {
                vput(ap->a_dvp);
                return (error);
        }
        VN_KNOTE(ap->a_dvp, NOTE_WRITE);
        vput(ap->a_dvp);
        vp = *vpp;
        ip = VTOI(vp);
        len = strlen(ap->a_target);
        if (len < ip->i_ump->um_maxsymlinklen) {
                memcpy(SHORTLINK(ip), ap->a_target, len);
                DIP_ASSIGN(ip, size, len);
                ip->i_flag |= IN_CHANGE | IN_UPDATE;
        } else
                error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
                    UIO_SYSSPACE, IO_NODELOCKED, ap->a_cnp->cn_cred, NULL,
                    curproc);
        vput(vp);
        return (error);
}

/*
 * Vnode op for reading directories.
 * 
 * This routine converts the on-disk struct direct entries to the
 * struct dirent entries expected by userland and the rest of the kernel.
 */
int
ufs_readdir(void *v)
{
        struct vop_readdir_args *ap = v;
        struct uio auio, *uio = ap->a_uio;
        struct iovec aiov;
        union {
                struct  dirent dn;
                char __pad[roundup(sizeof(struct dirent), 8)];
        } u;
        off_t off = uio->uio_offset;
        struct direct *dp;
        char *edp;
        caddr_t diskbuf;
        size_t count, entries;
        int bufsize, readcnt, error;

        if (uio->uio_rw != UIO_READ)
                return (EINVAL);

        count = uio->uio_resid;
        entries = (uio->uio_offset + count) & (DIRBLKSIZ - 1);

        /* Make sure we don't return partial entries. */
        if (count <= entries)
                return (EINVAL);

        /*
         * Convert and copy back the on-disk struct direct format to
         * the user-space struct dirent format, one entry at a time
         */

        /* read from disk, stopping on a block boundary, max 64kB */
        readcnt = min(count, 64*1024) - entries;

        auio = *uio;
        auio.uio_iov = &aiov;
        auio.uio_iovcnt = 1;
        auio.uio_resid = readcnt;
        auio.uio_segflg = UIO_SYSSPACE;
        aiov.iov_len = readcnt;
        bufsize = readcnt;
        diskbuf = malloc(bufsize, M_TEMP, M_WAITOK);
        aiov.iov_base = diskbuf;
        error = VOP_READ(ap->a_vp, &auio, 0, ap->a_cred);
        readcnt -= auio.uio_resid;
        dp = (struct direct *)diskbuf;
        edp = &diskbuf[readcnt];

        memset(&u, 0, sizeof(u));

        /*
         * While
         *  - we haven't failed to VOP_READ or uiomove()
         *  - there's space in the read buf for the head of an entry
         *  - that entry has a valid d_reclen, and
         *  - there's space for the *entire* entry
         * then we're good to process this one.
         */
        while (error == 0 &&
            (char *)dp + offsetof(struct direct, d_name) < edp &&
            dp->d_reclen > offsetof(struct direct, d_name) &&
            (char *)dp + dp->d_reclen <= edp) {
                u.dn.d_reclen = roundup(dp->d_namlen+1 +
                    offsetof(struct dirent, d_name), 8);
                if (u.dn.d_reclen > uio->uio_resid)
                        break;
                off += dp->d_reclen;
                u.dn.d_off = off;
                u.dn.d_fileno = dp->d_ino;
                u.dn.d_type = dp->d_type;
                u.dn.d_namlen = dp->d_namlen;
                memcpy(u.dn.d_name, dp->d_name, u.dn.d_namlen);
                memset(u.dn.d_name + u.dn.d_namlen, 0, u.dn.d_reclen
                    - u.dn.d_namlen - offsetof(struct dirent, d_name));

                if (memchr(u.dn.d_name, '/', u.dn.d_namlen) != NULL) {
                        error = EINVAL;
                        break;
                }

                error = uiomove(&u.dn, u.dn.d_reclen, uio);
                dp = (struct direct *)((char *)dp + dp->d_reclen);
        }

