This commit was generated by cvs2svn to compensate for changes in r1541,

which included commits to RCS files with non-trunk default branches.

39 files changed, 13713 insertions, 0 deletions

diff --git a/sys/miscfs/deadfs/dead_vnops.c b/sys/miscfs/deadfs/dead_vnops.c
new file mode 100644
index 0000000..9d04652
--- /dev/null
+++ b/sys/miscfs/deadfs/dead_vnops.c
@@ -0,0 +1,354 @@
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ *
+ *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/vnode.h>
+#include <sys/errno.h>
+#include <sys/namei.h>
+#include <sys/buf.h>
+
+/*
+ * Prototypes for dead operations on vnodes.
+ */
+int	dead_badop(),
+	dead_ebadf();
+int	dead_lookup __P((struct vop_lookup_args *));
+#define dead_create ((int (*) __P((struct  vop_create_args *)))dead_badop)
+#define dead_mknod ((int (*) __P((struct  vop_mknod_args *)))dead_badop)
+int	dead_open __P((struct vop_open_args *));
+#define dead_close ((int (*) __P((struct  vop_close_args *)))nullop)
+#define dead_access ((int (*) __P((struct  vop_access_args *)))dead_ebadf)
+#define dead_getattr ((int (*) __P((struct  vop_getattr_args *)))dead_ebadf)
+#define dead_setattr ((int (*) __P((struct  vop_setattr_args *)))dead_ebadf)
+int	dead_read __P((struct vop_read_args *));
+int	dead_write __P((struct vop_write_args *));
+int	dead_ioctl __P((struct vop_ioctl_args *));
+int	dead_select __P((struct vop_select_args *));
+#define dead_mmap ((int (*) __P((struct  vop_mmap_args *)))dead_badop)
+#define dead_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
+#define dead_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
+#define dead_remove ((int (*) __P((struct  vop_remove_args *)))dead_badop)
+#define dead_link ((int (*) __P((struct  vop_link_args *)))dead_badop)
+#define dead_rename ((int (*) __P((struct  vop_rename_args *)))dead_badop)
+#define dead_mkdir ((int (*) __P((struct  vop_mkdir_args *)))dead_badop)
+#define dead_rmdir ((int (*) __P((struct  vop_rmdir_args *)))dead_badop)
+#define dead_symlink ((int (*) __P((struct  vop_symlink_args *)))dead_badop)
+#define dead_readdir ((int (*) __P((struct  vop_readdir_args *)))dead_ebadf)
+#define dead_readlink ((int (*) __P((struct  vop_readlink_args *)))dead_ebadf)
+#define dead_abortop ((int (*) __P((struct  vop_abortop_args *)))dead_badop)
+#define dead_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
+#define dead_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
+int	dead_lock __P((struct vop_lock_args *));
+#define dead_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
+int	dead_bmap __P((struct vop_bmap_args *));
+int	dead_strategy __P((struct vop_strategy_args *));
+int	dead_print __P((struct vop_print_args *));
+#define dead_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+#define dead_pathconf ((int (*) __P((struct  vop_pathconf_args *)))dead_ebadf)
+#define dead_advlock ((int (*) __P((struct  vop_advlock_args *)))dead_ebadf)
+#define dead_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))dead_badop)
+#define dead_valloc ((int (*) __P((struct  vop_valloc_args *)))dead_badop)
+#define dead_vfree ((int (*) __P((struct  vop_vfree_args *)))dead_badop)
+#define dead_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
+#define dead_update ((int (*) __P((struct  vop_update_args *)))nullop)
+#define dead_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
+
+int (**dead_vnodeop_p)();
+struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, dead_lookup },	/* lookup */
+	{ &vop_create_desc, dead_create },	/* create */
+	{ &vop_mknod_desc, dead_mknod },	/* mknod */
+	{ &vop_open_desc, dead_open },	/* open */
+	{ &vop_close_desc, dead_close },	/* close */
+	{ &vop_access_desc, dead_access },	/* access */
+	{ &vop_getattr_desc, dead_getattr },	/* getattr */
+	{ &vop_setattr_desc, dead_setattr },	/* setattr */
+	{ &vop_read_desc, dead_read },	/* read */
+	{ &vop_write_desc, dead_write },	/* write */
+	{ &vop_ioctl_desc, dead_ioctl },	/* ioctl */
+	{ &vop_select_desc, dead_select },	/* select */
+	{ &vop_mmap_desc, dead_mmap },	/* mmap */
+	{ &vop_fsync_desc, dead_fsync },	/* fsync */
+	{ &vop_seek_desc, dead_seek },	/* seek */
+	{ &vop_remove_desc, dead_remove },	/* remove */
+	{ &vop_link_desc, dead_link },	/* link */
+	{ &vop_rename_desc, dead_rename },	/* rename */
+	{ &vop_mkdir_desc, dead_mkdir },	/* mkdir */
+	{ &vop_rmdir_desc, dead_rmdir },	/* rmdir */
+	{ &vop_symlink_desc, dead_symlink },	/* symlink */
+	{ &vop_readdir_desc, dead_readdir },	/* readdir */
+	{ &vop_readlink_desc, dead_readlink },	/* readlink */
+	{ &vop_abortop_desc, dead_abortop },	/* abortop */
+	{ &vop_inactive_desc, dead_inactive },	/* inactive */
+	{ &vop_reclaim_desc, dead_reclaim },	/* reclaim */
+	{ &vop_lock_desc, dead_lock },	/* lock */
+	{ &vop_unlock_desc, dead_unlock },	/* unlock */
+	{ &vop_bmap_desc, dead_bmap },	/* bmap */
+	{ &vop_strategy_desc, dead_strategy },	/* strategy */
+	{ &vop_print_desc, dead_print },	/* print */
+	{ &vop_islocked_desc, dead_islocked },	/* islocked */
+	{ &vop_pathconf_desc, dead_pathconf },	/* pathconf */
+	{ &vop_advlock_desc, dead_advlock },	/* advlock */
+	{ &vop_blkatoff_desc, dead_blkatoff },	/* blkatoff */
+	{ &vop_valloc_desc, dead_valloc },	/* valloc */
+	{ &vop_vfree_desc, dead_vfree },	/* vfree */
+	{ &vop_truncate_desc, dead_truncate },	/* truncate */
+	{ &vop_update_desc, dead_update },	/* update */
+	{ &vop_bwrite_desc, dead_bwrite },	/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc dead_vnodeop_opv_desc =
+	{ &dead_vnodeop_p, dead_vnodeop_entries };
+
+/*
+ * Trivial lookup routine that always fails.
+ */
+/* ARGSUSED */
+int
+dead_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode * a_dvp;
+		struct vnode ** a_vpp;
+		struct componentname * a_cnp;
+	} */ *ap;
+{
+
+	*ap->a_vpp = NULL;
+	return (ENOTDIR);
+}
+
+/*
+ * Open always fails as if device did not exist.
+ */
+/* ARGSUSED */
+dead_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	return (ENXIO);
+}
+
+/*
+ * Vnode op for read
+ */
+/* ARGSUSED */
+dead_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+
+	if (chkvnlock(ap->a_vp))
+		panic("dead_read: lock");
+	/*
+	 * Return EOF for character devices, EIO for others
+	 */
+	if (ap->a_vp->v_type != VCHR)
+		return (EIO);
+	return (0);
+}
+
+/*
+ * Vnode op for write
+ */
+/* ARGSUSED */
+dead_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+
+	if (chkvnlock(ap->a_vp))
+		panic("dead_write: lock");
+	return (EIO);
+}
+
+/*
+ * Device ioctl operation.
+ */
+/* ARGSUSED */
+dead_ioctl(ap)
+	struct vop_ioctl_args /* {
+		struct vnode *a_vp;
+		int  a_command;
+		caddr_t  a_data;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	if (!chkvnlock(ap->a_vp))
+		return (EBADF);
+	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
+}
+
+/* ARGSUSED */
+dead_select(ap)
+	struct vop_select_args /* {
+		struct vnode *a_vp;
+		int  a_which;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	/*
+	 * Let the user find out that the descriptor is gone.
+	 */
+	return (1);
+}
+
+/*
+ * Just call the device strategy routine
+ */
+dead_strategy(ap)
+	struct vop_strategy_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+
+	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
+		ap->a_bp->b_flags |= B_ERROR;
+		biodone(ap->a_bp);
+		return (EIO);
+	}
+	return (VOP_STRATEGY(ap->a_bp));
+}
+
+/*
+ * Wait until the vnode has finished changing state.
+ */
+dead_lock(ap)
+	struct vop_lock_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	if (!chkvnlock(ap->a_vp))
+		return (0);
+	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
+}
+
+/*
+ * Wait until the vnode has finished changing state.
+ */
+dead_bmap(ap)
+	struct vop_bmap_args /* {
+		struct vnode *a_vp;
+		daddr_t  a_bn;
+		struct vnode **a_vpp;
+		daddr_t *a_bnp;
+		int *a_runp;
+	} */ *ap;
+{
+
+	if (!chkvnlock(ap->a_vp))
+		return (EIO);
+	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
+}
+
+/*
+ * Print out the contents of a dead vnode.
+ */
+/* ARGSUSED */
+dead_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_NON, dead vnode\n");
+}
+
+/*
+ * Empty vnode failed operation
+ */
+dead_ebadf()
+{
+
+	return (EBADF);
+}
+
+/*
+ * Empty vnode bad operation
+ */
+dead_badop()
+{
+
+	panic("dead_badop called");
+	/* NOTREACHED */
+}
+
+/*
+ * Empty vnode null operation
+ */
+dead_nullop()
+{
+
+	return (0);
+}
+
+/*
+ * We have to wait during times when the vnode is
+ * in a state of change.
+ */
+chkvnlock(vp)
+	register struct vnode *vp;
+{
+	int locked = 0;
+
+	while (vp->v_flag & VXLOCK) {
+		vp->v_flag |= VXWANT;
+		sleep((caddr_t)vp, PINOD);
+		locked = 1;
+	}
+	return (locked);
+}
diff --git a/sys/miscfs/fdesc/fdesc.h b/sys/miscfs/fdesc/fdesc.h
new file mode 100644
index 0000000..4c682e7
--- /dev/null
+++ b/sys/miscfs/fdesc/fdesc.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)fdesc.h	8.5 (Berkeley) 1/21/94
+ *
+ * $Id: fdesc.h,v 1.8 1993/04/06 15:28:33 jsp Exp $
+ */
+
+#ifdef KERNEL
+struct fdescmount {
+	struct vnode	*f_root;	/* Root node */
+};
+
+#define FD_ROOT		2
+#define FD_DEVFD	3
+#define FD_STDIN	4
+#define FD_STDOUT	5
+#define FD_STDERR	6
+#define FD_CTTY		7
+#define FD_DESC		8
+#define FD_MAX		12
+
+typedef enum {
+	Froot,
+	Fdevfd,
+	Fdesc,
+	Flink,
+	Fctty
+} fdntype;
+
+struct fdescnode {
+	struct fdescnode *fd_forw;	/* Hash chain */
+	struct fdescnode *fd_back;
+	struct vnode	*fd_vnode;	/* Back ptr to vnode */
+	fdntype		fd_type;	/* Type of this node */
+	unsigned	fd_fd;		/* Fd to be dup'ed */
+	char		*fd_link;	/* Link to fd/n */
+	int		fd_ix;		/* filesystem index */
+};
+
+#define VFSTOFDESC(mp)	((struct fdescmount *)((mp)->mnt_data))
+#define	VTOFDESC(vp) ((struct fdescnode *)(vp)->v_data)
+
+extern dev_t devctty;
+extern int fdesc_init __P((void));
+extern int fdesc_root __P((struct mount *, struct vnode **));
+extern int fdesc_allocvp __P((fdntype, int, struct mount *, struct vnode **));
+extern int (**fdesc_vnodeop_p)();
+extern struct vfsops fdesc_vfsops;
+#endif /* KERNEL */
diff --git a/sys/miscfs/fdesc/fdesc_vfsops.c b/sys/miscfs/fdesc/fdesc_vfsops.c
new file mode 100644
index 0000000..80c543d
--- /dev/null
+++ b/sys/miscfs/fdesc/fdesc_vfsops.c
@@ -0,0 +1,288 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)fdesc_vfsops.c	8.4 (Berkeley) 1/21/94
+ *
+ * $Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp $
+ */
+
+/*
+ * /dev/fd Filesystem
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+#include <sys/resourcevar.h>
+#include <sys/filedesc.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/fdesc/fdesc.h>
+
+/*
+ * Mount the per-process file descriptors (/dev/fd)
+ */
+int
+fdesc_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	int error = 0;
+	u_int size;
+	struct fdescmount *fmp;
+	struct vnode *rvp;
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE)
+		return (EOPNOTSUPP);
+
+	error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
+	if (error)
+		return (error);
+
+	MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
+				M_UFSMNT, M_WAITOK);	/* XXX */
+	rvp->v_type = VDIR;
+	rvp->v_flag |= VROOT;
+	fmp->f_root = rvp;
+	/* XXX -- don't mark as local to work around fts() problems */
+	/*mp->mnt_flag |= MNT_LOCAL;*/
+	mp->mnt_data = (qaddr_t) fmp;
+	getnewfsid(mp, MOUNT_FDESC);
+
+	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
+	bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
+	return (0);
+}
+
+int
+fdesc_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+	return (0);
+}
+
+int
+fdesc_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	int error;
+	int flags = 0;
+	extern int doforce;
+	struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
+
+	if (mntflags & MNT_FORCE) {
+		/* fdesc can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	/*
+	 * Clear out buffer cache.  I don't think we
+	 * ever get anything cached at this level at the
+	 * moment, but who knows...
+	 */
+	if (rootvp->v_usecount > 1)
+		return (EBUSY);
+	if (error = vflush(mp, rootvp, flags))
+		return (error);
+
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vrele(rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(rootvp);
+	/*
+	 * Finally, throw away the fdescmount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+
+	return (0);
+}
+
+int
+fdesc_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct vnode *vp;
+
+	/*
+	 * Return locked reference to root.
+	 */
+	vp = VFSTOFDESC(mp)->f_root;
+	VREF(vp);
+	VOP_LOCK(vp);
+	*vpp = vp;
+	return (0);
+}
+
+int
+fdesc_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+fdesc_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+	struct filedesc *fdp;
+	int lim;
+	int i;
+	int last;
+	int freefd;
+
+	/*
+	 * Compute number of free file descriptors.
+	 * [ Strange results will ensue if the open file
+	 * limit is ever reduced below the current number
+	 * of open files... ]
+	 */
+	lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
+	fdp = p->p_fd;
+	last = min(fdp->fd_nfiles, lim);
+	freefd = 0;
+	for (i = fdp->fd_freefile; i < last; i++)
+		if (fdp->fd_ofiles[i] == NULL)
+			freefd++;
+
+	/*
+	 * Adjust for the fact that the fdesc array may not
+	 * have been fully allocated yet.
+	 */
+	if (fdp->fd_nfiles < lim)
+		freefd += (lim - fdp->fd_nfiles);
+
+	sbp->f_type = MOUNT_FDESC;
+	sbp->f_flags = 0;
+	sbp->f_bsize = DEV_BSIZE;
+	sbp->f_iosize = DEV_BSIZE;
+	sbp->f_blocks = 2;		/* 1K to keep df happy */
+	sbp->f_bfree = 0;
+	sbp->f_bavail = 0;
+	sbp->f_files = lim + 1;		/* Allow for "." */
+	sbp->f_ffree = freefd;		/* See comments above */
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+int
+fdesc_sync(mp, waitfor)
+	struct mount *mp;
+	int waitfor;
+{
+
+	return (0);
+}
+
+/*
+ * Fdesc flat namespace lookup.
+ * Currently unsupported.
+ */
+int
+fdesc_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+fdesc_fhtovp(mp, fhp, setgen, vpp)
+	struct mount *mp;
+	struct fid *fhp;
+	int setgen;
+	struct vnode **vpp;
+{
+	return (EOPNOTSUPP);
+}
+
+int
+fdesc_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+struct vfsops fdesc_vfsops = {
+	fdesc_mount,
+	fdesc_start,
+	fdesc_unmount,
+	fdesc_root,
+	fdesc_quotactl,
+	fdesc_statfs,
+	fdesc_sync,
+	fdesc_vget,
+	fdesc_fhtovp,
+	fdesc_vptofh,
+	fdesc_init,
+};
diff --git a/sys/miscfs/fdesc/fdesc_vnops.c b/sys/miscfs/fdesc/fdesc_vnops.c
new file mode 100644
index 0000000..00d8675
--- /dev/null
+++ b/sys/miscfs/fdesc/fdesc_vnops.c
@@ -0,0 +1,974 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)fdesc_vnops.c	8.9 (Berkeley) 1/21/94
+ *
+ * $Id: fdesc_vnops.c,v 1.12 1993/04/06 16:17:17 jsp Exp $
+ */
+
+/*
+ * /dev/fd Filesystem
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/proc.h>
+#include <sys/kernel.h>	/* boottime */
+#include <sys/resourcevar.h>
+#include <sys/filedesc.h>
+#include <sys/vnode.h>
+#include <sys/malloc.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/buf.h>
+#include <sys/dirent.h>
+#include <miscfs/fdesc/fdesc.h>
+
+#define cttyvp(p) ((p)->p_flag & P_CONTROLT ? (p)->p_session->s_ttyvp : NULL)
+
+#define FDL_WANT	0x01
+#define FDL_LOCKED	0x02
+static int fdcache_lock;
+
+dev_t devctty;
+
+#if (FD_STDIN != FD_STDOUT-1) || (FD_STDOUT != FD_STDERR-1)
+FD_STDIN, FD_STDOUT, FD_STDERR must be a sequence n, n+1, n+2
+#endif
+
+#define	NFDCACHE 3
+#define	FD_NHASH(ix) ((ix) & NFDCACHE)
+
+/*
+ * Cache head
+ */
+struct fdcache {
+	struct fdescnode	*fc_forw;
+	struct fdescnode	*fc_back;
+};
+
+static struct fdcache fdcache[NFDCACHE];
+
+/*
+ * Initialise cache headers
+ */
+fdesc_init()
+{
+	struct fdcache *fc;
+
+	devctty = makedev(nchrdev, 0);
+
+	for (fc = fdcache; fc < fdcache + NFDCACHE; fc++)
+		fc->fc_forw = fc->fc_back = (struct fdescnode *) fc;
+}
+
+/*
+ * Compute hash list for given target vnode
+ */
+static struct fdcache *
+fdesc_hash(ix)
+	int ix;
+{
+
+	return (&fdcache[FD_NHASH(ix)]);
+}
+
+int
+fdesc_allocvp(ftype, ix, mp, vpp)
+	fdntype ftype;
+	int ix;
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct fdcache *fc;
+	struct fdescnode *fd;
+	int error = 0;
+
+loop:
+	fc = fdesc_hash(ix);
+	for (fd = fc->fc_forw; fd != (struct fdescnode *) fc; fd = fd->fd_forw) {
+		if (fd->fd_ix == ix && fd->fd_vnode->v_mount == mp) {
+			if (vget(fd->fd_vnode, 0))
+				goto loop;
+			*vpp = fd->fd_vnode;
+			return (error);
+		}
+	}
+
+	/*
+	 * otherwise lock the array while we call getnewvnode
+	 * since that can block.
+	 */ 
+	if (fdcache_lock & FDL_LOCKED) {
+		fdcache_lock |= FDL_WANT;
+		sleep((caddr_t) &fdcache_lock, PINOD);
+		goto loop;
+	}
+	fdcache_lock |= FDL_LOCKED;
+
+	error = getnewvnode(VT_FDESC, mp, fdesc_vnodeop_p, vpp);
+	if (error)
+		goto out;
+	MALLOC(fd, void *, sizeof(struct fdescnode), M_TEMP, M_WAITOK);
+	(*vpp)->v_data = fd;
+	fd->fd_vnode = *vpp;
+	fd->fd_type = ftype;
+	fd->fd_fd = -1;
+	fd->fd_link = 0;
+	fd->fd_ix = ix;
+	fc = fdesc_hash(ix);
+	insque(fd, fc);
+
+out:;
+	fdcache_lock &= ~FDL_LOCKED;
+
+	if (fdcache_lock & FDL_WANT) {
+		fdcache_lock &= ~FDL_WANT;
+		wakeup((caddr_t) &fdcache_lock);
+	}
+
+	return (error);
+}
+
+/*
+ * vp is the current namei directory
+ * ndp is the name to locate in that directory...