        /*
         * If there was room for an entry in what we read but its
         * d_reclen is bogus, fail
         */
        if ((char *)dp + offsetof(struct direct, d_name) < edp &&
            dp->d_reclen <= offsetof(struct direct, d_name))
                error = EIO;
        free(diskbuf, M_TEMP, bufsize);

        uio->uio_offset = off;
        *ap->a_eofflag = DIP(VTOI(ap->a_vp), size) <= off;

        return (error);
}

/*
 * Return target name of a symbolic link
 */
int
ufs_readlink(void *v)
{
        struct vop_readlink_args *ap = v;
        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);
        u_int64_t isize;

        isize = DIP(ip, size);
        if (isize < ip->i_ump->um_maxsymlinklen)
                return (uiomove((char *)SHORTLINK(ip), isize, ap->a_uio));
        return (VOP_READ(vp, ap->a_uio, 0, ap->a_cred));
}

/*
 * Lock an inode. If its already locked, set the WANT bit and sleep.
 */
int
ufs_lock(void *v)
{
        struct vop_lock_args *ap = v;
        struct vnode *vp = ap->a_vp;

        return rrw_enter(&VTOI(vp)->i_lock, ap->a_flags & LK_RWFLAGS);
}

/*
 * Unlock an inode.  If WANT bit is on, wakeup.
 */
int
ufs_unlock(void *v)
{
        struct vop_unlock_args *ap = v;
        struct vnode *vp = ap->a_vp;

        rrw_exit(&VTOI(vp)->i_lock);
        return 0;
}

/*
 * Check for a locked inode.
 */
int
ufs_islocked(void *v)
{
        struct vop_islocked_args *ap = v;

        return rrw_status(&VTOI(ap->a_vp)->i_lock);
}

/*
 * Calculate the logical to physical mapping if not done already,
 * then call the device strategy routine.
 */
int
ufs_strategy(void *v)
{
        struct vop_strategy_args *ap = v;
        struct buf *bp = ap->a_bp;
        struct vnode *vp = bp->b_vp;
        struct inode *ip;
        int error;
        int s;

        ip = VTOI(vp);
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                panic("ufs_strategy: spec");
        if (bp->b_blkno == bp->b_lblkno) {
                error = VOP_BMAP(vp, bp->b_lblkno, NULL, &bp->b_blkno,
                                 NULL);
                if (error) {
                        bp->b_error = error;
                        bp->b_flags |= B_ERROR;
                        s = splbio();
                        biodone(bp);
                        splx(s);
                        return (error);
                }
                if (bp->b_blkno == -1)
                        clrbuf(bp);
        }
        if (bp->b_blkno == -1) {
                s = splbio();
                biodone(bp);
                splx(s);
                return (0);
        }
        vp = ip->i_devvp;
        bp->b_dev = vp->v_rdev;
        VOP_STRATEGY(vp, bp);
        return (0);
}

/*
 * Print out the contents of an inode.
 */
int
ufs_print(void *v)
{
#if defined(DEBUG) || defined(DIAGNOSTIC) || defined(VFSLCKDEBUG)
        struct vop_print_args *ap = v;

        struct vnode *vp = ap->a_vp;
        struct inode *ip = VTOI(vp);

        printf("tag VT_UFS, ino %u, on dev %d, %d", ip->i_number,
                major(ip->i_dev), minor(ip->i_dev));
        printf(" flags 0x%x, effnlink %d, nlink %d\n",
           ip->i_flag, ip->i_effnlink, DIP(ip, nlink));
        printf("\tmode 0%o, owner %d, group %d, size %lld",
            DIP(ip, mode), DIP(ip, uid), DIP(ip, gid), DIP(ip, size));

#ifdef FIFO
        if (vp->v_type == VFIFO)
                fifo_printinfo(vp);
#endif /* FIFO */
        printf("\n");
#endif

        return (0);
}

/*
 * Read wrapper for special devices.
 */
int
ufsspec_read(void *v)
{
        struct vop_read_args *ap = v;