+ */
+int
+fdesc_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode * a_dvp;
+		struct vnode ** a_vpp;
+		struct componentname * a_cnp;
+	} */ *ap;
+{
+	struct vnode **vpp = ap->a_vpp;
+	struct vnode *dvp = ap->a_dvp;
+	char *pname;
+	struct proc *p;
+	int nfiles;
+	unsigned fd;
+	int error;
+	struct vnode *fvp;
+	char *ln;
+
+	pname = ap->a_cnp->cn_nameptr;
+	if (ap->a_cnp->cn_namelen == 1 && *pname == '.') {
+		*vpp = dvp;
+		VREF(dvp);	
+		VOP_LOCK(dvp);
+		return (0);
+	}
+
+	p = ap->a_cnp->cn_proc;
+	nfiles = p->p_fd->fd_nfiles;
+
+	switch (VTOFDESC(dvp)->fd_type) {
+	default:
+	case Flink:
+	case Fdesc:
+	case Fctty:
+		error = ENOTDIR;
+		goto bad;
+
+	case Froot:
+		if (ap->a_cnp->cn_namelen == 2 && bcmp(pname, "fd", 2) == 0) {
+			error = fdesc_allocvp(Fdevfd, FD_DEVFD, dvp->v_mount, &fvp);
+			if (error)
+				goto bad;
+			*vpp = fvp;
+			fvp->v_type = VDIR;
+			VOP_LOCK(fvp);
+			return (0);
+		}
+
+		if (ap->a_cnp->cn_namelen == 3 && bcmp(pname, "tty", 3) == 0) {
+			struct vnode *ttyvp = cttyvp(p);
+			if (ttyvp == NULL) {
+				error = ENXIO;
+				goto bad;
+			}
+			error = fdesc_allocvp(Fctty, FD_CTTY, dvp->v_mount, &fvp);
+			if (error)
+				goto bad;
+			*vpp = fvp;
+			fvp->v_type = VFIFO;
+			VOP_LOCK(fvp);
+			return (0);
+		}
+
+		ln = 0;
+		switch (ap->a_cnp->cn_namelen) {
+		case 5:
+			if (bcmp(pname, "stdin", 5) == 0) {
+				ln = "fd/0";
+				fd = FD_STDIN;
+			}
+			break;
+		case 6:
+			if (bcmp(pname, "stdout", 6) == 0) {
+				ln = "fd/1";
+				fd = FD_STDOUT;
+			} else
+			if (bcmp(pname, "stderr", 6) == 0) {
+				ln = "fd/2";
+				fd = FD_STDERR;
+			}
+			break;
+		}
+
+		if (ln) {
+			error = fdesc_allocvp(Flink, fd, dvp->v_mount, &fvp);
+			if (error)
+				goto bad;
+			VTOFDESC(fvp)->fd_link = ln;
+			*vpp = fvp;
+			fvp->v_type = VLNK;
+			VOP_LOCK(fvp);
+			return (0);
+		} else {
+			error = ENOENT;
+			goto bad;
+		}
+
+		/* FALL THROUGH */
+
+	case Fdevfd:
+		if (ap->a_cnp->cn_namelen == 2 && bcmp(pname, "..", 2) == 0) {
+			error = fdesc_root(dvp->v_mount, vpp);
+			return (error);
+		}
+
+		fd = 0;
+		while (*pname >= '0' && *pname <= '9') {
+			fd = 10 * fd + *pname++ - '0';
+			if (fd >= nfiles)
+				break;
+		}
+
+		if (*pname != '\0') {
+			error = ENOENT;
+			goto bad;
+		}
+
+		if (fd >= nfiles || p->p_fd->fd_ofiles[fd] == NULL) {
+			error = EBADF;
+			goto bad;
+		}
+
+		error = fdesc_allocvp(Fdesc, FD_DESC+fd, dvp->v_mount, &fvp);
+		if (error)
+			goto bad;
+		VTOFDESC(fvp)->fd_fd = fd;
+		*vpp = fvp;
+		return (0);
+	}
+
+bad:;
+	*vpp = NULL;
+	return (error);
+}
+
+int
+fdesc_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	int error = 0;
+
+	switch (VTOFDESC(vp)->fd_type) {
+	case Fdesc:
+		/*
+		 * XXX Kludge: set p->p_dupfd to contain the value of the
+		 * the file descriptor being sought for duplication. The error 
+		 * return ensures that the vnode for this device will be
+		 * released by vn_open. Open will detect this special error and
+		 * take the actions in dupfdopen.  Other callers of vn_open or
+		 * VOP_OPEN will simply report the error.
+		 */
+		ap->a_p->p_dupfd = VTOFDESC(vp)->fd_fd;	/* XXX */
+		error = ENODEV;
+		break;
+
+	case Fctty:
+		error = cttyopen(devctty, ap->a_mode, 0, ap->a_p);
+		break;
+	}
+
+	return (error);
+}
+
+static int
+fdesc_attr(fd, vap, cred, p)
+	int fd;
+	struct vattr *vap;
+	struct ucred *cred;
+	struct proc *p;
+{
+	struct filedesc *fdp = p->p_fd;
+	struct file *fp;
+	struct stat stb;
+	int error;
+
+	if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL)
+		return (EBADF);
+
+	switch (fp->f_type) {
+	case DTYPE_VNODE:
+		error = VOP_GETATTR((struct vnode *) fp->f_data, vap, cred, p);
+		if (error == 0 && vap->va_type == VDIR) {
+			/*
+			 * don't allow directories to show up because
+			 * that causes loops in the namespace.
+			 */
+			vap->va_type = VFIFO;
+		}
+		break;
+
+	case DTYPE_SOCKET:
+		error = soo_stat((struct socket *)fp->f_data, &stb);
+		if (error == 0) {
+			vattr_null(vap);
+			vap->va_type = VSOCK;
+			vap->va_mode = stb.st_mode;
+			vap->va_nlink = stb.st_nlink;
+			vap->va_uid = stb.st_uid;
+			vap->va_gid = stb.st_gid;
+			vap->va_fsid = stb.st_dev;
+			vap->va_fileid = stb.st_ino;
+			vap->va_size = stb.st_size;
+			vap->va_blocksize = stb.st_blksize;
+			vap->va_atime = stb.st_atimespec;
+			vap->va_mtime = stb.st_mtimespec;
+			vap->va_ctime = stb.st_ctimespec;
+			vap->va_gen = stb.st_gen;
+			vap->va_flags = stb.st_flags;
+			vap->va_rdev = stb.st_rdev;
+			vap->va_bytes = stb.st_blocks * stb.st_blksize;
+		}
+		break;
+
+	default:
+		panic("fdesc attr");
+		break;
+	}
+
+	return (error);
+}
+
+int
+fdesc_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct vattr *vap = ap->a_vap;
+	unsigned fd;
+	int error = 0;
+
+	switch (VTOFDESC(vp)->fd_type) {
+	case Froot:
+	case Fdevfd:
+	case Flink:
+	case Fctty:
+		bzero((caddr_t) vap, sizeof(*vap));
+		vattr_null(vap);
+		vap->va_fileid = VTOFDESC(vp)->fd_ix;
+
+		switch (VTOFDESC(vp)->fd_type) {
+		case Flink:
+			vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
+			vap->va_type = VLNK;
+			vap->va_nlink = 1;
+			vap->va_size = strlen(VTOFDESC(vp)->fd_link);
+			break;
+
+		case Fctty:
+			vap->va_mode = S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH;
+			vap->va_type = VFIFO;
+			vap->va_nlink = 1;
+			vap->va_size = 0;
+			break;
+
+		default:
+			vap->va_mode = S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH;
+			vap->va_type = VDIR;
+			vap->va_nlink = 2;
+			vap->va_size = DEV_BSIZE;
+			break;
+		}
+		vap->va_uid = 0;
+		vap->va_gid = 0;
+		vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
+		vap->va_blocksize = DEV_BSIZE;
+		vap->va_atime.ts_sec = boottime.tv_sec;
+		vap->va_atime.ts_nsec = 0;
+		vap->va_mtime = vap->va_atime;
+		vap->va_ctime = vap->va_mtime;
+		vap->va_gen = 0;
+		vap->va_flags = 0;
+		vap->va_rdev = 0;
+		vap->va_bytes = 0;
+		break;
+
+	case Fdesc:
+		fd = VTOFDESC(vp)->fd_fd;
+		error = fdesc_attr(fd, vap, ap->a_cred, ap->a_p);
+		break;
+
+	default:
+		panic("fdesc_getattr");
+		break;	
+	}
+
+	if (error == 0)
+		vp->v_type = vap->va_type;
+
+	return (error);
+}
+
+int
+fdesc_setattr(ap)
+	struct vop_setattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct filedesc *fdp = ap->a_p->p_fd;
+	struct file *fp;
+	unsigned fd;
+	int error;
+
+	/*
+	 * Can't mess with the root vnode
+	 */
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fdesc:
+		break;
+
+	case Fctty:
+		return (0);
+
+	default:
+		return (EACCES);
+	}
+
+	fd = VTOFDESC(ap->a_vp)->fd_fd;
+	if (fd >= fdp->fd_nfiles || (fp = fdp->fd_ofiles[fd]) == NULL) {
+		return (EBADF);
+	}
+
+	/*
+	 * Can setattr the underlying vnode, but not sockets!
+	 */
+	switch (fp->f_type) {
+	case DTYPE_VNODE:
+		error = VOP_SETATTR((struct vnode *) fp->f_data, ap->a_vap, ap->a_cred, ap->a_p);
+		break;
+
+	case DTYPE_SOCKET:
+		error = 0;
+		break;
+
+	default:
+		panic("fdesc setattr");
+		break;
+	}
+
+	return (error);
+}
+
+#define UIO_MX 16
+
+static struct dirtmp {
+	u_long d_fileno;
+	u_short d_reclen;
+	u_short d_namlen;
+	char d_name[8];
+} rootent[] = {
+	{ FD_DEVFD, UIO_MX, 2, "fd" },
+	{ FD_STDIN, UIO_MX, 5, "stdin" },
+	{ FD_STDOUT, UIO_MX, 6, "stdout" },
+	{ FD_STDERR, UIO_MX, 6, "stderr" },
+	{ FD_CTTY, UIO_MX, 3, "tty" },
+	{ 0 }
+};
+
+int
+fdesc_readdir(ap)
+	struct vop_readdir_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct uio *uio = ap->a_uio;
+	struct filedesc *fdp;
+	int i;
+	int error;
+
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fctty:
+		return (0);
+
+	case Fdesc:
+		return (ENOTDIR);
+
+	default:
+		break;
+	}
+
+	fdp = uio->uio_procp->p_fd;
+
+	if (VTOFDESC(ap->a_vp)->fd_type == Froot) {
+		struct dirent d;
+		struct dirent *dp = &d;
+		struct dirtmp *dt;
+
+		i = uio->uio_offset / UIO_MX;
+		error = 0;
+
+		while (uio->uio_resid > 0) {
+			dt = &rootent[i];
+			if (dt->d_fileno == 0) {
+				/**eofflagp = 1;*/
+				break;
+			}
+			i++;
+			
+			switch (dt->d_fileno) {
+			case FD_CTTY:
+				if (cttyvp(uio->uio_procp) == NULL)
+					continue;
+				break;
+
+			case FD_STDIN:
+			case FD_STDOUT:
+			case FD_STDERR:
+				if ((dt->d_fileno-FD_STDIN) >= fdp->fd_nfiles)
+					continue;
+				if (fdp->fd_ofiles[dt->d_fileno-FD_STDIN] == NULL)
+					continue;
+				break;
+			}
+			bzero((caddr_t) dp, UIO_MX);
+			dp->d_fileno = dt->d_fileno;
+			dp->d_namlen = dt->d_namlen;
+			dp->d_type = DT_UNKNOWN;
+			dp->d_reclen = dt->d_reclen;
+			bcopy(dt->d_name, dp->d_name, dp->d_namlen+1);
+			error = uiomove((caddr_t) dp, UIO_MX, uio);
+			if (error)
+				break;
+		}
+		uio->uio_offset = i * UIO_MX;
+		return (error);
+	}
+
+	i = uio->uio_offset / UIO_MX;
+	error = 0;
+	while (uio->uio_resid > 0) {
+		if (i >= fdp->fd_nfiles)
+			break;
+
+		if (fdp->fd_ofiles[i] != NULL) {
+			struct dirent d;
+			struct dirent *dp = &d;
+
+			bzero((caddr_t) dp, UIO_MX);
+
+			dp->d_namlen = sprintf(dp->d_name, "%d", i);
+			dp->d_reclen = UIO_MX;
+			dp->d_type = DT_UNKNOWN;
+			dp->d_fileno = i + FD_STDIN;
+			/*
+			 * And ship to userland
+			 */
+			error = uiomove((caddr_t) dp, UIO_MX, uio);
+			if (error)
+				break;
+		}
+		i++;
+	}
+
+	uio->uio_offset = i * UIO_MX;
+	return (error);
+}
+
+int
+fdesc_readlink(ap)
+	struct vop_readlink_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	int error;
+
+	if (vp->v_type != VLNK)
+		return (EPERM);
+
+	if (VTOFDESC(vp)->fd_type == Flink) {
+		char *ln = VTOFDESC(vp)->fd_link;
+		error = uiomove(ln, strlen(ln), ap->a_uio);
+	} else {
+		error = EOPNOTSUPP;
+	}
+
+	return (error);
+}
+
+int
+fdesc_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error = EOPNOTSUPP;
+
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fctty:
+		error = cttyread(devctty, ap->a_uio, ap->a_ioflag);
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	
+	return (error);
+}
+
+int
+fdesc_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error = EOPNOTSUPP;
+
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fctty:
+		error = cttywrite(devctty, ap->a_uio, ap->a_ioflag);
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	
+	return (error);
+}
+
+int
+fdesc_ioctl(ap)
+	struct vop_ioctl_args /* {
+		struct vnode *a_vp;
+		int  a_command;
+		caddr_t  a_data;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	int error = EOPNOTSUPP;
+
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fctty:
+		error = cttyioctl(devctty, ap->a_command, ap->a_data,
+					ap->a_fflag, ap->a_p);
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	
+	return (error);
+}
+
+int
+fdesc_select(ap)
+	struct vop_select_args /* {
+		struct vnode *a_vp;
+		int  a_which;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	int error = EOPNOTSUPP;
+
+	switch (VTOFDESC(ap->a_vp)->fd_type) {
+	case Fctty:
+		error = cttyselect(devctty, ap->a_fflags, ap->a_p);
+		break;
+
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	
+	return (error);
+}
+
+int
+fdesc_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	/*
+	 * Clear out the v_type field to avoid
+	 * nasty things happening in vgone().
+	 */
+	vp->v_type = VNON;
+	return (0);
+}
+
+int
+fdesc_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	remque(VTOFDESC(vp));
+	FREE(vp->v_data, M_TEMP);
+	vp->v_data = 0;
+
+	return (0);
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+fdesc_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_MAX_CANON:
+		*ap->a_retval = MAX_CANON;
+		return (0);
+	case _PC_MAX_INPUT:
+		*ap->a_retval = MAX_INPUT;
+		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_VDISABLE:
+		*ap->a_retval = _POSIX_VDISABLE;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Print out the contents of a /dev/fd vnode.
+ */
+/* ARGSUSED */
+int
+fdesc_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_NON, fdesc vnode\n");
+	return (0);
+}
+
+/*void*/
+int
+fdesc_vfree(ap)
+	struct vop_vfree_args /* {
+		struct vnode *a_pvp;
+		ino_t a_ino;
+		int a_mode;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/*
+ * /dev/fd vnode unsupported operation
+ */
+int
+fdesc_enotsupp()
+{
+
+	return (EOPNOTSUPP);
+}
+
+/*
+ * /dev/fd "should never get here" operation
+ */
+int
+fdesc_badop()
+{
+
+	panic("fdesc: bad op");
+	/* NOTREACHED */
+}
+
+/*
+ * /dev/fd vnode null operation
+ */
+int
+fdesc_nullop()
+{
+
+	return (0);
+}
+
+#define fdesc_create ((int (*) __P((struct  vop_create_args *)))fdesc_enotsupp)
+#define fdesc_mknod ((int (*) __P((struct  vop_mknod_args *)))fdesc_enotsupp)
+#define fdesc_close ((int (*) __P((struct  vop_close_args *)))nullop)
+#define fdesc_access ((int (*) __P((struct  vop_access_args *)))nullop)
+#define fdesc_mmap ((int (*) __P((struct  vop_mmap_args *)))fdesc_enotsupp)
+#define fdesc_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
+#define fdesc_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
+#define fdesc_remove ((int (*) __P((struct  vop_remove_args *)))fdesc_enotsupp)
+#define fdesc_link ((int (*) __P((struct  vop_link_args *)))fdesc_enotsupp)
+#define fdesc_rename ((int (*) __P((struct  vop_rename_args *)))fdesc_enotsupp)
+#define fdesc_mkdir ((int (*) __P((struct  vop_mkdir_args *)))fdesc_enotsupp)
+#define fdesc_rmdir ((int (*) __P((struct  vop_rmdir_args *)))fdesc_enotsupp)
+#define fdesc_symlink ((int (*) __P((struct vop_symlink_args *)))fdesc_enotsupp)
+#define fdesc_abortop ((int (*) __P((struct  vop_abortop_args *)))nullop)
+#define fdesc_lock ((int (*) __P((struct  vop_lock_args *)))nullop)
+#define fdesc_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
+#define fdesc_bmap ((int (*) __P((struct  vop_bmap_args *)))fdesc_badop)
+#define fdesc_strategy ((int (*) __P((struct  vop_strategy_args *)))fdesc_badop)
+#define fdesc_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+#define fdesc_advlock ((int (*) __P((struct vop_advlock_args *)))fdesc_enotsupp)
+#define fdesc_blkatoff \
+	((int (*) __P((struct  vop_blkatoff_args *)))fdesc_enotsupp)
+#define fdesc_vget ((int (*) __P((struct  vop_vget_args *)))fdesc_enotsupp)
+#define fdesc_valloc ((int(*) __P(( \
+		struct vnode *pvp, \
+		int mode, \
+		struct ucred *cred, \
+		struct vnode **vpp))) fdesc_enotsupp)
+#define fdesc_truncate \
+	((int (*) __P((struct  vop_truncate_args *)))fdesc_enotsupp)
+#define fdesc_update ((int (*) __P((struct  vop_update_args *)))fdesc_enotsupp)
+#define fdesc_bwrite ((int (*) __P((struct  vop_bwrite_args *)))fdesc_enotsupp)
+
+int (**fdesc_vnodeop_p)();
+struct vnodeopv_entry_desc fdesc_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, fdesc_lookup },	/* lookup */
+	{ &vop_create_desc, fdesc_create },	/* create */
+	{ &vop_mknod_desc, fdesc_mknod },	/* mknod */
+	{ &vop_open_desc, fdesc_open },		/* open */
+	{ &vop_close_desc, fdesc_close },	/* close */
+	{ &vop_access_desc, fdesc_access },	/* access */
+	{ &vop_getattr_desc, fdesc_getattr },	/* getattr */
+	{ &vop_setattr_desc, fdesc_setattr },	/* setattr */
+	{ &vop_read_desc, fdesc_read },		/* read */
+	{ &vop_write_desc, fdesc_write },	/* write */
+	{ &vop_ioctl_desc, fdesc_ioctl },	/* ioctl */
+	{ &vop_select_desc, fdesc_select },	/* select */
+	{ &vop_mmap_desc, fdesc_mmap },		/* mmap */
+	{ &vop_fsync_desc, fdesc_fsync },	/* fsync */
+	{ &vop_seek_desc, fdesc_seek },		/* seek */
+	{ &vop_remove_desc, fdesc_remove },	/* remove */
+	{ &vop_link_desc, fdesc_link },		/* link */
+	{ &vop_rename_desc, fdesc_rename },	/* rename */
+	{ &vop_mkdir_desc, fdesc_mkdir },	/* mkdir */
+	{ &vop_rmdir_desc, fdesc_rmdir },	/* rmdir */
+	{ &vop_symlink_desc, fdesc_symlink },	/* symlink */
+	{ &vop_readdir_desc, fdesc_readdir },	/* readdir */
+	{ &vop_readlink_desc, fdesc_readlink },	/* readlink */
+	{ &vop_abortop_desc, fdesc_abortop },	/* abortop */
+	{ &vop_inactive_desc, fdesc_inactive },	/* inactive */
+	{ &vop_reclaim_desc, fdesc_reclaim },	/* reclaim */
+	{ &vop_lock_desc, fdesc_lock },		/* lock */
+	{ &vop_unlock_desc, fdesc_unlock },	/* unlock */
+	{ &vop_bmap_desc, fdesc_bmap },		/* bmap */
+	{ &vop_strategy_desc, fdesc_strategy },	/* strategy */
+	{ &vop_print_desc, fdesc_print },	/* print */
+	{ &vop_islocked_desc, fdesc_islocked },	/* islocked */
+	{ &vop_pathconf_desc, fdesc_pathconf },	/* pathconf */
+	{ &vop_advlock_desc, fdesc_advlock },	/* advlock */
+	{ &vop_blkatoff_desc, fdesc_blkatoff },	/* blkatoff */
+	{ &vop_valloc_desc, fdesc_valloc },	/* valloc */
+	{ &vop_vfree_desc, fdesc_vfree },	/* vfree */
+	{ &vop_truncate_desc, fdesc_truncate },	/* truncate */
+	{ &vop_update_desc, fdesc_update },	/* update */
+	{ &vop_bwrite_desc, fdesc_bwrite },	/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc fdesc_vnodeop_opv_desc =
+	{ &fdesc_vnodeop_p, fdesc_vnodeop_entries };
diff --git a/sys/miscfs/fifofs/fifo.h b/sys/miscfs/fifofs/fifo.h
new file mode 100644
index 0000000..e89186d
--- /dev/null
+++ b/sys/miscfs/fifofs/fifo.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 1991, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ *
+ *	@(#)fifo.h	8.2 (Berkeley) 2/2/94
+ */
+
+#ifdef FIFO
+/*
+ * Prototypes for fifo operations on vnodes.