        /*
         * Set access flag.
         */
        VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (spec_read(ap));
}

/*
 * Write wrapper for special devices.
 */
int
ufsspec_write(void *v)
{
        struct vop_write_args *ap = v;

        /*
         * Set update and change flags.
         */
        VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (spec_write(ap));
}

/*
 * Close wrapper for special devices.
 *
 * Update the times on the inode then do device close.
 */
int
ufsspec_close(void *v)
{
        struct vop_close_args *ap = v;
        struct vnode *vp = ap->a_vp;

        if (vp->v_usecount > 1)
                ufs_itimes(vp);
        return (spec_close(ap));
}

#ifdef FIFO
/*
 * Read wrapper for fifo's
 */
int
ufsfifo_read(void *v)
{
        struct vop_read_args *ap = v;

        /*
         * Set access flag.
         */
        VTOI(ap->a_vp)->i_flag |= IN_ACCESS;
        return (fifo_read(ap));
}

/*
 * Write wrapper for fifo's.
 */
int
ufsfifo_write(void *v)
{
        struct vop_write_args *ap = v;

        /*
         * Set update and change flags.
         */
        VTOI(ap->a_vp)->i_flag |= IN_CHANGE | IN_UPDATE;
        return (fifo_write(ap));
}

/*
 * Close wrapper for fifo's.
 *
 * Update the times on the inode then do device close.
 */
int
ufsfifo_close(void *v)
{
        struct vop_close_args *ap = v;
        struct vnode *vp = ap->a_vp;

        if (vp->v_usecount > 1)
                ufs_itimes(vp);
        return (fifo_close(ap));
}
#endif /* FIFO */

/*
 * Return POSIX pathconf information applicable to ufs filesystems.
 */
int
ufs_pathconf(void *v)
{
        struct vop_pathconf_args *ap = v;
        int error = 0;

        switch (ap->a_name) {
        case _PC_LINK_MAX:
                *ap->a_retval = LINK_MAX;
                break;
        case _PC_NAME_MAX:
                *ap->a_retval = NAME_MAX;
                break;
        case _PC_CHOWN_RESTRICTED:
                *ap->a_retval = 1;
                break;
        case _PC_NO_TRUNC:
                *ap->a_retval = 1;
                break;
        case _PC_ALLOC_SIZE_MIN:
                *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_bsize;
                break;
        case _PC_FILESIZEBITS:
                *ap->a_retval = 64;
                break;
        case _PC_REC_INCR_XFER_SIZE:
                *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
                break;
        case _PC_REC_MAX_XFER_SIZE:
                *ap->a_retval = -1; /* means ``unlimited'' */
                break;
        case _PC_REC_MIN_XFER_SIZE:
                *ap->a_retval = ap->a_vp->v_mount->mnt_stat.f_iosize;
                break;
        case _PC_REC_XFER_ALIGN:
                *ap->a_retval = PAGE_SIZE;
                break;
        case _PC_SYMLINK_MAX:
                *ap->a_retval = MAXPATHLEN;
                break;
        case _PC_2_SYMLINKS:
                *ap->a_retval = 1;
                break;
        case _PC_TIMESTAMP_RESOLUTION:
                *ap->a_retval = 1;
                break;
        default:
                error = EINVAL;
                break;
        }

        return (error);
}

/*
 * Advisory record locking support
 */
int
ufs_advlock(void *v)
{
        struct vop_advlock_args *ap = v;
        struct inode *ip = VTOI(ap->a_vp);

        return (lf_advlock(&ip->i_lockf, DIP(ip, size), ap->a_id, ap->a_op,
            ap->a_fl, ap->a_flags));
}