+ */
+int	fifo_badop(),
+	fifo_ebadf();
+
+int	fifo_lookup __P((struct vop_lookup_args *));
+#define fifo_create ((int (*) __P((struct  vop_create_args *)))fifo_badop)
+#define fifo_mknod ((int (*) __P((struct  vop_mknod_args *)))fifo_badop)
+int	fifo_open __P((struct vop_open_args *));
+int	fifo_close __P((struct vop_close_args *));
+#define fifo_access ((int (*) __P((struct  vop_access_args *)))fifo_ebadf)
+#define fifo_getattr ((int (*) __P((struct  vop_getattr_args *)))fifo_ebadf)
+#define fifo_setattr ((int (*) __P((struct  vop_setattr_args *)))fifo_ebadf)
+int	fifo_read __P((struct vop_read_args *));
+int	fifo_write __P((struct vop_write_args *));
+int	fifo_ioctl __P((struct vop_ioctl_args *));
+int	fifo_select __P((struct vop_select_args *));
+#define fifo_mmap ((int (*) __P((struct  vop_mmap_args *)))fifo_badop)
+#define fifo_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
+#define fifo_seek ((int (*) __P((struct  vop_seek_args *)))fifo_badop)
+#define fifo_remove ((int (*) __P((struct  vop_remove_args *)))fifo_badop)
+#define fifo_link ((int (*) __P((struct  vop_link_args *)))fifo_badop)
+#define fifo_rename ((int (*) __P((struct  vop_rename_args *)))fifo_badop)
+#define fifo_mkdir ((int (*) __P((struct  vop_mkdir_args *)))fifo_badop)
+#define fifo_rmdir ((int (*) __P((struct  vop_rmdir_args *)))fifo_badop)
+#define fifo_symlink ((int (*) __P((struct  vop_symlink_args *)))fifo_badop)
+#define fifo_readdir ((int (*) __P((struct  vop_readdir_args *)))fifo_badop)
+#define fifo_readlink ((int (*) __P((struct  vop_readlink_args *)))fifo_badop)
+#define fifo_abortop ((int (*) __P((struct  vop_abortop_args *)))fifo_badop)
+#define fifo_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
+#define fifo_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
+int	fifo_lock __P((struct vop_lock_args *));
+int	fifo_unlock __P((struct vop_unlock_args *));
+int	fifo_bmap __P((struct vop_bmap_args *));
+#define fifo_strategy ((int (*) __P((struct  vop_strategy_args *)))fifo_badop)
+int	fifo_print __P((struct vop_print_args *));
+#define fifo_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+int	fifo_pathconf __P((struct vop_pathconf_args *));
+int	fifo_advlock __P((struct vop_advlock_args *));
+#define fifo_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))fifo_badop)
+#define fifo_valloc ((int (*) __P((struct  vop_valloc_args *)))fifo_badop)
+#define fifo_reallocblks \
+	((int (*) __P((struct  vop_reallocblks_args *)))fifo_badop)
+#define fifo_vfree ((int (*) __P((struct  vop_vfree_args *)))fifo_badop)
+#define fifo_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
+#define fifo_update ((int (*) __P((struct  vop_update_args *)))nullop)
+#define fifo_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
+#endif /* FIFO */
diff --git a/sys/miscfs/fifofs/fifo_vnops.c b/sys/miscfs/fifofs/fifo_vnops.c
new file mode 100644
index 0000000..bad33a4
--- /dev/null
+++ b/sys/miscfs/fifofs/fifo_vnops.c
@@ -0,0 +1,494 @@
+/*
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ *
+ *	@(#)fifo_vnops.c	8.2 (Berkeley) 1/4/94
+ */
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/time.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/stat.h>
+#include <sys/systm.h>
+#include <sys/ioctl.h>
+#include <sys/file.h>
+#include <sys/errno.h>
+#include <sys/malloc.h>
+#include <miscfs/fifofs/fifo.h>
+
+/*
+ * This structure is associated with the FIFO vnode and stores
+ * the state associated with the FIFO.
+ */
+struct fifoinfo {
+	struct socket	*fi_readsock;
+	struct socket	*fi_writesock;
+	long		fi_readers;
+	long		fi_writers;
+};
+
+int (**fifo_vnodeop_p)();
+struct vnodeopv_entry_desc fifo_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, fifo_lookup },		/* lookup */
+	{ &vop_create_desc, fifo_create },		/* create */
+	{ &vop_mknod_desc, fifo_mknod },		/* mknod */
+	{ &vop_open_desc, fifo_open },			/* open */
+	{ &vop_close_desc, fifo_close },		/* close */
+	{ &vop_access_desc, fifo_access },		/* access */
+	{ &vop_getattr_desc, fifo_getattr },		/* getattr */
+	{ &vop_setattr_desc, fifo_setattr },		/* setattr */
+	{ &vop_read_desc, fifo_read },			/* read */
+	{ &vop_write_desc, fifo_write },		/* write */
+	{ &vop_ioctl_desc, fifo_ioctl },		/* ioctl */
+	{ &vop_select_desc, fifo_select },		/* select */
+	{ &vop_mmap_desc, fifo_mmap },			/* mmap */
+	{ &vop_fsync_desc, fifo_fsync },		/* fsync */
+	{ &vop_seek_desc, fifo_seek },			/* seek */
+	{ &vop_remove_desc, fifo_remove },		/* remove */
+	{ &vop_link_desc, fifo_link },			/* link */
+	{ &vop_rename_desc, fifo_rename },		/* rename */
+	{ &vop_mkdir_desc, fifo_mkdir },		/* mkdir */
+	{ &vop_rmdir_desc, fifo_rmdir },		/* rmdir */
+	{ &vop_symlink_desc, fifo_symlink },		/* symlink */
+	{ &vop_readdir_desc, fifo_readdir },		/* readdir */
+	{ &vop_readlink_desc, fifo_readlink },		/* readlink */
+	{ &vop_abortop_desc, fifo_abortop },		/* abortop */
+	{ &vop_inactive_desc, fifo_inactive },		/* inactive */
+	{ &vop_reclaim_desc, fifo_reclaim },		/* reclaim */
+	{ &vop_lock_desc, fifo_lock },			/* lock */
+	{ &vop_unlock_desc, fifo_unlock },		/* unlock */
+	{ &vop_bmap_desc, fifo_bmap },			/* bmap */
+	{ &vop_strategy_desc, fifo_strategy },		/* strategy */
+	{ &vop_print_desc, fifo_print },		/* print */
+	{ &vop_islocked_desc, fifo_islocked },		/* islocked */
+	{ &vop_pathconf_desc, fifo_pathconf },		/* pathconf */
+	{ &vop_advlock_desc, fifo_advlock },		/* advlock */
+	{ &vop_blkatoff_desc, fifo_blkatoff },		/* blkatoff */
+	{ &vop_valloc_desc, fifo_valloc },		/* valloc */
+	{ &vop_vfree_desc, fifo_vfree },		/* vfree */
+	{ &vop_truncate_desc, fifo_truncate },		/* truncate */
+	{ &vop_update_desc, fifo_update },		/* update */
+	{ &vop_bwrite_desc, fifo_bwrite },		/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc fifo_vnodeop_opv_desc =
+	{ &fifo_vnodeop_p, fifo_vnodeop_entries };
+
+/*
+ * Trivial lookup routine that always fails.
+ */
+/* ARGSUSED */
+fifo_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode * a_dvp;
+		struct vnode ** a_vpp;
+		struct componentname * a_cnp;
+	} */ *ap;
+{
+	
+	*ap->a_vpp = NULL;
+	return (ENOTDIR);
+}
+
+/*
+ * Open called to set up a new instance of a fifo or
+ * to find an active instance of a fifo.
+ */
+/* ARGSUSED */
+fifo_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	register struct fifoinfo *fip;
+	struct socket *rso, *wso;
+	int error;
+	static char openstr[] = "fifo";
+
+	if ((ap->a_mode & (FREAD|FWRITE)) == (FREAD|FWRITE))
+		return (EINVAL);
+	if ((fip = vp->v_fifoinfo) == NULL) {
+		MALLOC(fip, struct fifoinfo *, sizeof(*fip), M_VNODE, M_WAITOK);
+		vp->v_fifoinfo = fip;
+		if (error = socreate(AF_UNIX, &rso, SOCK_STREAM, 0)) {
+			free(fip, M_VNODE);
+			vp->v_fifoinfo = NULL;
+			return (error);
+		}
+		fip->fi_readsock = rso;
+		if (error = socreate(AF_UNIX, &wso, SOCK_STREAM, 0)) {
+			(void)soclose(rso);
+			free(fip, M_VNODE);
+			vp->v_fifoinfo = NULL;
+			return (error);
+		}
+		fip->fi_writesock = wso;
+		if (error = unp_connect2(wso, rso)) {
+			(void)soclose(wso);
+			(void)soclose(rso);
+			free(fip, M_VNODE);
+			vp->v_fifoinfo = NULL;
+			return (error);
+		}
+		fip->fi_readers = fip->fi_writers = 0;
+		wso->so_state |= SS_CANTRCVMORE;
+		rso->so_state |= SS_CANTSENDMORE;
+	}
+	error = 0;
+	if (ap->a_mode & FREAD) {
+		fip->fi_readers++;
+		if (fip->fi_readers == 1) {
+			fip->fi_writesock->so_state &= ~SS_CANTSENDMORE;
+			if (fip->fi_writers > 0)
+				wakeup((caddr_t)&fip->fi_writers);
+		}
+		if (ap->a_mode & O_NONBLOCK)
+			return (0);
+		while (fip->fi_writers == 0) {
+			VOP_UNLOCK(vp);
+			error = tsleep((caddr_t)&fip->fi_readers,
+			    PCATCH | PSOCK, openstr, 0);
+			VOP_LOCK(vp);
+			if (error)
+				break;
+		}
+	} else {
+		fip->fi_writers++;
+		if (fip->fi_readers == 0 && (ap->a_mode & O_NONBLOCK)) {
+			error = ENXIO;
+		} else {
+			if (fip->fi_writers == 1) {
+				fip->fi_readsock->so_state &= ~SS_CANTRCVMORE;
+				if (fip->fi_readers > 0)
+					wakeup((caddr_t)&fip->fi_readers);
+			}
+			while (fip->fi_readers == 0) {
+				VOP_UNLOCK(vp);
+				error = tsleep((caddr_t)&fip->fi_writers,
+				    PCATCH | PSOCK, openstr, 0);
+				VOP_LOCK(vp);
+				if (error)
+					break;
+			}
+		}
+	}
+	if (error)
+		VOP_CLOSE(vp, ap->a_mode, ap->a_cred, ap->a_p);
+	return (error);
+}
+
+/*
+ * Vnode op for read
+ */
+/* ARGSUSED */
+fifo_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	register struct uio *uio = ap->a_uio;
+	register struct socket *rso = ap->a_vp->v_fifoinfo->fi_readsock;
+	int error, startresid;
+
+#ifdef DIAGNOSTIC
+	if (uio->uio_rw != UIO_READ)
+		panic("fifo_read mode");
+#endif
+	if (uio->uio_resid == 0)
+		return (0);
+	if (ap->a_ioflag & IO_NDELAY)
+		rso->so_state |= SS_NBIO;
+	startresid = uio->uio_resid;
+	VOP_UNLOCK(ap->a_vp);
+	error = soreceive(rso, (struct mbuf **)0, uio, (int *)0,
+		(struct mbuf **)0, (struct mbuf **)0);
+	VOP_LOCK(ap->a_vp);
+	/*
+	 * Clear EOF indication after first such return.
+	 */
+	if (uio->uio_resid == startresid)
+		rso->so_state &= ~SS_CANTRCVMORE;
+	if (ap->a_ioflag & IO_NDELAY)
+		rso->so_state &= ~SS_NBIO;
+	return (error);
+}
+
+/*
+ * Vnode op for write
+ */
+/* ARGSUSED */
+fifo_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct socket *wso = ap->a_vp->v_fifoinfo->fi_writesock;
+	int error;
+
+#ifdef DIAGNOSTIC
+	if (ap->a_uio->uio_rw != UIO_WRITE)
+		panic("fifo_write mode");
+#endif
+	if (ap->a_ioflag & IO_NDELAY)
+		wso->so_state |= SS_NBIO;
+	VOP_UNLOCK(ap->a_vp);
+	error = sosend(wso, (struct mbuf *)0, ap->a_uio, 0, (struct mbuf *)0, 0);
+	VOP_LOCK(ap->a_vp);
+	if (ap->a_ioflag & IO_NDELAY)
+		wso->so_state &= ~SS_NBIO;
+	return (error);
+}
+
+/*
+ * Device ioctl operation.
+ */
+/* ARGSUSED */
+fifo_ioctl(ap)
+	struct vop_ioctl_args /* {
+		struct vnode *a_vp;
+		int  a_command;
+		caddr_t  a_data;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct file filetmp;
+
+	if (ap->a_command == FIONBIO)
+		return (0);
+	if (ap->a_fflag & FREAD)
+		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
+	else
+		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
+	return (soo_ioctl(&filetmp, ap->a_command, ap->a_data, ap->a_p));
+}
+
+/* ARGSUSED */
+fifo_select(ap)
+	struct vop_select_args /* {
+		struct vnode *a_vp;
+		int  a_which;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct file filetmp;
+
+	if (ap->a_fflags & FREAD)
+		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_readsock;
+	else
+		filetmp.f_data = (caddr_t)ap->a_vp->v_fifoinfo->fi_writesock;
+	return (soo_select(&filetmp, ap->a_which, ap->a_p));
+}
+
+/*
+ * This is a noop, simply returning what one has been given.
+ */
+fifo_bmap(ap)
+	struct vop_bmap_args /* {
+		struct vnode *a_vp;
+		daddr_t  a_bn;
+		struct vnode **a_vpp;
+		daddr_t *a_bnp;
+	} */ *ap;
+{
+
+	if (ap->a_vpp != NULL)
+		*ap->a_vpp = ap->a_vp;
+	if (ap->a_bnp != NULL)
+		*ap->a_bnp = ap->a_bn;
+	return (0);
+}
+
+/*
+ * At the moment we do not do any locking.
+ */
+/* ARGSUSED */
+fifo_lock(ap)
+	struct vop_lock_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/* ARGSUSED */
+fifo_unlock(ap)
+	struct vop_unlock_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/*
+ * Device close routine
+ */
+/* ARGSUSED */
+fifo_close(ap)
+	struct vop_close_args /* {
+		struct vnode *a_vp;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	register struct fifoinfo *fip = vp->v_fifoinfo;
+	int error1, error2;
+
+	if (ap->a_fflag & FWRITE) {
+		fip->fi_writers--;
+		if (fip->fi_writers == 0)
+			socantrcvmore(fip->fi_readsock);
+	} else {
+		fip->fi_readers--;
+		if (fip->fi_readers == 0)
+			socantsendmore(fip->fi_writesock);
+	}
+	if (vp->v_usecount > 1)
+		return (0);
+	error1 = soclose(fip->fi_readsock);
+	error2 = soclose(fip->fi_writesock);
+	FREE(fip, M_VNODE);
+	vp->v_fifoinfo = NULL;
+	if (error1)
+		return (error1);
+	return (error2);
+}
+
+/*
+ * Print out the contents of a fifo vnode.
+ */
+fifo_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_NON");
+	fifo_printinfo(ap->a_vp);
+	printf("\n");
+}
+
+/*
+ * Print out internal contents of a fifo vnode.
+ */
+fifo_printinfo(vp)
+	struct vnode *vp;
+{
+	register struct fifoinfo *fip = vp->v_fifoinfo;
+
+	printf(", fifo with %d readers and %d writers",
+		fip->fi_readers, fip->fi_writers);
+}
+
+/*
+ * Return POSIX pathconf information applicable to fifo's.
+ */
+fifo_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_PIPE_BUF:
+		*ap->a_retval = PIPE_BUF;
+		return (0);
+	case _PC_CHOWN_RESTRICTED:
+		*ap->a_retval = 1;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Fifo failed operation
+ */
+fifo_ebadf()
+{
+
+	return (EBADF);
+}
+
+/*
+ * Fifo advisory byte-level locks.
+ */
+/* ARGSUSED */
+fifo_advlock(ap)
+	struct vop_advlock_args /* {
+		struct vnode *a_vp;
+		caddr_t  a_id;
+		int  a_op;
+		struct flock *a_fl;
+		int  a_flags;
+	} */ *ap;
+{
+
+	return (EOPNOTSUPP);
+}
+
+/*
+ * Fifo bad operation
+ */
+fifo_badop()
+{
+
+	panic("fifo_badop called");
+	/* NOTREACHED */
+}
diff --git a/sys/miscfs/kernfs/kernfs.h b/sys/miscfs/kernfs/kernfs.h
new file mode 100644
index 0000000..75ddecc
--- /dev/null
+++ b/sys/miscfs/kernfs/kernfs.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)kernfs.h	8.4 (Berkeley) 1/21/94
+ */
+
+#define	_PATH_KERNFS	"/kern"		/* Default mountpoint */
+
+#ifdef KERNEL
+struct kernfs_mount {
+	struct vnode	*kf_root;	/* Root node */
+};
+
+struct kernfs_node {
+	struct kern_target *kf_kt;
+};
+
+#define VFSTOKERNFS(mp)	((struct kernfs_mount *)((mp)->mnt_data))
+#define	VTOKERN(vp) ((struct kernfs_node *)(vp)->v_data)
+
+extern int (**kernfs_vnodeop_p)();
+extern struct vfsops kernfs_vfsops;
+extern struct vnode *rrootvp;
+#endif /* KERNEL */
diff --git a/sys/miscfs/kernfs/kernfs_vfsops.c b/sys/miscfs/kernfs/kernfs_vfsops.c
new file mode 100644
index 0000000..b68d76e
--- /dev/null
+++ b/sys/miscfs/kernfs/kernfs_vfsops.c
@@ -0,0 +1,329 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)kernfs_vfsops.c	8.4 (Berkeley) 1/21/94
+ */
+
+/*
+ * Kernel params Filesystem
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/conf.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+
+#include <miscfs/specfs/specdev.h>
+#include <miscfs/kernfs/kernfs.h>
+
+struct vnode *rrootvp;
+
+/*
+ * Create a vnode for a character device.
+ */
+int
+cdevvp(dev, vpp)
+	dev_t dev;
+	struct vnode **vpp;
+{
+	register struct vnode *vp;
+	struct vnode *nvp;
+	int error;
+
+	if (dev == NODEV)
+		return (0);
+	error = getnewvnode(VT_NON, (struct mount *)0, spec_vnodeop_p, &nvp);
+	if (error) {
+		*vpp = 0;
+		return (error);
+	}
+	vp = nvp;
+	vp->v_type = VCHR;
+	if (nvp = checkalias(vp, dev, (struct mount *)0)) {
+		vput(vp);
+		vp = nvp;
+	}
+	*vpp = vp;
+	return (0);
+}
+
+kernfs_init()
+{
+	int cmaj;
+	int bmaj = major(rootdev);
+	int error = ENXIO;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_init\n");		/* printed during system boot */
+#endif
+
+	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
+		if (cdevsw[cmaj].d_open == bdevsw[bmaj].d_open) {
+			dev_t cdev = makedev(cmaj, minor(rootdev));
+			error = cdevvp(cdev, &rrootvp);
+			if (error == 0)
+				break;
+		}
+	}
+
+	if (error) {
+		printf("kernfs: no raw boot device\n");
+		rrootvp = 0;
+	}
+}
+
+/*
+ * Mount the Kernel params filesystem
+ */
+kernfs_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	int error = 0;
+	u_int size;
+	struct kernfs_mount *fmp;
+	struct vnode *rvp;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_mount(mp = %x)\n", mp);
+#endif
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE)
+		return (EOPNOTSUPP);
+
+	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);	/* XXX */
+	if (error)
+		return (error);
+
+	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
+				M_UFSMNT, M_WAITOK);	/* XXX */
+	rvp->v_type = VDIR;
+	rvp->v_flag |= VROOT;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_mount: root vp = %x\n", rvp);
+#endif
+	fmp->kf_root = rvp;
+	mp->mnt_flag |= MNT_LOCAL;
+	mp->mnt_data = (qaddr_t) fmp;
+	getnewfsid(mp, MOUNT_KERNFS);
+
+	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
+	bcopy("kernfs", mp->mnt_stat.f_mntfromname, sizeof("kernfs"));
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
+#endif
+	return (0);
+}
+
+kernfs_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+	return (0);
+}
+
+kernfs_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	int error;
+	int flags = 0;
+	extern int doforce;
+	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_unmount(mp = %x)\n", mp);
+#endif
+
+	if (mntflags & MNT_FORCE) {
+		/* kernfs can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	/*
+	 * Clear out buffer cache.  I don't think we
+	 * ever get anything cached at this level at the
+	 * moment, but who knows...
+	 */
+	if (rootvp->v_usecount > 1)
+		return (EBUSY);
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_unmount: calling vflush\n");
+#endif
+	if (error = vflush(mp, rootvp, flags))
+		return (error);
+
+#ifdef KERNFS_DIAGNOSTIC
+	vprint("kernfs root", rootvp);
+#endif
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vrele(rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(rootvp);
+	/*
+	 * Finally, throw away the kernfs_mount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+	return 0;
+}
+
+kernfs_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct vnode *vp;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_root(mp = %x)\n", mp);
+#endif
+
+	/*
+	 * Return locked reference to root.
+	 */
+	vp = VFSTOKERNFS(mp)->kf_root;
+	VREF(vp);
+	VOP_LOCK(vp);
+	*vpp = vp;
+	return (0);
+}
+
+kernfs_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+	return (EOPNOTSUPP);
+}
+
+kernfs_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_statfs(mp = %x)\n", mp);
+#endif
+
+	sbp->f_type = MOUNT_KERNFS;
+	sbp->f_flags = 0;
+	sbp->f_bsize = DEV_BSIZE;
+	sbp->f_iosize = DEV_BSIZE;
+	sbp->f_blocks = 2;		/* 1K to keep df happy */
+	sbp->f_bfree = 0;
+	sbp->f_bavail = 0;
+	sbp->f_files = 0;
+	sbp->f_ffree = 0;
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+kernfs_sync(mp, waitfor)
+	struct mount *mp;
+	int waitfor;
+{
+	return (0);
+}
+
+/*
+ * Kernfs flat namespace lookup.
+ * Currently unsupported.
+ */
+kernfs_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+
+kernfs_fhtovp(mp, fhp, setgen, vpp)
+	struct mount *mp;
+	struct fid *fhp;
+	int setgen;
+	struct vnode **vpp;
+{
+	return (EOPNOTSUPP);
+}
+
+kernfs_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+	return (EOPNOTSUPP);
+}
+
+struct vfsops kernfs_vfsops = {
+	kernfs_mount,
+	kernfs_start,
+	kernfs_unmount,
+	kernfs_root,
+	kernfs_quotactl,
+	kernfs_statfs,
+	kernfs_sync,
+	kernfs_vget,
+	kernfs_fhtovp,
+	kernfs_vptofh,
+	kernfs_init,
+};
diff --git a/sys/miscfs/kernfs/kernfs_vnops.c b/sys/miscfs/kernfs/kernfs_vnops.c
new file mode 100644
index 0000000..10b7d7c
--- /dev/null
+++ b/sys/miscfs/kernfs/kernfs_vnops.c
@@ -0,0 +1,759 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)kernfs_vnops.c	8.6 (Berkeley) 2/10/94
+ */
+
+/*
+ * Kernel parameter filesystem (/kern)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/vmmeter.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/malloc.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/buf.h>
+#include <sys/dirent.h>
+#include <miscfs/kernfs/kernfs.h>
+
+#define KSTRING	256		/* Largest I/O available via this filesystem */
+#define	UIO_MX 32
+
+#define	READ_MODE	(S_IRUSR|S_IRGRP|S_IROTH)
+#define	WRITE_MODE	(S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH)
+#define DIR_MODE	(S_IRUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH)
+
+struct kern_target {
+	char *kt_name;
+	void *kt_data;
+#define	KTT_NULL 1
+#define	KTT_TIME 5
+#define KTT_INT	17
+#define	KTT_STRING 31
+#define KTT_HOSTNAME 47
+#define KTT_AVENRUN 53
+	int kt_tag;
+	int kt_rw;
+	int kt_vtype;
+} kern_targets[] = {
+/* NOTE: The name must be less than UIO_MX-16 chars in length */
+	/* name		data		tag		ro/rw */
+	{ ".",		0,		KTT_NULL,	VREAD,		VDIR },
+	{ "..",		0,		KTT_NULL,	VREAD,		VDIR },
+	{ "boottime",	&boottime.tv_sec, KTT_INT,	VREAD,		VREG },
+	{ "copyright",	copyright,	KTT_STRING,	VREAD,		VREG },
+	{ "hostname",	0,		KTT_HOSTNAME,	VREAD|VWRITE,	VREG },
+	{ "hz",		&hz,		KTT_INT,	VREAD,		VREG },
+	{ "loadavg",	0,		KTT_AVENRUN,	VREAD,		VREG },
+	{ "pagesize",	&cnt.v_page_size, KTT_INT,	VREAD,		VREG },
+	{ "physmem",	&physmem,	KTT_INT,	VREAD,		VREG },
+#if 0
+	{ "root",	0,		KTT_NULL,	VREAD,		VDIR },
+#endif
+	{ "rootdev",	0,		KTT_NULL,	VREAD,		VBLK },
+	{ "rrootdev",	0,		KTT_NULL,	VREAD,		VCHR },
+	{ "time",	0,		KTT_TIME,	VREAD,		VREG },
+	{ "version",	version,	KTT_STRING,	VREAD,		VREG },
+};
+
+static int nkern_targets = sizeof(kern_targets) / sizeof(kern_targets[0]);
+
+static int
+kernfs_xread(kt, buf, len, lenp)
+	struct kern_target *kt;
+	char *buf;
+	int len;
+	int *lenp;
+{
+	switch (kt->kt_tag) {
+	case KTT_TIME: {
+		struct timeval tv;
+		microtime(&tv);
+		sprintf(buf, "%d %d\n", tv.tv_sec, tv.tv_usec);
+		break;
+	}
+
+	case KTT_INT: {
+		int *ip = kt->kt_data;
+		sprintf(buf, "%d\n", *ip);
+		break;
+	}
+
+	case KTT_STRING: {
+		char *cp = kt->kt_data;
+		int xlen = strlen(cp) + 1;
+
+		if (xlen >= len)
+			return (EINVAL);
+
+		bcopy(cp, buf, xlen);
+		break;
+	}
+
+	case KTT_HOSTNAME: {
+		char *cp = hostname;
+		int xlen = hostnamelen;
+
+		if (xlen >= (len-2))
+			return (EINVAL);
+
+		bcopy(cp, buf, xlen);
+		buf[xlen] = '\n';
+		buf[xlen+1] = '\0';
+		break;
+	}
+
+	case KTT_AVENRUN:
+		sprintf(buf, "%ld %ld %ld %ld\n",
+				averunnable.ldavg[0],
+				averunnable.ldavg[1],
+				averunnable.ldavg[2],
+				averunnable.fscale);
+		break;
+
+	default:
+		return (EINVAL);
+	}
+
+	*lenp = strlen(buf);
+	return (0);
+}
+
+static int
+kernfs_xwrite(kt, buf, len)
+	struct kern_target *kt;
+	char *buf;
+	int len;
+{
+	switch (kt->kt_tag) {
+	case KTT_HOSTNAME: {
+		if (buf[len-1] == '\n')
+			--len;
+		bcopy(buf, hostname, len);
+		hostname[len] = '\0';
+		hostnamelen = len;
+		return (0);
+	}
+
+	default:
+		return (EIO);
+	}
+}
+
+
+/*
+ * vp is the current namei directory
+ * ndp is the name to locate in that directory...
+ */
+kernfs_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode * a_dvp;
+		struct vnode ** a_vpp;
+		struct componentname * a_cnp;
+	} */ *ap;
+{
+	struct vnode **vpp = ap->a_vpp;
+	struct vnode *dvp = ap->a_dvp;
+	struct componentname *cnp = ap->a_cnp;
+	struct vnode *fvp;
+	int error, i;
+	char *pname;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup(%x)\n", ap);
+	printf("kernfs_lookup(dp = %x, vpp = %x, cnp = %x)\n", dvp, vpp, ap->a_cnp);
+#endif
+	pname = cnp->cn_nameptr;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup(%s)\n", pname);
+#endif
+	if (cnp->cn_namelen == 1 && *pname == '.') {
+		*vpp = dvp;
+		VREF(dvp);
+		/*VOP_LOCK(dvp);*/
+		return (0);
+	}
+
+#if 0
+	if (cnp->cn_namelen == 4 && bcmp(pname, "root", 4) == 0) {
+		*vpp = rootdir;
+		VREF(rootdir);
+		VOP_LOCK(rootdir);
+		return (0);
+	}
+#endif
+
+	/*
+	 * /kern/rootdev is the root device
+	 */
+	if (cnp->cn_namelen == 7 && bcmp(pname, "rootdev", 7) == 0) {
+		*vpp = rootvp;
+		VREF(rootvp);
+		VOP_LOCK(rootvp);
+		return (0);
+	}
+
+	/*
+	 * /kern/rrootdev is the raw root device
+	 */
+	if (cnp->cn_namelen == 8 && bcmp(pname, "rrootdev", 8) == 0) {
+		if (rrootvp) {
+			*vpp = rrootvp;
+			VREF(rrootvp);
+			VOP_LOCK(rrootvp);
+			return (0);
+		}
+		error = ENXIO;
+		goto bad;
+	}
+
+	error = ENOENT;
+
+	for (i = 0; i < nkern_targets; i++) {
+		struct kern_target *kt = &kern_targets[i];
+		if (cnp->cn_namelen == strlen(kt->kt_name) &&
+		    bcmp(kt->kt_name, pname, cnp->cn_namelen) == 0) {
+			error = 0;
+			break;
+		}
+	}
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup: i = %d, error = %d\n", i, error);
+#endif
+
+	if (error)
+		goto bad;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup: allocate new vnode\n");
+#endif
+	error = getnewvnode(VT_KERNFS, dvp->v_mount, kernfs_vnodeop_p, &fvp);
+	if (error)
+		goto bad;
+	MALLOC(fvp->v_data, void *, sizeof(struct kernfs_node), M_TEMP, M_WAITOK);
+	VTOKERN(fvp)->kf_kt = &kern_targets[i];
+	fvp->v_type = VTOKERN(fvp)->kf_kt->kt_vtype;
+	*vpp = fvp;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup: newvp = %x\n", fvp);
+#endif
+	return (0);
+
+bad:;
+	*vpp = NULL;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_lookup: error = %d\n", error);
+#endif
+	return (error);
+}
+
+kernfs_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	/*
+	 * Can always open the root (modulo perms)
+	 */
+	if (vp->v_flag & VROOT)
+		return (0);
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_open, mode = %x, file = %s\n",
+			ap->a_mode, VTOKERN(vp)->kf_kt->kt_name);
+#endif
+
+	if ((ap->a_mode & FWRITE) && !(VTOKERN(vp)->kf_kt->kt_rw & VWRITE))
+		return (EOPNOTSUPP);
+
+	return (0);
+}
+
+static int
+kernfs_access(ap)
+	struct vop_access_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct ucred *cred = ap->a_cred;
+	mode_t mode = ap->a_mode;
+
+	if (mode & VEXEC) {
+		if (vp->v_flag & VROOT)
+			return (0);
+		return (EACCES);
+	}
+
+	if (cred->cr_uid == 0) {
+		if ((vp->v_flag & VROOT) == 0) {
+			struct kern_target *kt = VTOKERN(vp)->kf_kt;
+
+			if ((mode & VWRITE) && !(kt->kt_rw & VWRITE))
+				return (EROFS);
+		}
+		return (0);
+	}
+
+	if (mode & VWRITE)
+		return (EACCES);
+
+	return (0);
+}
+
+
+kernfs_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct vattr *vap = ap->a_vap;
+	int error = 0;
+	char strbuf[KSTRING];
+
+	bzero((caddr_t) vap, sizeof(*vap));
+	vattr_null(vap);
+	vap->va_uid = 0;
+	vap->va_gid = 0;
+	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
+	/* vap->va_qsize = 0; */
+	vap->va_blocksize = DEV_BSIZE;
+	microtime(&vap->va_atime);
+	vap->va_mtime = vap->va_atime;
+	vap->va_ctime = vap->va_ctime;
+	vap->va_gen = 0;
+	vap->va_flags = 0;
+	vap->va_rdev = 0;
+	/* vap->va_qbytes = 0; */
+	vap->va_bytes = 0;
+
+	if (vp->v_flag & VROOT) {
+#ifdef KERNFS_DIAGNOSTIC
+		printf("kernfs_getattr: stat rootdir\n");
+#endif
+		vap->va_type = VDIR;
+		vap->va_mode = DIR_MODE;
+		vap->va_nlink = 2;
+		vap->va_fileid = 2;
+		vap->va_size = DEV_BSIZE;
+	} else {
+		struct kern_target *kt = VTOKERN(vp)->kf_kt;
+		int nbytes;
+#ifdef KERNFS_DIAGNOSTIC
+		printf("kernfs_getattr: stat target %s\n", kt->kt_name);
+#endif
+		vap->va_type = kt->kt_vtype;
+		vap->va_mode = (kt->kt_rw & VWRITE ? WRITE_MODE : READ_MODE);
+		vap->va_nlink = 1;
+		vap->va_fileid = 3 + (kt - kern_targets) / sizeof(*kt);
+		error = kernfs_xread(kt, strbuf, sizeof(strbuf), &nbytes);
+		vap->va_size = nbytes;
+	}
+
+	vp->v_type = vap->va_type;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_getattr: return error %d\n", error);
+#endif
+	return (error);
+}
+
+kernfs_setattr(ap)
+	struct vop_setattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	/*
+	 * Silently ignore attribute changes.
+	 * This allows for open with truncate to have no
+	 * effect until some data is written.  I want to
+	 * do it this way because all writes are atomic.
+	 */
+	return (0);
+}
+
+static int
+kernfs_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct uio *uio = ap->a_uio;
+	struct kern_target *kt;
+	char strbuf[KSTRING];
+	int off = uio->uio_offset;
+	int error, len;
+	char *cp;
+
+	if (vp->v_flag & VROOT)
+		return (EOPNOTSUPP);
+
+	kt = VTOKERN(vp)->kf_kt;
+
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kern_read %s\n", kt->kt_name);
+#endif
+
+	len = 0;
+	error = kernfs_xread(kt, strbuf, sizeof(strbuf), &len);
+	if (error)
+		return (error);
+	cp = strbuf + off;
+	len -= off;
+	return (uiomove(cp, len, uio));
+}
+
+static int
+kernfs_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct uio *uio = ap->a_uio;
+	struct kern_target *kt;
+	int error, xlen;
+	char strbuf[KSTRING];
+
+	if (vp->v_flag & VROOT)
+		return (0);
+
+	kt = VTOKERN(vp)->kf_kt;
+
+	if (uio->uio_offset != 0)
+		return (EINVAL);
+
+	xlen = min(uio->uio_resid, KSTRING-1);
+	error = uiomove(strbuf, xlen, uio);
+	if (error)
+		return (error);
+
+	if (uio->uio_resid != 0)
+		return (EIO);
+
+	strbuf[xlen] = '\0';
+	xlen = strlen(strbuf);
+	return (kernfs_xwrite(kt, strbuf, xlen));
+}
+
+
+kernfs_readdir(ap)
+	struct vop_readdir_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	struct uio *uio = ap->a_uio;
+	int i;
+	int error;
+
+	i = uio->uio_offset / UIO_MX;
+	error = 0;
+	while (uio->uio_resid > 0 && i < nkern_targets) {
+		struct dirent d;
+		struct dirent *dp = &d;
+		struct kern_target *kt = &kern_targets[i];
+#ifdef KERNFS_DIAGNOSTIC
+		printf("kernfs_readdir: i = %d\n", i);
+#endif
+
+		bzero((caddr_t) dp, UIO_MX);
+
+		dp->d_namlen = strlen(kt->kt_name);
+		bcopy(kt->kt_name, dp->d_name, dp->d_namlen+1);
+
+#ifdef KERNFS_DIAGNOSTIC
+		printf("kernfs_readdir: name = %s, len = %d\n",
+				dp->d_name, dp->d_namlen);
+#endif
+		/*
+		 * Fill in the remaining fields
+		 */
+		dp->d_reclen = UIO_MX;
+		dp->d_fileno = i + 3;
+		dp->d_type = DT_UNKNOWN;	/* XXX */
+		/*
+		 * And ship to userland
+		 */
+		error = uiomove((caddr_t) dp, UIO_MX, uio);
+		if (error)
+			break;
+		i++;
+	}
+
+	uio->uio_offset = i * UIO_MX;
+
+	return (error);
+}
+
+kernfs_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	/*
+	 * Clear out the v_type field to avoid
+	 * nasty things happening in vgone().
+	 */
+	vp->v_type = VNON;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_inactive(%x)\n", vp);
+#endif
+	return (0);
+}
+
+kernfs_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+#ifdef KERNFS_DIAGNOSTIC
+	printf("kernfs_reclaim(%x)\n", vp);
+#endif
+	if (vp->v_data) {
+		FREE(vp->v_data, M_TEMP);
+		vp->v_data = 0;
+	}
+	return (0);
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+kernfs_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_MAX_CANON:
+		*ap->a_retval = MAX_CANON;
+		return (0);
+	case _PC_MAX_INPUT:
+		*ap->a_retval = MAX_INPUT;
+		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_VDISABLE:
+		*ap->a_retval = _POSIX_VDISABLE;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Print out the contents of a /dev/fd vnode.