/*
 * Allocate a new inode.
 */
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);
#ifdef DIAGNOSTIC
        if ((cnp->cn_flags & HASBUF) == 0)
                panic("ufs_makeinode: no name");
#endif
        *vpp = NULL;
        if ((mode & IFMT) == 0)
                mode |= IFREG;

        if ((error = UFS_INODE_ALLOC(pdir, mode, cnp->cn_cred, &tvp)) != 0) {
                pool_put(&namei_pool, cnp->cn_pnbuf);
                return (error);
        }

        ip = VTOI(tvp);

        DIP_ASSIGN(ip, gid, DIP(pdir, gid));
        DIP_ASSIGN(ip, uid, cnp->cn_cred->cr_uid);

        if ((error = getinoquota(ip)) ||
            (error = ufs_quota_alloc_inode(ip, cnp->cn_cred))) {
                pool_put(&namei_pool, cnp->cn_pnbuf);
                UFS_INODE_FREE(ip, ip->i_number, mode);
                vput(tvp);
                return (error);
        }

        ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
        DIP_ASSIGN(ip, mode, mode);
        tvp->v_type = IFTOVT(mode);     /* Rest init'd in getnewvnode(). */
        ip->i_effnlink = 1;
        DIP_ASSIGN(ip, nlink, 1);
        if ((DIP(ip, mode) & ISGID) &&
                !groupmember(DIP(ip, gid), cnp->cn_cred) &&
            !vnoperm(dvp) &&
            suser_ucred(cnp->cn_cred))
                DIP_AND(ip, mode, ~ISGID);

        /*
         * Make sure inode goes to disk before directory entry.
         */
        if ((error = UFS_UPDATE(ip, 1)) != 0)
                goto bad;

        ufs_makedirentry(ip, cnp, &newdir);
        if ((error = ufs_direnter(dvp, tvp, &newdir, cnp, NULL)) != 0)
                goto bad;

        if ((cnp->cn_flags & SAVESTART) == 0)
                pool_put(&namei_pool, cnp->cn_pnbuf);
        *vpp = tvp;
        return (0);

bad:
        /*
         * Write error occurred trying to update the inode
         * or the directory so must deallocate the inode.
         */
        pool_put(&namei_pool, cnp->cn_pnbuf);
        ip->i_effnlink = 0;
        DIP_ASSIGN(ip, nlink, 0);
        ip->i_flag |= IN_CHANGE;
        tvp->v_type = VNON;
        vput(tvp);

        return (error);
}

const struct filterops ufsread_filtops = {
        .f_flags        = FILTEROP_ISFD,
        .f_attach       = NULL,
        .f_detach       = filt_ufsdetach,
        .f_event        = filt_ufsread,
};

const struct filterops ufswrite_filtops = {
        .f_flags        = FILTEROP_ISFD,
        .f_attach       = NULL,
        .f_detach       = filt_ufsdetach,
        .f_event        = filt_ufswrite,
};

const struct filterops ufsvnode_filtops = {
        .f_flags        = FILTEROP_ISFD,
        .f_attach       = NULL,
        .f_detach       = filt_ufsdetach,
        .f_event        = filt_ufsvnode,
};

int
ufs_kqfilter(void *v)
{
        struct vop_kqfilter_args *ap = v;
        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 (EINVAL);
        }

        kn->kn_hook = (caddr_t)vp;

        klist_insert_locked(&vp->v_klist, kn);

        return (0);
}

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

        klist_remove_locked(&vp->v_klist, kn);
}

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

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

#ifdef EXT2FS
        if (IS_EXT2_VNODE(ip->i_vnode))
                kn->kn_data = ext2fs_size(ip) - foffset(kn->kn_fp);
        else
#endif
                kn->kn_data = DIP(ip, size) - foffset(kn->kn_fp);
        if (kn->kn_data == 0 && kn->kn_sfflags & NOTE_EOF) {
                kn->kn_fflags |= NOTE_EOF;
                return (1);
        }

        if (kn->kn_flags & (__EV_POLL | __EV_SELECT))
                return (1);

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

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_ONESHOT);
                return (1);
        }

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

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;
                return (1);
        }
        return (kn->kn_fflags != 0);
}