+ */
+/* ARGSUSED */
+kernfs_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_KERNFS, kernfs vnode\n");
+	return (0);
+}
+
+/*void*/
+kernfs_vfree(ap)
+	struct vop_vfree_args /* {
+		struct vnode *a_pvp;
+		ino_t a_ino;
+		int a_mode;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/*
+ * /dev/fd vnode unsupported operation
+ */
+kernfs_enotsupp()
+{
+
+	return (EOPNOTSUPP);
+}
+
+/*
+ * /dev/fd "should never get here" operation
+ */
+kernfs_badop()
+{
+
+	panic("kernfs: bad op");
+	/* NOTREACHED */
+}
+
+/*
+ * kernfs vnode null operation
+ */
+kernfs_nullop()
+{
+
+	return (0);
+}
+
+#define kernfs_create ((int (*) __P((struct  vop_create_args *)))kernfs_enotsupp)
+#define kernfs_mknod ((int (*) __P((struct  vop_mknod_args *)))kernfs_enotsupp)
+#define kernfs_close ((int (*) __P((struct  vop_close_args *)))nullop)
+#define kernfs_ioctl ((int (*) __P((struct  vop_ioctl_args *)))kernfs_enotsupp)
+#define kernfs_select ((int (*) __P((struct  vop_select_args *)))kernfs_enotsupp)
+#define kernfs_mmap ((int (*) __P((struct  vop_mmap_args *)))kernfs_enotsupp)
+#define kernfs_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
+#define kernfs_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
+#define kernfs_remove ((int (*) __P((struct  vop_remove_args *)))kernfs_enotsupp)
+#define kernfs_link ((int (*) __P((struct  vop_link_args *)))kernfs_enotsupp)
+#define kernfs_rename ((int (*) __P((struct  vop_rename_args *)))kernfs_enotsupp)
+#define kernfs_mkdir ((int (*) __P((struct  vop_mkdir_args *)))kernfs_enotsupp)
+#define kernfs_rmdir ((int (*) __P((struct  vop_rmdir_args *)))kernfs_enotsupp)
+#define kernfs_symlink ((int (*) __P((struct vop_symlink_args *)))kernfs_enotsupp)
+#define kernfs_readlink \
+	((int (*) __P((struct  vop_readlink_args *)))kernfs_enotsupp)
+#define kernfs_abortop ((int (*) __P((struct  vop_abortop_args *)))nullop)
+#define kernfs_lock ((int (*) __P((struct  vop_lock_args *)))nullop)
+#define kernfs_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
+#define kernfs_bmap ((int (*) __P((struct  vop_bmap_args *)))kernfs_badop)
+#define kernfs_strategy ((int (*) __P((struct  vop_strategy_args *)))kernfs_badop)
+#define kernfs_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+#define kernfs_advlock ((int (*) __P((struct vop_advlock_args *)))kernfs_enotsupp)
+#define kernfs_blkatoff \
+	((int (*) __P((struct  vop_blkatoff_args *)))kernfs_enotsupp)
+#define kernfs_valloc ((int(*) __P(( \
+		struct vnode *pvp, \
+		int mode, \
+		struct ucred *cred, \
+		struct vnode **vpp))) kernfs_enotsupp)
+#define kernfs_truncate \
+	((int (*) __P((struct  vop_truncate_args *)))kernfs_enotsupp)
+#define kernfs_update ((int (*) __P((struct  vop_update_args *)))kernfs_enotsupp)
+#define kernfs_bwrite ((int (*) __P((struct  vop_bwrite_args *)))kernfs_enotsupp)
+
+int (**kernfs_vnodeop_p)();
+struct vnodeopv_entry_desc kernfs_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, kernfs_lookup },	/* lookup */
+	{ &vop_create_desc, kernfs_create },	/* create */
+	{ &vop_mknod_desc, kernfs_mknod },	/* mknod */
+	{ &vop_open_desc, kernfs_open },	/* open */
+	{ &vop_close_desc, kernfs_close },	/* close */
+	{ &vop_access_desc, kernfs_access },	/* access */
+	{ &vop_getattr_desc, kernfs_getattr },	/* getattr */
+	{ &vop_setattr_desc, kernfs_setattr },	/* setattr */
+	{ &vop_read_desc, kernfs_read },	/* read */
+	{ &vop_write_desc, kernfs_write },	/* write */
+	{ &vop_ioctl_desc, kernfs_ioctl },	/* ioctl */
+	{ &vop_select_desc, kernfs_select },	/* select */
+	{ &vop_mmap_desc, kernfs_mmap },	/* mmap */
+	{ &vop_fsync_desc, kernfs_fsync },	/* fsync */
+	{ &vop_seek_desc, kernfs_seek },	/* seek */
+	{ &vop_remove_desc, kernfs_remove },	/* remove */
+	{ &vop_link_desc, kernfs_link },	/* link */
+	{ &vop_rename_desc, kernfs_rename },	/* rename */
+	{ &vop_mkdir_desc, kernfs_mkdir },	/* mkdir */
+	{ &vop_rmdir_desc, kernfs_rmdir },	/* rmdir */
+	{ &vop_symlink_desc, kernfs_symlink },	/* symlink */
+	{ &vop_readdir_desc, kernfs_readdir },	/* readdir */
+	{ &vop_readlink_desc, kernfs_readlink },/* readlink */
+	{ &vop_abortop_desc, kernfs_abortop },	/* abortop */
+	{ &vop_inactive_desc, kernfs_inactive },/* inactive */
+	{ &vop_reclaim_desc, kernfs_reclaim },	/* reclaim */
+	{ &vop_lock_desc, kernfs_lock },	/* lock */
+	{ &vop_unlock_desc, kernfs_unlock },	/* unlock */
+	{ &vop_bmap_desc, kernfs_bmap },	/* bmap */
+	{ &vop_strategy_desc, kernfs_strategy },/* strategy */
+	{ &vop_print_desc, kernfs_print },	/* print */
+	{ &vop_islocked_desc, kernfs_islocked },/* islocked */
+	{ &vop_pathconf_desc, kernfs_pathconf },/* pathconf */
+	{ &vop_advlock_desc, kernfs_advlock },	/* advlock */
+	{ &vop_blkatoff_desc, kernfs_blkatoff },/* blkatoff */
+	{ &vop_valloc_desc, kernfs_valloc },	/* valloc */
+	{ &vop_vfree_desc, kernfs_vfree },	/* vfree */
+	{ &vop_truncate_desc, kernfs_truncate },/* truncate */
+	{ &vop_update_desc, kernfs_update },	/* update */
+	{ &vop_bwrite_desc, kernfs_bwrite },	/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc kernfs_vnodeop_opv_desc =
+	{ &kernfs_vnodeop_p, kernfs_vnodeop_entries };
diff --git a/sys/miscfs/nullfs/null.h b/sys/miscfs/nullfs/null.h
new file mode 100644
index 0000000..14286ff
--- /dev/null
+++ b/sys/miscfs/nullfs/null.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)null.h	8.2 (Berkeley) 1/21/94
+ *
+ * $Id: lofs.h,v 1.8 1992/05/30 10:05:43 jsp Exp jsp $
+ */
+
+struct null_args {
+	char		*target;	/* Target of loopback  */
+};
+
+struct null_mount {
+	struct mount	*nullm_vfs;
+	struct vnode	*nullm_rootvp;	/* Reference to root null_node */
+};
+
+#ifdef KERNEL
+/*
+ * A cache of vnode references
+ */
+struct null_node {
+	struct null_node	*null_forw;	/* Hash chain */
+	struct null_node	*null_back;
+	struct vnode	        *null_lowervp;	/* VREFed once */
+	struct vnode		*null_vnode;	/* Back pointer */
+};
+
+extern int null_node_create __P((struct mount *mp, struct vnode *target, struct vnode **vpp));
+
+#define	MOUNTTONULLMOUNT(mp) ((struct null_mount *)((mp)->mnt_data))
+#define	VTONULL(vp) ((struct null_node *)(vp)->v_data)
+#define	NULLTOV(xp) ((xp)->null_vnode)
+#ifdef NULLFS_DIAGNOSTIC
+extern struct vnode *null_checkvp __P((struct vnode *vp, char *fil, int lno));
+#define	NULLVPTOLOWERVP(vp) null_checkvp((vp), __FILE__, __LINE__)
+#else
+#define	NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
+#endif
+
+extern int (**null_vnodeop_p)();
+extern struct vfsops null_vfsops;
+#endif /* KERNEL */
diff --git a/sys/miscfs/nullfs/null_subr.c b/sys/miscfs/nullfs/null_subr.c
new file mode 100644
index 0000000..a31723f
--- /dev/null
+++ b/sys/miscfs/nullfs/null_subr.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)null_subr.c	8.4 (Berkeley) 1/21/94
+ *
+ * $Id: lofs_subr.c,v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/nullfs/null.h>
+
+#define LOG2_SIZEVNODE 7		/* log2(sizeof struct vnode) */
+#define	NNULLNODECACHE 16
+#define	NULL_NHASH(vp) ((((u_long)vp)>>LOG2_SIZEVNODE) & (NNULLNODECACHE-1))
+
+/*
+ * Null layer cache:
+ * Each cache entry holds a reference to the lower vnode
+ * along with a pointer to the alias vnode.  When an
+ * entry is added the lower vnode is VREF'd.  When the
+ * alias is removed the lower vnode is vrele'd.
+ */
+
+/*
+ * Cache head
+ */
+struct null_node_cache {
+	struct null_node	*ac_forw;
+	struct null_node	*ac_back;
+};
+
+static struct null_node_cache null_node_cache[NNULLNODECACHE];
+
+/*
+ * Initialise cache headers
+ */
+nullfs_init()
+{
+	struct null_node_cache *ac;
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_init\n");		/* printed during system boot */
+#endif
+
+	for (ac = null_node_cache; ac < null_node_cache + NNULLNODECACHE; ac++)
+		ac->ac_forw = ac->ac_back = (struct null_node *) ac;
+}
+
+/*
+ * Compute hash list for given lower vnode
+ */
+static struct null_node_cache *
+null_node_hash(lowervp)
+struct vnode *lowervp;
+{
+
+	return (&null_node_cache[NULL_NHASH(lowervp)]);
+}
+
+/*
+ * Return a VREF'ed alias for lower vnode if already exists, else 0.
+ */
+static struct vnode *
+null_node_find(mp, lowervp)
+	struct mount *mp;
+	struct vnode *lowervp;
+{
+	struct null_node_cache *hd;
+	struct null_node *a;
+	struct vnode *vp;
+
+	/*
+	 * Find hash base, and then search the (two-way) linked
+	 * list looking for a null_node structure which is referencing
+	 * the lower vnode.  If found, the increment the null_node
+	 * reference count (but NOT the lower vnode's VREF counter).
+	 */
+	hd = null_node_hash(lowervp);
+loop:
+	for (a = hd->ac_forw; a != (struct null_node *) hd; a = a->null_forw) {
+		if (a->null_lowervp == lowervp && NULLTOV(a)->v_mount == mp) {
+			vp = NULLTOV(a);
+			/*
+			 * We need vget for the VXLOCK
+			 * stuff, but we don't want to lock
+			 * the lower node.
+			 */
+			if (vget(vp, 0)) {
+				printf ("null_node_find: vget failed.\n");
+				goto loop;
+			};
+			return (vp);
+		}
+	}
+
+	return NULL;
+}
+
+
+/*
+ * Make a new null_node node.
+ * Vp is the alias vnode, lofsvp is the lower vnode.
+ * Maintain a reference to (lowervp).
+ */
+static int
+null_node_alloc(mp, lowervp, vpp)
+	struct mount *mp;
+	struct vnode *lowervp;
+	struct vnode **vpp;
+{
+	struct null_node_cache *hd;
+	struct null_node *xp;
+	struct vnode *othervp, *vp;
+	int error;
+
+	if (error = getnewvnode(VT_NULL, mp, null_vnodeop_p, vpp))
+		return (error);
+	vp = *vpp;
+
+	MALLOC(xp, struct null_node *, sizeof(struct null_node), M_TEMP, M_WAITOK);
+	vp->v_type = lowervp->v_type;
+	xp->null_vnode = vp;
+	vp->v_data = xp;
+	xp->null_lowervp = lowervp;
+	/*
+	 * Before we insert our new node onto the hash chains,
+	 * check to see if someone else has beaten us to it.
+	 * (We could have slept in MALLOC.)
+	 */
+	if (othervp = null_node_find(lowervp)) {
+		FREE(xp, M_TEMP);
+		vp->v_type = VBAD;	/* node is discarded */
+		vp->v_usecount = 0;	/* XXX */
+		*vpp = othervp;
+		return 0;
+	};
+	VREF(lowervp);   /* Extra VREF will be vrele'd in null_node_create */
+	hd = null_node_hash(lowervp);
+	insque(xp, hd);
+	return 0;
+}
+
+
+/*
+ * Try to find an existing null_node vnode refering
+ * to it, otherwise make a new null_node vnode which
+ * contains a reference to the lower vnode.
+ */
+int
+null_node_create(mp, lowervp, newvpp)
+	struct mount *mp;
+	struct vnode *lowervp;
+	struct vnode **newvpp;
+{
+	struct vnode *aliasvp;
+
+	if (aliasvp = null_node_find(mp, lowervp)) {
+		/*
+		 * null_node_find has taken another reference
+		 * to the alias vnode.
+		 */
+#ifdef NULLFS_DIAGNOSTIC
+		vprint("null_node_create: exists", NULLTOV(ap));
+#endif
+		/* VREF(aliasvp); --- done in null_node_find */
+	} else {
+		int error;
+
+		/*
+		 * Get new vnode.
+		 */
+#ifdef NULLFS_DIAGNOSTIC
+		printf("null_node_create: create new alias vnode\n");
+#endif
+
+		/*
+		 * Make new vnode reference the null_node.
+		 */
+		if (error = null_node_alloc(mp, lowervp, &aliasvp))
+			return error;
+
+		/*
+		 * aliasvp is already VREF'd by getnewvnode()
+		 */
+	}
+
+	vrele(lowervp);
+
+#ifdef DIAGNOSTIC
+	if (lowervp->v_usecount < 1) {
+		/* Should never happen... */
+		vprint ("null_node_create: alias ");
+		vprint ("null_node_create: lower ");
+		printf ("null_node_create: lower has 0 usecount.\n");
+		panic ("null_node_create: lower has 0 usecount.");
+	};
+#endif
+
+#ifdef NULLFS_DIAGNOSTIC
+	vprint("null_node_create: alias", aliasvp);
+	vprint("null_node_create: lower", lowervp);
+#endif
+
+	*newvpp = aliasvp;
+	return (0);
+}
+#ifdef NULLFS_DIAGNOSTIC
+struct vnode *
+null_checkvp(vp, fil, lno)
+	struct vnode *vp;
+	char *fil;
+	int lno;
+{
+	struct null_node *a = VTONULL(vp);
+#ifdef notyet
+	/*
+	 * Can't do this check because vop_reclaim runs
+	 * with a funny vop vector.
+	 */
+	if (vp->v_op != null_vnodeop_p) {
+		printf ("null_checkvp: on non-null-node\n");
+		while (null_checkvp_barrier) /*WAIT*/ ;
+		panic("null_checkvp");
+	};
+#endif
+	if (a->null_lowervp == NULL) {
+		/* Should never happen */
+		int i; u_long *p;
+		printf("vp = %x, ZERO ptr\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (null_checkvp_barrier) /*WAIT*/ ;
+		panic("null_checkvp");
+	}
+	if (a->null_lowervp->v_usecount < 1) {
+		int i; u_long *p;
+		printf("vp = %x, unref'ed lowervp\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (null_checkvp_barrier) /*WAIT*/ ;
+		panic ("null with unref'ed lowervp");
+	};
+#ifdef notyet
+	printf("null %x/%d -> %x/%d [%s, %d]\n",
+	        NULLTOV(a), NULLTOV(a)->v_usecount,
+		a->null_lowervp, a->null_lowervp->v_usecount,
+		fil, lno);
+#endif
+	return a->null_lowervp;
+}
+#endif
diff --git a/sys/miscfs/nullfs/null_vfsops.c b/sys/miscfs/nullfs/null_vfsops.c
new file mode 100644
index 0000000..b0d2df7
--- /dev/null
+++ b/sys/miscfs/nullfs/null_vfsops.c
@@ -0,0 +1,366 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)null_vfsops.c	8.2 (Berkeley) 1/21/94
+ *
+ * @(#)lofs_vfsops.c	1.2 (Berkeley) 6/18/92
+ * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $
+ */
+
+/*
+ * Null Layer
+ * (See null_vnops.c for a description of what this does.)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/nullfs/null.h>
+
+/*
+ * Mount null layer
+ */
+int
+nullfs_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	int error = 0;
+	struct null_args args;
+	struct vnode *lowerrootvp, *vp;
+	struct vnode *nullm_rootvp;
+	struct null_mount *xmp;
+	u_int size;
+
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_mount(mp = %x)\n", mp);
+#endif
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE) {
+		return (EOPNOTSUPP);
+		/* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/
+	}
+
+	/*
+	 * Get argument
+	 */
+	if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args)))
+		return (error);
+
+	/*
+	 * Find lower node
+	 */
+	NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
+		UIO_USERSPACE, args.target, p);
+	if (error = namei(ndp))
+		return (error);
+
+	/*
+	 * Sanity check on lower vnode
+	 */
+	lowerrootvp = ndp->ni_vp;
+
+	vrele(ndp->ni_dvp);
+	ndp->ni_dvp = NULL;
+
+	xmp = (struct null_mount *) malloc(sizeof(struct null_mount),
+				M_UFSMNT, M_WAITOK);	/* XXX */
+
+	/*
+	 * Save reference to underlying FS
+	 */
+	xmp->nullm_vfs = lowerrootvp->v_mount;
+
+	/*
+	 * Save reference.  Each mount also holds
+	 * a reference on the root vnode.
+	 */
+	error = null_node_create(mp, lowerrootvp, &vp);
+	/*
+	 * Unlock the node (either the lower or the alias)
+	 */
+	VOP_UNLOCK(vp);
+	/*
+	 * Make sure the node alias worked
+	 */
+	if (error) {
+		vrele(lowerrootvp);
+		free(xmp, M_UFSMNT);	/* XXX */
+		return (error);
+	}
+
+	/*
+	 * Keep a held reference to the root vnode.
+	 * It is vrele'd in nullfs_unmount.
+	 */
+	nullm_rootvp = vp;
+	nullm_rootvp->v_flag |= VROOT;
+	xmp->nullm_rootvp = nullm_rootvp;
+	if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
+		mp->mnt_flag |= MNT_LOCAL;
+	mp->mnt_data = (qaddr_t) xmp;
+	getnewfsid(mp, MOUNT_LOFS);
+
+	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 
+	    &size);
+	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_mount: lower %s, alias at %s\n",
+		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
+#endif
+	return (0);
+}
+
+/*
+ * VFS start.  Nothing needed here - the start routine
+ * on the underlying filesystem will have been called
+ * when that filesystem was mounted.
+ */
+int
+nullfs_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+	return (0);
+	/* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */
+}
+
+/*
+ * Free reference to null layer
+ */
+int
+nullfs_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
+	int error;
+	int flags = 0;
+	extern int doforce;
+
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_unmount(mp = %x)\n", mp);
+#endif
+
+	if (mntflags & MNT_FORCE) {
+		/* lofs can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	/*
+	 * Clear out buffer cache.  I don't think we
+	 * ever get anything cached at this level at the
+	 * moment, but who knows...
+	 */
+#if 0
+	mntflushbuf(mp, 0); 
+	if (mntinvalbuf(mp, 1))
+		return (EBUSY);
+#endif
+	if (nullm_rootvp->v_usecount > 1)
+		return (EBUSY);
+	if (error = vflush(mp, nullm_rootvp, flags))
+		return (error);
+
+#ifdef NULLFS_DIAGNOSTIC
+	vprint("alias root of lower", nullm_rootvp);
+#endif	 
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vrele(nullm_rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(nullm_rootvp);
+	/*
+	 * Finally, throw away the null_mount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+	return 0;
+}
+
+int
+nullfs_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct vnode *vp;
+
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp,
+			MOUNTTONULLMOUNT(mp)->nullm_rootvp,
+			NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
+			);
+#endif
+
+	/*
+	 * Return locked reference to root.
+	 */
+	vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp;
+	VREF(vp);
+	VOP_LOCK(vp);
+	*vpp = vp;
+	return 0;
+}
+
+int
+nullfs_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+	return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p);
+}
+
+int
+nullfs_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+	int error;
+	struct statfs mstat;
+
+#ifdef NULLFS_DIAGNOSTIC
+	printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp,
+			MOUNTTONULLMOUNT(mp)->nullm_rootvp,
+			NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp)
+			);
+#endif
+
+	bzero(&mstat, sizeof(mstat));
+
+	error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p);
+	if (error)
+		return (error);
+
+	/* now copy across the "interesting" information and fake the rest */
+	sbp->f_type = mstat.f_type;
+	sbp->f_flags = mstat.f_flags;
+	sbp->f_bsize = mstat.f_bsize;
+	sbp->f_iosize = mstat.f_iosize;
+	sbp->f_blocks = mstat.f_blocks;
+	sbp->f_bfree = mstat.f_bfree;
+	sbp->f_bavail = mstat.f_bavail;
+	sbp->f_files = mstat.f_files;
+	sbp->f_ffree = mstat.f_ffree;
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+int
+nullfs_sync(mp, waitfor, cred, p)
+	struct mount *mp;
+	int waitfor;
+	struct ucred *cred;
+	struct proc *p;
+{
+	/*
+	 * XXX - Assumes no data cached at null layer.
+	 */
+	return (0);
+}
+
+int
+nullfs_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+	
+	return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp);
+}
+
+int
+nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
+	struct mount *mp;
+	struct fid *fidp;
+	struct mbuf *nam;
+	struct vnode **vpp;
+	int *exflagsp;
+	struct ucred**credanonp;
+{
+
+	return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp);
+}
+
+int
+nullfs_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+	return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp);
+}
+
+int nullfs_init __P((void));
+
+struct vfsops null_vfsops = {
+	nullfs_mount,
+	nullfs_start,
+	nullfs_unmount,
+	nullfs_root,
+	nullfs_quotactl,
+	nullfs_statfs,
+	nullfs_sync,
+	nullfs_vget,
+	nullfs_fhtovp,
+	nullfs_vptofh,
+	nullfs_init,
+};
diff --git a/sys/miscfs/nullfs/null_vnops.c b/sys/miscfs/nullfs/null_vnops.c
new file mode 100644
index 0000000..115ff6f
--- /dev/null
+++ b/sys/miscfs/nullfs/null_vnops.c
@@ -0,0 +1,462 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * John Heidemann of the UCLA Ficus project.
+ *
+ * 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.
+ *
+ *	@(#)null_vnops.c	8.1 (Berkeley) 6/10/93
+ *
+ * Ancestors:
+ *	@(#)lofs_vnops.c	1.2 (Berkeley) 6/18/92
+ *	$Id: lofs_vnops.c,v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
+ *	...and...
+ *	@(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project
+ */
+
+/*
+ * Null Layer
+ *
+ * (See mount_null(8) for more information.)
+ *
+ * The null layer duplicates a portion of the file system
+ * name space under a new name.  In this respect, it is
+ * similar to the loopback file system.  It differs from
+ * the loopback fs in two respects:  it is implemented using
+ * a stackable layers techniques, and it's "null-node"s stack above
+ * all lower-layer vnodes, not just over directory vnodes.
+ *
+ * The null layer has two purposes.  First, it serves as a demonstration
+ * of layering by proving a layer which does nothing.  (It actually
+ * does everything the loopback file system does, which is slightly
+ * more than nothing.)  Second, the null layer can serve as a prototype
+ * layer.  Since it provides all necessary layer framework,
+ * new file system layers can be created very easily be starting
+ * with a null layer.
+ *
+ * The remainder of this man page examines the null layer as a basis
+ * for constructing new layers.
+ *
+ *
+ * INSTANTIATING NEW NULL LAYERS
+ *
+ * New null layers are created with mount_null(8).
+ * Mount_null(8) takes two arguments, the pathname
+ * of the lower vfs (target-pn) and the pathname where the null
+ * layer will appear in the namespace (alias-pn).  After
+ * the null layer is put into place, the contents
+ * of target-pn subtree will be aliased under alias-pn.
+ *
+ *
+ * OPERATION OF A NULL LAYER
+ *
+ * The null layer is the minimum file system layer,
+ * simply bypassing all possible operations to the lower layer
+ * for processing there.  The majority of its activity centers
+ * on the bypass routine, though which nearly all vnode operations
+ * pass.
+ *
+ * The bypass routine accepts arbitrary vnode operations for
+ * handling by the lower layer.  It begins by examing vnode
+ * operation arguments and replacing any null-nodes by their
+ * lower-layer equivlants.  It then invokes the operation
+ * on the lower layer.  Finally, it replaces the null-nodes
+ * in the arguments and, if a vnode is return by the operation,
+ * stacks a null-node on top of the returned vnode.
+ *
+ * Although bypass handles most operations, 
+ * vop_getattr, _inactive, _reclaim, and _print are not bypassed.
+ * Vop_getattr must change the fsid being returned.
+ * Vop_inactive and vop_reclaim are not bypassed so that
+ * they can handle freeing null-layer specific data.
+ * Vop_print is not bypassed to avoid excessive debugging
+ * information.
+ *
+ *
+ * INSTANTIATING VNODE STACKS
+ *
+ * Mounting associates the null layer with a lower layer,
+ * effect stacking two VFSes.  Vnode stacks are instead
+ * created on demand as files are accessed.
+ *
+ * The initial mount creates a single vnode stack for the
+ * root of the new null layer.  All other vnode stacks
+ * are created as a result of vnode operations on
+ * this or other null vnode stacks.
+ *
+ * New vnode stacks come into existance as a result of
+ * an operation which returns a vnode.  
+ * The bypass routine stacks a null-node above the new
+ * vnode before returning it to the caller.
+ *
+ * For example, imagine mounting a null layer with
+ * "mount_null /usr/include /dev/layer/null".
+ * Changing directory to /dev/layer/null will assign
+ * the root null-node (which was created when the null layer was mounted).
+ * Now consider opening "sys".  A vop_lookup would be
+ * done on the root null-node.  This operation would bypass through
+ * to the lower layer which would return a vnode representing 
+ * the UFS "sys".  Null_bypass then builds a null-node
+ * aliasing the UFS "sys" and returns this to the caller.
+ * Later operations on the null-node "sys" will repeat this
+ * process when constructing other vnode stacks.
+ *
+ *
+ * CREATING OTHER FILE SYSTEM LAYERS
+ *
+ * One of the easiest ways to construct new file system layers is to make
+ * a copy of the null layer, rename all files and variables, and
+ * then begin modifing the copy.  Sed can be used to easily rename
+ * all variables.
+ *
+ * The umap layer is an example of a layer descended from the 
+ * null layer.
+ *
+ *
+ * INVOKING OPERATIONS ON LOWER LAYERS
+ *
+ * There are two techniques to invoke operations on a lower layer 
+ * when the operation cannot be completely bypassed.  Each method
+ * is appropriate in different situations.  In both cases,
+ * it is the responsibility of the aliasing layer to make
+ * the operation arguments "correct" for the lower layer
+ * by mapping an vnode arguments to the lower layer.
+ *
+ * The first approach is to call the aliasing layer's bypass routine.
+ * This method is most suitable when you wish to invoke the operation
+ * currently being hanldled on the lower layer.  It has the advantage
+ * that the bypass routine already must do argument mapping.
+ * An example of this is null_getattrs in the null layer.
+ *
+ * A second approach is to directly invoked vnode operations on
+ * the lower layer with the VOP_OPERATIONNAME interface.
+ * The advantage of this method is that it is easy to invoke
+ * arbitrary operations on the lower layer.  The disadvantage
+ * is that vnodes arguments must be manualy mapped.
+ *
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+#include <miscfs/nullfs/null.h>
+
+
+int null_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
+
+/*
+ * This is the 10-Apr-92 bypass routine.
+ *    This version has been optimized for speed, throwing away some
+ * safety checks.  It should still always work, but it's not as
+ * robust to programmer errors.
+ *    Define SAFETY to include some error checking code.
+ *
+ * In general, we map all vnodes going down and unmap them on the way back.
+ * As an exception to this, vnodes can be marked "unmapped" by setting
+ * the Nth bit in operation's vdesc_flags.
+ *
+ * Also, some BSD vnode operations have the side effect of vrele'ing
+ * their arguments.  With stacking, the reference counts are held
+ * by the upper node, not the lower one, so we must handle these
+ * side-effects here.  This is not of concern in Sun-derived systems
+ * since there are no such side-effects.
+ *
+ * This makes the following assumptions:
+ * - only one returned vpp
+ * - no INOUT vpp's (Sun's vop_open has one of these)
+ * - the vnode operation vector of the first vnode should be used
+ *   to determine what implementation of the op should be invoked
+ * - all mapped vnodes are of our vnode-type (NEEDSWORK:
+ *   problems on rmdir'ing mount points and renaming?)
+ */ 
+int
+null_bypass(ap)
+	struct vop_generic_args /* {
+		struct vnodeop_desc *a_desc;
+		<other random data follows, presumably>
+	} */ *ap;
+{
+	extern int (**null_vnodeop_p)();  /* not extern, really "forward" */
+	register struct vnode **this_vp_p;
+	int error;
+	struct vnode *old_vps[VDESC_MAX_VPS];
+	struct vnode **vps_p[VDESC_MAX_VPS];
+	struct vnode ***vppp;
+	struct vnodeop_desc *descp = ap->a_desc;
+	int reles, i;
+
+	if (null_bug_bypass)
+		printf ("null_bypass: %s\n", descp->vdesc_name);
+
+#ifdef SAFETY
+	/*
+	 * We require at least one vp.
+	 */
+	if (descp->vdesc_vp_offsets == NULL ||
+	    descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
+		panic ("null_bypass: no vp's in map.\n");
+#endif
+
+	/*
+	 * Map the vnodes going in.
+	 * Later, we'll invoke the operation based on
+	 * the first mapped vnode's operation vector.
+	 */
+	reles = descp->vdesc_flags;
+	for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
+		if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
+			break;   /* bail out at end of list */
+		vps_p[i] = this_vp_p = 
+			VOPARG_OFFSETTO(struct vnode**,descp->vdesc_vp_offsets[i],ap);
+		/*
+		 * We're not guaranteed that any but the first vnode
+		 * are of our type.  Check for and don't map any
+		 * that aren't.  (We must always map first vp or vclean fails.)
+		 */
+		if (i && (*this_vp_p)->v_op != null_vnodeop_p) {
+			old_vps[i] = NULL;
+		} else {
+			old_vps[i] = *this_vp_p;
+			*(vps_p[i]) = NULLVPTOLOWERVP(*this_vp_p);
+			/*
+			 * XXX - Several operations have the side effect
+			 * of vrele'ing their vp's.  We must account for
+			 * that.  (This should go away in the future.)
+			 */
+			if (reles & 1)
+				VREF(*this_vp_p);
+		}
+			
+	}
+
+	/*
+	 * Call the operation on the lower layer
+	 * with the modified argument structure.
+	 */
+	error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
+
+	/*
+	 * Maintain the illusion of call-by-value
+	 * by restoring vnodes in the argument structure
+	 * to their original value.
+	 */
+	reles = descp->vdesc_flags;
+	for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
+		if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
+			break;   /* bail out at end of list */
+		if (old_vps[i]) {
+			*(vps_p[i]) = old_vps[i];
+			if (reles & 1)
+				vrele(*(vps_p[i]));
+		}
+	}
+
+	/*
+	 * Map the possible out-going vpp
+	 * (Assumes that the lower layer always returns
+	 * a VREF'ed vpp unless it gets an error.)
+	 */
+	if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
+	    !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
+	    !error) {
+		/*
+		 * XXX - even though some ops have vpp returned vp's,
+		 * several ops actually vrele this before returning.
+		 * We must avoid these ops.
+		 * (This should go away when these ops are regularized.)
+		 */
+		if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
+			goto out;
+		vppp = VOPARG_OFFSETTO(struct vnode***,
+				 descp->vdesc_vpp_offset,ap);
+		error = null_node_create(old_vps[0]->v_mount, **vppp, *vppp);
+	}
+
+ out:
+	return (error);
+}
+
+
+/*
+ *  We handle getattr only to change the fsid.
+ */
+int
+null_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	int error;
+	if (error = null_bypass(ap))
+		return (error);
+	/* Requires that arguments be restored. */
+	ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
+	return (0);
+}
+
+
+int
+null_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	/*
+	 * Do nothing (and _don't_ bypass).
+	 * Wait to vrele lowervp until reclaim,
+	 * so that until then our null_node is in the
+	 * cache and reusable.
+	 *
+	 * NEEDSWORK: Someday, consider inactive'ing
+	 * the lowervp and then trying to reactivate it
+	 * with capabilities (v_id)
+	 * like they do in the name lookup cache code.
+	 * That's too much work for now.
+	 */
+	return (0);
+}
+
+int
+null_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct null_node *xp = VTONULL(vp);
+	struct vnode *lowervp = xp->null_lowervp;
+
+	/*
+	 * Note: in vop_reclaim, vp->v_op == dead_vnodeop_p,
+	 * so we can't call VOPs on ourself.
+	 */
+	/* After this assignment, this node will not be re-used. */
+	xp->null_lowervp = NULL;
+	remque(xp);
+	FREE(vp->v_data, M_TEMP);
+	vp->v_data = NULL;
+	vrele (lowervp);
+	return (0);
+}
+
+
+int
+null_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	printf ("\ttag VT_NULLFS, vp=%x, lowervp=%x\n", vp, NULLVPTOLOWERVP(vp));
+	return (0);
+}
+
+
+/*
+ * XXX - vop_strategy must be hand coded because it has no
+ * vnode in its arguments.
+ * This goes away with a merged VM/buffer cache.
+ */
+int
+null_strategy(ap)
+	struct vop_strategy_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+	struct buf *bp = ap->a_bp;
+	int error;
+	struct vnode *savedvp;
+
+	savedvp = bp->b_vp;
+	bp->b_vp = NULLVPTOLOWERVP(bp->b_vp);
+
+	error = VOP_STRATEGY(bp);
+
+	bp->b_vp = savedvp;
+
+	return (error);
+}
+
+
+/*
+ * XXX - like vop_strategy, vop_bwrite must be hand coded because it has no
+ * vnode in its arguments.
+ * This goes away with a merged VM/buffer cache.
+ */
+int
+null_bwrite(ap)
+	struct vop_bwrite_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+	struct buf *bp = ap->a_bp;
+	int error;
+	struct vnode *savedvp;
+
+	savedvp = bp->b_vp;
+	bp->b_vp = NULLVPTOLOWERVP(bp->b_vp);
+
+	error = VOP_BWRITE(bp);
+
+	bp->b_vp = savedvp;
+
+	return (error);
+}
+
+/*
+ * Global vfs data structures
+ */
+int (**null_vnodeop_p)();
+struct vnodeopv_entry_desc null_vnodeop_entries[] = {
+	{ &vop_default_desc, null_bypass },
+
+	{ &vop_getattr_desc, null_getattr },
+	{ &vop_inactive_desc, null_inactive },
+	{ &vop_reclaim_desc, null_reclaim },
+	{ &vop_print_desc, null_print },
+
+	{ &vop_strategy_desc, null_strategy },
+	{ &vop_bwrite_desc, null_bwrite },
+
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc null_vnodeop_opv_desc =
+	{ &null_vnodeop_p, null_vnodeop_entries };
diff --git a/sys/miscfs/portal/portal.h b/sys/miscfs/portal/portal.h
new file mode 100644
index 0000000..38d7ee0
--- /dev/null
+++ b/sys/miscfs/portal/portal.h
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)portal.h	8.4 (Berkeley) 1/21/94
+ *
+ * $Id: portal.h,v 1.3 1992/05/30 10:05:24 jsp Exp jsp $
+ */
+
+struct portal_args {
+	char		*pa_config;	/* Config file */
+	int		pa_socket;	/* Socket to server */
+};
+
+struct portal_cred {
+	int		pcr_flag;		/* File open mode */
+	uid_t		pcr_uid;		/* From ucred */
+	short		pcr_ngroups;		/* From ucred */
+	gid_t		pcr_groups[NGROUPS];	/* From ucred */
+};
+
+#ifdef KERNEL
+struct portalmount {
+	struct vnode	*pm_root;	/* Root node */
+	struct file	*pm_server;	/* Held reference to server socket */
+};
+
+struct portalnode {
+	int		pt_size;	/* Length of Arg */
+	char		*pt_arg;	/* Arg to send to server */
+	int		pt_fileid;	/* cookie */
+};
+
+#define VFSTOPORTAL(mp)	((struct portalmount *)((mp)->mnt_data))
+#define	VTOPORTAL(vp) ((struct portalnode *)(vp)->v_data)
+
+#define PORTAL_ROOTFILEID	2
+
+extern int (**portal_vnodeop_p)();
+extern struct vfsops portal_vfsops;
+#endif /* KERNEL */
diff --git a/sys/miscfs/portal/portal_vfsops.c b/sys/miscfs/portal/portal_vfsops.c
new file mode 100644
index 0000000..39e8563
--- /dev/null
+++ b/sys/miscfs/portal/portal_vfsops.c
@@ -0,0 +1,313 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)portal_vfsops.c	8.6 (Berkeley) 1/21/94
+ *
+ * $Id: portal_vfsops.c,v 1.5 1992/05/30 10:25:27 jsp Exp jsp $
+ */
+
+/*
+ * Portal Filesystem
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+#include <sys/filedesc.h>
+#include <sys/file.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+#include <sys/domain.h>
+#include <sys/un.h>
+#include <miscfs/portal/portal.h>
+
+int
+portal_init()
+{
+
+	return (0);
+}
+
+/*
+ * Mount the per-process file descriptors (/dev/fd)
+ */
+int
+portal_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	struct file *fp;
+	struct portal_args args;
+	struct portalmount *fmp;
+	struct socket *so;
+	struct vnode *rvp;
+	u_int size;
+	int error;
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE)
+		return (EOPNOTSUPP);
+
+	if (error = copyin(data, (caddr_t) &args, sizeof(struct portal_args)))
+		return (error);
+
+	if (error = getsock(p->p_fd, args.pa_socket, &fp))
+		return (error);
+	so = (struct socket *) fp->f_data;
+	if (so->so_proto->pr_domain->dom_family != AF_UNIX)
+		return (ESOCKTNOSUPPORT);
+
+	error = getnewvnode(VT_PORTAL, mp, portal_vnodeop_p, &rvp); /* XXX */
+	if (error)
+		return (error);
+	MALLOC(rvp->v_data, void *, sizeof(struct portalnode),
+		M_TEMP, M_WAITOK);
+
+	fmp = (struct portalmount *) malloc(sizeof(struct portalmount),
+				 M_UFSMNT, M_WAITOK);	/* XXX */
+	rvp->v_type = VDIR;
+	rvp->v_flag |= VROOT;
+	VTOPORTAL(rvp)->pt_arg = 0;
+	VTOPORTAL(rvp)->pt_size = 0;
+	VTOPORTAL(rvp)->pt_fileid = PORTAL_ROOTFILEID;
+	fmp->pm_root = rvp;
+	fmp->pm_server = fp; fp->f_count++;
+
+	mp->mnt_flag |= MNT_LOCAL;
+	mp->mnt_data = (qaddr_t) fmp;
+	getnewfsid(mp, MOUNT_PORTAL);
+
+	(void)copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+	(void)copyinstr(args.pa_config,
+	    mp->mnt_stat.f_mntfromname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
+
+#ifdef notdef
+	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
+	bcopy("portal", mp->mnt_stat.f_mntfromname, sizeof("portal"));
+#endif
+
+	return (0);
+}
+
+int
+portal_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+
+	return (0);
+}
+
+int
+portal_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	extern int doforce;
+	struct vnode *rootvp = VFSTOPORTAL(mp)->pm_root;
+	int error, flags = 0;
+
+
+	if (mntflags & MNT_FORCE) {
+		/* portal can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	/*
+	 * Clear out buffer cache.  I don't think we
+	 * ever get anything cached at this level at the
+	 * moment, but who knows...
+	 */
+#ifdef notyet
+	mntflushbuf(mp, 0); 
+	if (mntinvalbuf(mp, 1))
+		return (EBUSY);
+#endif
+	if (rootvp->v_usecount > 1)
+		return (EBUSY);
+	if (error = vflush(mp, rootvp, flags))
+		return (error);
+
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vrele(rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(rootvp);
+	/*
+	 * Shutdown the socket.  This will cause the select in the
+	 * daemon to wake up, and then the accept will get ECONNABORTED
+	 * which it interprets as a request to go and bury itself.
+	 */
+	soshutdown((struct socket *) VFSTOPORTAL(mp)->pm_server->f_data, 2);
+	/*
+	 * Discard reference to underlying file.  Must call closef because
+	 * this may be the last reference.
+	 */
+	closef(VFSTOPORTAL(mp)->pm_server, (struct proc *) 0);
+	/*
+	 * Finally, throw away the portalmount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+	return (0);
+}
+
+int
+portal_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct vnode *vp;
+
+
+	/*
+	 * Return locked reference to root.
+	 */
+	vp = VFSTOPORTAL(mp)->pm_root;
+	VREF(vp);
+	VOP_LOCK(vp);
+	*vpp = vp;
+	return (0);
+}
+
+int
+portal_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+portal_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+
+	sbp->f_type = MOUNT_PORTAL;
+	sbp->f_flags = 0;
+	sbp->f_bsize = DEV_BSIZE;
+	sbp->f_iosize = DEV_BSIZE;
+	sbp->f_blocks = 2;		/* 1K to keep df happy */
+	sbp->f_bfree = 0;
+	sbp->f_bavail = 0;
+	sbp->f_files = 1;		/* Allow for "." */
+	sbp->f_ffree = 0;		/* See comments above */
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+int
+portal_sync(mp, waitfor)
+	struct mount *mp;
+	int waitfor;
+{
+
+	return (0);
+}
+
+int
+portal_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+portal_fhtovp(mp, fhp, vpp)
+	struct mount *mp;
+	struct fid *fhp;
+	struct vnode **vpp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+portal_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+struct vfsops portal_vfsops = {
+	portal_mount,
+	portal_start,
+	portal_unmount,
+	portal_root,
+	portal_quotactl,
+	portal_statfs,
+	portal_sync,
+	portal_vget,
+	portal_fhtovp,
+	portal_vptofh,
+	portal_init,
+};
diff --git a/sys/miscfs/portal/portal_vnops.c b/sys/miscfs/portal/portal_vnops.c
new file mode 100644
index 0000000..5e17026
--- /dev/null
+++ b/sys/miscfs/portal/portal_vnops.c
@@ -0,0 +1,707 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)portal_vnops.c	8.8 (Berkeley) 1/21/94
+ *
+ * $Id: portal_vnops.c,v 1.4 1992/05/30 10:05:24 jsp Exp jsp $
+ */
+
+/*
+ * Portal Filesystem
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/proc.h>
+#include <sys/filedesc.h>
+#include <sys/vnode.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <sys/mount.h>
+#include <sys/malloc.h>
+#include <sys/namei.h>
+#include <sys/mbuf.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/un.h>
+#include <sys/unpcb.h>
+#include <miscfs/portal/portal.h>
+
+static int portal_fileid = PORTAL_ROOTFILEID+1;
+
+static void
+portal_closefd(p, fd)
+	struct proc *p;
+	int fd;
+{
+	int error;
+	struct {
+		int fd;
+	} ua;
+	int rc;
+
+	ua.fd = fd;
+	error = close(p, &ua, &rc);
+	/*
+	 * We should never get an error, and there isn't anything
+	 * we could do if we got one, so just print a message.
+	 */
+	if (error)
+		printf("portal_closefd: error = %d\n", error);
+}
+
+/*
+ * vp is the current namei directory
+ * cnp is the name to locate in that directory...
+ */
+int
+portal_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode * a_dvp;
+		struct vnode ** a_vpp;
+		struct componentname * a_cnp;
+	} */ *ap;
+{
+	char *pname = ap->a_cnp->cn_nameptr;
+	struct portalnode *pt;
+	int error;
+	struct vnode *fvp = 0;
+	char *path;
+	int size;
+
+	if (ap->a_cnp->cn_namelen == 1 && *pname == '.') {
+		*ap->a_vpp = ap->a_dvp;
+		VREF(ap->a_dvp);
+		/*VOP_LOCK(ap->a_dvp);*/
+		return (0);
+	}
+
+
+	error = getnewvnode(VT_PORTAL, ap->a_dvp->v_mount, portal_vnodeop_p, &fvp);
+	if (error)
+		goto bad;
+	fvp->v_type = VREG;
+	MALLOC(fvp->v_data, void *, sizeof(struct portalnode),
+		M_TEMP, M_WAITOK);
+
+	pt = VTOPORTAL(fvp);
+	/*
+	 * Save all of the remaining pathname and
+	 * advance the namei next pointer to the end
+	 * of the string.
+	 */
+	for (size = 0, path = pname; *path; path++)
+		size++;
+	ap->a_cnp->cn_consume = size - ap->a_cnp->cn_namelen;
+
+	pt->pt_arg = malloc(size+1, M_TEMP, M_WAITOK);
+	pt->pt_size = size+1;
+	bcopy(pname, pt->pt_arg, pt->pt_size);
+	pt->pt_fileid = portal_fileid++;
+
+	*ap->a_vpp = fvp;
+	/*VOP_LOCK(fvp);*/
+	return (0);
+
+bad:;
+	if (fvp) {
+		vrele(fvp);
+	}
+	*ap->a_vpp = NULL;
+	return (error);
+}
+
+static int
+portal_connect(so, so2)
+	struct socket *so;
+	struct socket *so2;
+{
+	/* from unp_connect, bypassing the namei stuff... */
+	struct socket *so3;
+	struct unpcb *unp2;
+	struct unpcb *unp3;
+
+	if (so2 == 0)
+		return (ECONNREFUSED);
+
+	if (so->so_type != so2->so_type)
+		return (EPROTOTYPE);
+
+	if ((so2->so_options & SO_ACCEPTCONN) == 0)
+		return (ECONNREFUSED);
+
+	if ((so3 = sonewconn(so2, 0)) == 0)
+		return (ECONNREFUSED);
+
+	unp2 = sotounpcb(so2);
+	unp3 = sotounpcb(so3);
+	if (unp2->unp_addr)
+		unp3->unp_addr = m_copy(unp2->unp_addr, 0, (int)M_COPYALL);
+
+	so2 = so3;
+
+
+	return (unp_connect2(so, so2));
+}
+
+int
+portal_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct socket *so = 0;
+	struct portalnode *pt;
+	struct proc *p = ap->a_p;
+	struct vnode *vp = ap->a_vp;
+	int s;
+	struct uio auio;
+	struct iovec aiov[2];
+	int res;
+	struct mbuf *cm = 0;
+	struct cmsghdr *cmsg;
+	int newfds;
+	int *ip;
+	int fd;
+	int error;
+	int len;
+	struct portalmount *fmp;
+	struct file *fp;
+	struct portal_cred pcred;
+
+	/*
+	 * Nothing to do when opening the root node.
+	 */
+	if (vp->v_flag & VROOT)
+		return (0);
+
+	/*
+	 * Can't be opened unless the caller is set up
+	 * to deal with the side effects.  Check for this
+	 * by testing whether the p_dupfd has been set.
+	 */
+	if (p->p_dupfd >= 0)
+		return (ENODEV);
+
+	pt = VTOPORTAL(vp);
+	fmp = VFSTOPORTAL(vp->v_mount);
+
+	/*
+	 * Create a new socket.
+	 */
+	error = socreate(AF_UNIX, &so, SOCK_STREAM, 0);
+	if (error)
+		goto bad;
+
+	/*
+	 * Reserve some buffer space
+	 */
+	res = pt->pt_size + sizeof(pcred) + 512;	/* XXX */
+	error = soreserve(so, res, res);
+	if (error)
+		goto bad;
+
+	/*
+	 * Kick off connection
+	 */
+	error = portal_connect(so, (struct socket *)fmp->pm_server->f_data);
+	if (error)
+		goto bad;
+
+	/*
+	 * Wait for connection to complete
+	 */
+	/*
+	 * XXX: Since the mount point is holding a reference on the
+	 * underlying server socket, it is not easy to find out whether
+	 * the server process is still running.  To handle this problem
+	 * we loop waiting for the new socket to be connected (something
+	 * which will only happen if the server is still running) or for
+	 * the reference count on the server socket to drop to 1, which
+	 * will happen if the server dies.  Sleep for 5 second intervals
+	 * and keep polling the reference count.   XXX.
+	 */
+	s = splnet();
+	while ((so->so_state & SS_ISCONNECTING) && so->so_error == 0) {
+		if (fmp->pm_server->f_count == 1) {
+			error = ECONNREFUSED;
+			splx(s);
+			goto bad;
+		}
+		(void) tsleep((caddr_t) &so->so_timeo, PSOCK, "portalcon", 5 * hz);
+	}
+	splx(s);
+
+	if (so->so_error) {
+		error = so->so_error;
+		goto bad;
+	}
+		
+	/*
+	 * Set miscellaneous flags
+	 */
+	so->so_rcv.sb_timeo = 0;
+	so->so_snd.sb_timeo = 0;
+	so->so_rcv.sb_flags |= SB_NOINTR;
+	so->so_snd.sb_flags |= SB_NOINTR;
+
+
+	pcred.pcr_flag = ap->a_mode;
+	pcred.pcr_uid = ap->a_cred->cr_uid;
+	pcred.pcr_ngroups = ap->a_cred->cr_ngroups;
+	bcopy(ap->a_cred->cr_groups, pcred.pcr_groups, NGROUPS * sizeof(gid_t));
+	aiov[0].iov_base = (caddr_t) &pcred;
+	aiov[0].iov_len = sizeof(pcred);
+	aiov[1].iov_base = pt->pt_arg;
+	aiov[1].iov_len = pt->pt_size;
+	auio.uio_iov = aiov;
+	auio.uio_iovcnt = 2;
+	auio.uio_rw = UIO_WRITE;
+	auio.uio_segflg = UIO_SYSSPACE;
+	auio.uio_procp = p;
+	auio.uio_offset = 0;
+	auio.uio_resid = aiov[0].iov_len + aiov[1].iov_len;
+
+	error = sosend(so, (struct mbuf *) 0, &auio,
+			(struct mbuf *) 0, (struct mbuf *) 0, 0);
+	if (error)
+		goto bad;
+
+	len = auio.uio_resid = sizeof(int);
+	do {
+		struct mbuf *m = 0;
+		int flags = MSG_WAITALL;
+		error = soreceive(so, (struct mbuf **) 0, &auio,
+					&m, &cm, &flags);
+		if (error)
+			goto bad;
+
+		/*
+		 * Grab an error code from the mbuf.
+		 */
+		if (m) {
+			m = m_pullup(m, sizeof(int));	/* Needed? */
+			if (m) {
+				error = *(mtod(m, int *));
+				m_freem(m);
+			} else {
+				error = EINVAL;
+			}
+		} else {
+			if (cm == 0) {
+				error = ECONNRESET;	 /* XXX */
+#ifdef notdef
+				break;
+#endif
+			}
+		}
+	} while (cm == 0 && auio.uio_resid == len && !error);
+
+	if (cm == 0)
+		goto bad;
+
+	if (auio.uio_resid) {
+		error = 0;
+#ifdef notdef
+		error = EMSGSIZE;
+		goto bad;
+#endif
+	}
+
+	/*
+	 * XXX: Break apart the control message, and retrieve the
+	 * received file descriptor.  Note that more than one descriptor
+	 * may have been received, or that the rights chain may have more
+	 * than a single mbuf in it.  What to do?
+	 */
+	cmsg = mtod(cm, struct cmsghdr *);
+	newfds = (cmsg->cmsg_len - sizeof(*cmsg)) / sizeof (int);
+	if (newfds == 0) {
+		error = ECONNREFUSED;
+		goto bad;
+	}
+	/*
+	 * At this point the rights message consists of a control message
+	 * header, followed by a data region containing a vector of
+	 * integer file descriptors.  The fds were allocated by the action
+	 * of receiving the control message.
+	 */
+	ip = (int *) (cmsg + 1);
+	fd = *ip++;
+	if (newfds > 1) {
+		/*
+		 * Close extra fds.
+		 */
+		int i;
+		printf("portal_open: %d extra fds\n", newfds - 1);
+		for (i = 1; i < newfds; i++) {
+			portal_closefd(p, *ip);
+			ip++;
+		}
+	}
+
+	/*
+	 * Check that the mode the file is being opened for is a subset 
+	 * of the mode of the existing descriptor.
+	 */
+ 	fp = p->p_fd->fd_ofiles[fd];
+	if (((ap->a_mode & (FREAD|FWRITE)) | fp->f_flag) != fp->f_flag) {
+		portal_closefd(p, fd);
+		error = EACCES;
+		goto bad;
+	}
+
+	/*
+	 * Save the dup fd in the proc structure then return the
+	 * special error code (ENXIO) which causes magic things to
+	 * happen in vn_open.  The whole concept is, well, hmmm.
+	 */
+	p->p_dupfd = fd;
+	error = ENXIO;
+
+bad:;
+	/*
+	 * And discard the control message.
+	 */
+	if (cm) { 
+		m_freem(cm);
+	}
+
+	if (so) {
+		soshutdown(so, 2);
+		soclose(so);
+	}
+	return (error);
+}
+
+int
+portal_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct vattr *vap = ap->a_vap;
+
+	bzero(vap, sizeof(*vap));
+	vattr_null(vap);
+	vap->va_uid = 0;
+	vap->va_gid = 0;
+	vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
+	vap->va_size = DEV_BSIZE;
+	vap->va_blocksize = DEV_BSIZE;
+	microtime(&vap->va_atime);
+	vap->va_mtime = vap->va_atime;
+	vap->va_ctime = vap->va_ctime;
+	vap->va_gen = 0;
+	vap->va_flags = 0;
+	vap->va_rdev = 0;
+	/* vap->va_qbytes = 0; */
+	vap->va_bytes = 0;
+	/* vap->va_qsize = 0; */
+	if (vp->v_flag & VROOT) {
+		vap->va_type = VDIR;
+		vap->va_mode = S_IRUSR|S_IWUSR|S_IXUSR|
+				S_IRGRP|S_IWGRP|S_IXGRP|
+				S_IROTH|S_IWOTH|S_IXOTH;
+		vap->va_nlink = 2;
+		vap->va_fileid = 2;
+	} else {
+		vap->va_type = VREG;
+		vap->va_mode = S_IRUSR|S_IWUSR|
+				S_IRGRP|S_IWGRP|
+				S_IROTH|S_IWOTH;
+		vap->va_nlink = 1;
+		vap->va_fileid = VTOPORTAL(vp)->pt_fileid;
+	}
+	return (0);
+}
+
+int
+portal_setattr(ap)
+	struct vop_setattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	/*
+	 * Can't mess with the root vnode
+	 */
+	if (ap->a_vp->v_flag & VROOT)
+		return (EACCES);
+
+	return (0);
+}
+
+/*
+ * Fake readdir, just return empty directory.
+ * It is hard to deal with '.' and '..' so don't bother.
+ */
+int
+portal_readdir(ap)
+	struct vop_readdir_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+int
+portal_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+int
+portal_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct portalnode *pt = VTOPORTAL(ap->a_vp);
+
+	if (pt->pt_arg) {
+		free((caddr_t) pt->pt_arg, M_TEMP);
+		pt->pt_arg = 0;
+	}
+	FREE(ap->a_vp->v_data, M_TEMP);
+	ap->a_vp->v_data = 0;
+
+	return (0);
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+portal_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_MAX_CANON:
+		*ap->a_retval = MAX_CANON;
+		return (0);
+	case _PC_MAX_INPUT:
+		*ap->a_retval = MAX_INPUT;
+		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_VDISABLE:
+		*ap->a_retval = _POSIX_VDISABLE;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Print out the contents of a Portal vnode.
+ */
+/* ARGSUSED */
+int
+portal_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_PORTAL, portal vnode\n");
+	return (0);
+}
+
+/*void*/
+int
+portal_vfree(ap)
+	struct vop_vfree_args /* {
+		struct vnode *a_pvp;
+		ino_t a_ino;
+		int a_mode;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+
+/*
+ * Portal vnode unsupported operation
+ */
+int
+portal_enotsupp()
+{
+
+	return (EOPNOTSUPP);
+}
+
+/*
+ * Portal "should never get here" operation
+ */
+int
+portal_badop()
+{
+
+	panic("portal: bad op");
+	/* NOTREACHED */
+}
+
+/*
+ * Portal vnode null operation
+ */
+int
+portal_nullop()
+{
+
+	return (0);
+}
+
+#define portal_create ((int (*) __P((struct vop_create_args *)))portal_enotsupp)
+#define portal_mknod ((int (*) __P((struct  vop_mknod_args *)))portal_enotsupp)
+#define portal_close ((int (*) __P((struct  vop_close_args *)))nullop)
+#define portal_access ((int (*) __P((struct  vop_access_args *)))nullop)
+#define portal_read ((int (*) __P((struct  vop_read_args *)))portal_enotsupp)
+#define portal_write ((int (*) __P((struct  vop_write_args *)))portal_enotsupp)
+#define portal_ioctl ((int (*) __P((struct  vop_ioctl_args *)))portal_enotsupp)
+#define portal_select ((int (*) __P((struct vop_select_args *)))portal_enotsupp)
+#define portal_mmap ((int (*) __P((struct  vop_mmap_args *)))portal_enotsupp)
+#define portal_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
+#define portal_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
+#define portal_remove ((int (*) __P((struct vop_remove_args *)))portal_enotsupp)
+#define portal_link ((int (*) __P((struct  vop_link_args *)))portal_enotsupp)
+#define portal_rename ((int (*) __P((struct vop_rename_args *)))portal_enotsupp)
+#define portal_mkdir ((int (*) __P((struct  vop_mkdir_args *)))portal_enotsupp)
+#define portal_rmdir ((int (*) __P((struct  vop_rmdir_args *)))portal_enotsupp)
+#define portal_symlink \
+	((int (*) __P((struct  vop_symlink_args *)))portal_enotsupp)
+#define portal_readlink \
+	((int (*) __P((struct  vop_readlink_args *)))portal_enotsupp)
+#define portal_abortop ((int (*) __P((struct  vop_abortop_args *)))nullop)
+#define portal_lock ((int (*) __P((struct  vop_lock_args *)))nullop)
+#define portal_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
+#define portal_bmap ((int (*) __P((struct  vop_bmap_args *)))portal_badop)
+#define portal_strategy \
+	((int (*) __P((struct  vop_strategy_args *)))portal_badop)
+#define portal_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+#define portal_advlock \
+	((int (*) __P((struct  vop_advlock_args *)))portal_enotsupp)
+#define portal_blkatoff \
+	((int (*) __P((struct  vop_blkatoff_args *)))portal_enotsupp)
+#define portal_valloc ((int(*) __P(( \
+		struct vnode *pvp, \
+		int mode, \
+		struct ucred *cred, \
+		struct vnode **vpp))) portal_enotsupp)
+#define portal_truncate \
+	((int (*) __P((struct  vop_truncate_args *)))portal_enotsupp)
+#define portal_update ((int (*) __P((struct vop_update_args *)))portal_enotsupp)
+#define portal_bwrite ((int (*) __P((struct vop_bwrite_args *)))portal_enotsupp)
+
+int (**portal_vnodeop_p)();
+struct vnodeopv_entry_desc portal_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, portal_lookup },		/* lookup */
+	{ &vop_create_desc, portal_create },		/* create */
+	{ &vop_mknod_desc, portal_mknod },		/* mknod */
+	{ &vop_open_desc, portal_open },		/* open */
+	{ &vop_close_desc, portal_close },		/* close */
+	{ &vop_access_desc, portal_access },		/* access */
+	{ &vop_getattr_desc, portal_getattr },		/* getattr */
+	{ &vop_setattr_desc, portal_setattr },		/* setattr */
+	{ &vop_read_desc, portal_read },		/* read */
+	{ &vop_write_desc, portal_write },		/* write */
+	{ &vop_ioctl_desc, portal_ioctl },		/* ioctl */
+	{ &vop_select_desc, portal_select },		/* select */
+	{ &vop_mmap_desc, portal_mmap },		/* mmap */
+	{ &vop_fsync_desc, portal_fsync },		/* fsync */
+	{ &vop_seek_desc, portal_seek },		/* seek */
+	{ &vop_remove_desc, portal_remove },		/* remove */
+	{ &vop_link_desc, portal_link },		/* link */
+	{ &vop_rename_desc, portal_rename },		/* rename */
+	{ &vop_mkdir_desc, portal_mkdir },		/* mkdir */
+	{ &vop_rmdir_desc, portal_rmdir },		/* rmdir */
+	{ &vop_symlink_desc, portal_symlink },		/* symlink */
+	{ &vop_readdir_desc, portal_readdir },		/* readdir */
+	{ &vop_readlink_desc, portal_readlink },	/* readlink */
+	{ &vop_abortop_desc, portal_abortop },		/* abortop */
+	{ &vop_inactive_desc, portal_inactive },	/* inactive */
+	{ &vop_reclaim_desc, portal_reclaim },		/* reclaim */
+	{ &vop_lock_desc, portal_lock },		/* lock */
+	{ &vop_unlock_desc, portal_unlock },		/* unlock */
+	{ &vop_bmap_desc, portal_bmap },		/* bmap */
+	{ &vop_strategy_desc, portal_strategy },	/* strategy */
+	{ &vop_print_desc, portal_print },		/* print */
+	{ &vop_islocked_desc, portal_islocked },	/* islocked */
+	{ &vop_pathconf_desc, portal_pathconf },	/* pathconf */
+	{ &vop_advlock_desc, portal_advlock },		/* advlock */
+	{ &vop_blkatoff_desc, portal_blkatoff },	/* blkatoff */
+	{ &vop_valloc_desc, portal_valloc },		/* valloc */
+	{ &vop_vfree_desc, portal_vfree },		/* vfree */
+	{ &vop_truncate_desc, portal_truncate },	/* truncate */
+	{ &vop_update_desc, portal_update },		/* update */
+	{ &vop_bwrite_desc, portal_bwrite },		/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc portal_vnodeop_opv_desc =
+	{ &portal_vnodeop_p, portal_vnodeop_entries };
diff --git a/sys/miscfs/procfs/README b/sys/miscfs/procfs/README
new file mode 100644
index 0000000..38811b3
--- /dev/null
+++ b/sys/miscfs/procfs/README
@@ -0,0 +1,113 @@
+saute procfs lyonnais
+
+procfs supports two levels of directory.  the filesystem root
+directory contains a representation of the system process table.
+this consists of an entry for each active and zombie process, and
+an additional entry "curproc" which always represents the process
+making the lookup request.
+
+each of the sub-directories contains several files.  these files
+are used to control and interrogate processes.  the files implemented
+are:
+
+	file	- xxx.  the exec'ed file.
+
+	status  - r/o.  returns process status.
+
+	ctl	- w/o.  sends a control message to the process.
+			for example:
+				echo hup > /proc/curproc/note
+			will send a SIGHUP to the shell.
+			whereas
+				echo attach > /proc/1293/ctl
+			would set up process 1293 for debugging.
+			see below for more details.
+
+	mem	- r/w.  virtual memory image of the process.
+			parts of the address space are readable
+			only if they exist in the target process.
+			a more reasonable alternative might be
+			to return zero pages instead of an error.
+			comments?
+
+	note	- w/o.  writing a string here sends the
+			equivalent note to the process.
+			[ not implemented. ]
+
+	notepg	- w/o.  the same as note, but sends to all
+			members of the process group.
+			[ not implemented. ]
+
+	regs	- r/w.	process register set.  this can be read
+			or written any time even if the process
+			is not stopped.  since the bsd kernel
+			is single-processor, this implementation
+			will get the "right" register values.
+			a multi-proc kernel would need to do some
+			synchronisation.
+
+this then looks like:
+
+% ls -li /proc
+total 0
+   9 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 0
+  17 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 1
+  89 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 10
+  25 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 2
+2065 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 257
+2481 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 309
+ 265 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 32
+3129 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 390
+3209 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 400
+3217 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 401
+3273 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 408
+ 393 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 48
+ 409 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 50
+ 465 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 57
+ 481 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 59
+ 537 dr-xr-xr-x  2 root  kmem   0 Sep 21 15:06 66
+ 545 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 67
+ 657 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 81
+ 665 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 82
+ 673 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 83
+ 681 dr-xr-xr-x  2 root  wheel  0 Sep 21 15:06 84
+3273 dr-xr-xr-x  2 jsp   staff  0 Sep 21 15:06 curproc
+% ls -li /proc/curproc
+total 408
+3341 --w-------  1 jsp  staff       0 Sep 21 15:06 ctl
+1554 -r-xr-xr-x  1 bin  bin     90112 Mar 29 04:52 file
+3339 -rw-------  1 jsp  staff  118784 Sep 21 15:06 mem
+3343 --w-------  1 jsp  staff       0 Sep 21 15:06 note
+3344 --w-------  1 jsp  staff       0 Sep 21 15:06 notepg
+3340 -rw-------  1 jsp  staff       0 Sep 21 15:06 regs
+3342 -r--r--r--  1 jsp  staff       0 Sep 21 15:06 status
+% df /proc/curproc /proc/curproc/file
+Filesystem  512-blocks    Used   Avail Capacity  Mounted on
+proc                 2       2       0   100%    /proc
+/dev/wd0a        16186   13548    1018    93%    /
+% cat /proc/curproc/status
+cat 446 439 400 81 12,0 ctty 748620684 270000 0 0 0 20000 nochan 11 20 20 20 0 21 117
+
+
+
+the basic sequence of commands written to "ctl" would be
+
+	attach		- this stops the target process and
+			  arranges for the sending process
+			  to become the debug control process
+	wait		- wait for the target process to come to
+			  a steady state ready for debugging.
+	step		- single step, with no signal delivery.
+	run		- continue running, with no signal delivery,
+			  until next trap or breakpoint.
+	<signame>	- deliver signal <signame> and continue running.
+	detach		- continue execution of the target process
+			  and remove it from control by the debug process
+
+in a normal debugging environment, where the target is fork/exec'd by
+the debugger, the debugger should fork and the child should stop itself
+(with a self-inflicted SIGSTOP).  the parent should do a "wait" then an
+"attach".  as before, the child will hit a breakpoint on the first
+instruction in any newly exec'd image.
+
+$Id: README,v 3.1 1993/12/15 09:40:17 jsp Exp $
diff --git a/sys/miscfs/procfs/procfs.h b/sys/miscfs/procfs/procfs.h
new file mode 100644
index 0000000..f7b8fa3
--- /dev/null
+++ b/sys/miscfs/procfs/procfs.h
@@ -0,0 +1,186 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs.h	8.6 (Berkeley) 2/3/94
+ *
+ * From:
+ *	$Id: procfs.h,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+/*
+ * The different types of node in a procfs filesystem
+ */
+typedef enum {
+	Proot,		/* the filesystem root */
+	Pproc,		/* a process-specific sub-directory */
+	Pfile,		/* the executable file */
+	Pmem,		/* the process's memory image */
+	Pregs,		/* the process's register set */
+	Pfpregs,	/* the process's FP register set */
+	Pctl,		/* process control */
+	Pstatus,	/* process status */
+	Pnote,		/* process notifier */
+	Pnotepg		/* process group notifier */
+} pfstype;
+
+/*
+ * control data for the proc file system.
+ */
+struct pfsnode {
+	struct pfsnode	*pfs_next;	/* next on list */
+	struct vnode	*pfs_vnode;	/* vnode associated with this pfsnode */
+	pfstype		pfs_type;	/* type of procfs node */
+	pid_t		pfs_pid;	/* associated process */
+	u_short		pfs_mode;	/* mode bits for stat() */
+	u_long		pfs_flags;	/* open flags */
+	u_long		pfs_fileno;	/* unique file id */
+};
+
+#define PROCFS_NOTELEN	64	/* max length of a note (/proc/$pid/note) */
+#define PROCFS_CTLLEN 	8	/* max length of a ctl msg (/proc/$pid/ctl */
+
+/*
+ * Kernel stuff follows
+ */
+#ifdef KERNEL
+#define CNEQ(cnp, s, len) \
+	 ((cnp)->cn_namelen == (len) && \
+	  (bcmp((s), (cnp)->cn_nameptr, (len)) == 0))
+
+/*
+ * Format of a directory entry in /proc, ...
+ * This must map onto struct dirent (see <dirent.h>)
+ */
+#define PROCFS_NAMELEN 8
+struct pfsdent {
+	u_long	d_fileno;
+	u_short	d_reclen;
+	u_char	d_type;
+	u_char	d_namlen;
+	char	d_name[PROCFS_NAMELEN];
+};
+#define UIO_MX sizeof(struct pfsdent)
+#define PROCFS_FILENO(pid, type) \
+	(((type) == Proot) ? \
+			2 : \
+			((((pid)+1) << 3) + ((int) (type))))
+
+/*
+ * Convert between pfsnode vnode
+ */
+#define VTOPFS(vp)	((struct pfsnode *)(vp)->v_data)
+#define PFSTOV(pfs)	((pfs)->pfs_vnode)
+
+typedef struct vfs_namemap vfs_namemap_t;
+struct vfs_namemap {
+	const char *nm_name;
+	int nm_val;
+};
+
+extern int vfs_getuserstr __P((struct uio *, char *, int *));
+extern vfs_namemap_t *vfs_findname __P((vfs_namemap_t *, char *, int));
+
+/* <machine/reg.h> */
+struct reg;
+struct fpreg;
+
+#define PFIND(pid) ((pid) ? pfind(pid) : &proc0)
+extern int procfs_freevp __P((struct vnode *));
+extern int procfs_allocvp __P((struct mount *, struct vnode **, long, pfstype));
+extern struct vnode *procfs_findtextvp __P((struct proc *));
+extern int procfs_sstep __P((struct proc *));
+extern void procfs_fix_sstep __P((struct proc *));
+extern int procfs_read_regs __P((struct proc *, struct reg *));
+extern int procfs_write_regs __P((struct proc *, struct reg *));
+extern int procfs_read_fpregs __P((struct proc *, struct fpreg *));
+extern int procfs_write_fpregs __P((struct proc *, struct fpreg *));
+extern int procfs_donote __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+extern int procfs_doregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+extern int procfs_dofpregs __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+extern int procfs_domem __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+extern int procfs_doctl __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+extern int procfs_dostatus __P((struct proc *, struct proc *, struct pfsnode *pfsp, struct uio *uio));
+
+#define PROCFS_LOCKED	0x01
+#define PROCFS_WANT	0x02
+
+extern int (**procfs_vnodeop_p)();
+extern struct vfsops procfs_vfsops;
+
+/*
+ * Prototypes for procfs vnode ops
+ */
+int	procfs_badop();	/* varargs */
+int	procfs_rw __P((struct vop_read_args *));
+int	procfs_lookup __P((struct vop_lookup_args *));
+#define procfs_create ((int (*) __P((struct vop_create_args *))) procfs_badop)
+#define procfs_mknod ((int (*) __P((struct vop_mknod_args *))) procfs_badop)
+int	procfs_open __P((struct vop_open_args *));
+int	procfs_close __P((struct vop_close_args *));
+int	procfs_access __P((struct vop_access_args *));
+int	procfs_getattr __P((struct vop_getattr_args *));
+int	procfs_setattr __P((struct vop_setattr_args *));
+#define	procfs_read procfs_rw
+#define	procfs_write procfs_rw
+int	procfs_ioctl __P((struct vop_ioctl_args *));
+#define procfs_select ((int (*) __P((struct vop_select_args *))) procfs_badop)
+#define procfs_mmap ((int (*) __P((struct vop_mmap_args *))) procfs_badop)
+#define procfs_fsync ((int (*) __P((struct vop_fsync_args *))) procfs_badop)
+#define procfs_seek ((int (*) __P((struct vop_seek_args *))) procfs_badop)
+#define procfs_remove ((int (*) __P((struct vop_remove_args *))) procfs_badop)
+#define procfs_link ((int (*) __P((struct vop_link_args *))) procfs_badop)
+#define procfs_rename ((int (*) __P((struct vop_rename_args *))) procfs_badop)
+#define procfs_mkdir ((int (*) __P((struct vop_mkdir_args *))) procfs_badop)
+#define procfs_rmdir ((int (*) __P((struct vop_rmdir_args *))) procfs_badop)
+#define procfs_symlink ((int (*) __P((struct vop_symlink_args *))) procfs_badop)
+int	procfs_readdir __P((struct vop_readdir_args *));
+#define procfs_readlink ((int (*) __P((struct vop_readlink_args *))) procfs_badop)
+int	procfs_abortop __P((struct vop_abortop_args *));
+int	procfs_inactive __P((struct vop_inactive_args *));
+int	procfs_reclaim __P((struct vop_reclaim_args *));
+#define procfs_lock ((int (*) __P((struct vop_lock_args *))) nullop)
+#define procfs_unlock ((int (*) __P((struct vop_unlock_args *))) nullop)
+int	procfs_bmap __P((struct vop_bmap_args *));
+#define	procfs_strategy ((int (*) __P((struct vop_strategy_args *))) procfs_badop)
+int	procfs_print __P((struct vop_print_args *));
+#define procfs_islocked ((int (*) __P((struct vop_islocked_args *))) nullop)
+#define procfs_advlock ((int (*) __P((struct vop_advlock_args *))) procfs_badop)
+#define procfs_blkatoff ((int (*) __P((struct vop_blkatoff_args *))) procfs_badop)
+#define procfs_valloc ((int (*) __P((struct vop_valloc_args *))) procfs_badop)
+#define procfs_vfree ((int (*) __P((struct vop_vfree_args *))) nullop)
+#define procfs_truncate ((int (*) __P((struct vop_truncate_args *))) procfs_badop)
+#define procfs_update ((int (*) __P((struct vop_update_args *))) nullop)
+#endif /* KERNEL */
diff --git a/sys/miscfs/procfs/procfs_ctl.c b/sys/miscfs/procfs/procfs_ctl.c
new file mode 100644
index 0000000..a42a03c
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_ctl.c
@@ -0,0 +1,302 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_ctl.c	8.3 (Berkeley) 1/21/94
+ *
+ * From:
+ *	$Id: procfs_ctl.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/ioctl.h>
+#include <sys/tty.h>
+#include <sys/resource.h>
+#include <sys/resourcevar.h>
+#include <miscfs/procfs/procfs.h>
+
+/*
+ * True iff process (p) is in trace wait state
+ * relative to process (curp)
+ */
+#define TRACE_WAIT_P(curp, p) \
+	((p)->p_stat == SSTOP && \
+	 (p)->p_pptr == (curp) && \
+	 ((p)->p_flag & P_TRACED))
+
+#ifdef notdef
+#define FIX_SSTEP(p) { \
+		procfs_fix_sstep(p); \
+	} \
+}
+#else
+#define FIX_SSTEP(p)
+#endif
+
+#define PROCFS_CTL_ATTACH	1
+#define PROCFS_CTL_DETACH	2
+#define PROCFS_CTL_STEP		3
+#define PROCFS_CTL_RUN		4
+#define PROCFS_CTL_WAIT		5
+
+static vfs_namemap_t ctlnames[] = {
+	/* special /proc commands */
+	{ "attach",	PROCFS_CTL_ATTACH },
+	{ "detach",	PROCFS_CTL_DETACH },
+	{ "step",	PROCFS_CTL_STEP },
+	{ "run",	PROCFS_CTL_RUN },
+	{ "wait",	PROCFS_CTL_WAIT },
+	{ 0 },
+};
+
+static vfs_namemap_t signames[] = {
+	/* regular signal names */
+	{ "hup",	SIGHUP },	{ "int",	SIGINT },
+	{ "quit",	SIGQUIT },	{ "ill",	SIGILL },
+	{ "trap",	SIGTRAP },	{ "abrt",	SIGABRT },
+	{ "iot",	SIGIOT },	{ "emt",	SIGEMT },
+	{ "fpe",	SIGFPE },	{ "kill",	SIGKILL },
+	{ "bus",	SIGBUS },	{ "segv",	SIGSEGV },
+	{ "sys",	SIGSYS },	{ "pipe",	SIGPIPE },
+	{ "alrm",	SIGALRM },	{ "term",	SIGTERM },
+	{ "urg",	SIGURG },	{ "stop",	SIGSTOP },
+	{ "tstp",	SIGTSTP },	{ "cont",	SIGCONT },
+	{ "chld",	SIGCHLD },	{ "ttin",	SIGTTIN },
+	{ "ttou",	SIGTTOU },	{ "io",		SIGIO },
+	{ "xcpu",	SIGXCPU },	{ "xfsz",	SIGXFSZ },
+	{ "vtalrm",	SIGVTALRM },	{ "prof",	SIGPROF },
+	{ "winch",	SIGWINCH },	{ "info",	SIGINFO },
+	{ "usr1",	SIGUSR1 },	{ "usr2",	SIGUSR2 },
+	{ 0 },
+};
+
+static int
+procfs_control(curp, p, op)
+	struct proc *curp;
+	struct proc *p;
+	int op;
+{
+	int error;
+
+	/*
+	 * Attach - attaches the target process for debugging
+	 * by the calling process.
+	 */
+	if (op == PROCFS_CTL_ATTACH) {
+		/* check whether already being traced */
+		if (p->p_flag & P_TRACED)
+			return (EBUSY);
+
+		/* can't trace yourself! */
+		if (p->p_pid == curp->p_pid)
+			return (EINVAL);
+
+		/*
+		 * Go ahead and set the trace flag.
+		 * Save the old parent (it's reset in
+		 *   _DETACH, and also in kern_exit.c:wait4()
+		 * Reparent the process so that the tracing
+		 *   proc gets to see all the action.
+		 * Stop the target.
+		 */
+		p->p_flag |= P_TRACED;
+		p->p_xstat = 0;		/* XXX ? */
+		if (p->p_pptr != curp) {
+			p->p_oppid = p->p_pptr->p_pid;
+			proc_reparent(p, curp);
+		}
+		psignal(p, SIGSTOP);
+		return (0);
+	}
+
+	/*
+	 * Target process must be stopped, owned by (curp) and
+	 * be set up for tracing (P_TRACED flag set).
+	 * Allow DETACH to take place at any time for sanity.
+	 * Allow WAIT any time, of course.
+	 */
+	switch (op) {
+	case PROCFS_CTL_DETACH:
+	case PROCFS_CTL_WAIT:
+		break;
+
+	default:
+		if (!TRACE_WAIT_P(curp, p))
+			return (EBUSY);
+	}
+
+	/*
+	 * do single-step fixup if needed
+	 */
+	FIX_SSTEP(p);
+
+	/*
+	 * Don't deliver any signal by default.
+	 * To continue with a signal, just send
+	 * the signal name to the ctl file
+	 */
+	p->p_xstat = 0;
+
+	switch (op) {
+	/*
+	 * Detach.  Cleans up the target process, reparent it if possible
+	 * and set it running once more.
+	 */
+	case PROCFS_CTL_DETACH:
+		/* if not being traced, then this is a painless no-op */
+		if ((p->p_flag & P_TRACED) == 0)
+			return (0);
+
+		/* not being traced any more */
+		p->p_flag &= ~P_TRACED;
+
+		/* give process back to original parent */
+		if (p->p_oppid != p->p_pptr->p_pid) {
+			struct proc *pp;
+
+			pp = pfind(p->p_oppid);
+			if (pp)
+				proc_reparent(p, pp);
+		}
+
+		p->p_oppid = 0;
+		p->p_flag &= ~P_WAITED;	/* XXX ? */
+		wakeup((caddr_t) curp);	/* XXX for CTL_WAIT below ? */
+
+		break;
+
+	/*
+	 * Step.  Let the target process execute a single instruction.
+	 */
+	case PROCFS_CTL_STEP:
+		procfs_sstep(p);
+		break;
+
+	/*
+	 * Run.  Let the target process continue running until a breakpoint
+	 * or some other trap.
+	 */
+	case PROCFS_CTL_RUN:
+		break;
+
+	/*
+	 * Wait for the target process to stop.
+	 * If the target is not being traced then just wait
+	 * to enter
+	 */
+	case PROCFS_CTL_WAIT:
+		error = 0;
+		if (p->p_flag & P_TRACED) {
+			while (error == 0 &&
+					(p->p_stat != SSTOP) &&
+					(p->p_flag & P_TRACED) &&
+					(p->p_pptr == curp)) {
+				error = tsleep((caddr_t) p,
+						PWAIT|PCATCH, "procfsx", 0);
+			}
+			if (error == 0 && !TRACE_WAIT_P(curp, p))
+				error = EBUSY;
+		} else {
+			while (error == 0 && p->p_stat != SSTOP) {
+				error = tsleep((caddr_t) p,
+						PWAIT|PCATCH, "procfs", 0);
+			}
+		}
+		return (error);
+
+	default:
+		panic("procfs_control");
+	}
+
+	if (p->p_stat == SSTOP)
+		setrunnable(p);
+	return (0);
+}
+
+int
+procfs_doctl(curp, p, pfs, uio)
+	struct proc *curp;
+	struct pfsnode *pfs;
+	struct uio *uio;
+	struct proc *p;
+{
+	int xlen;
+	int error;
+	char msg[PROCFS_CTLLEN+1];
+	vfs_namemap_t *nm;
+
+	if (uio->uio_rw != UIO_WRITE)
+		return (EOPNOTSUPP);
+
+	xlen = PROCFS_CTLLEN;
+	error = vfs_getuserstr(uio, msg, &xlen);
+	if (error)
+		return (error);
+
+	/*
+	 * Map signal names into signal generation
+	 * or debug control.  Unknown commands and/or signals
+	 * return EOPNOTSUPP.
+	 *
+	 * Sending a signal while the process is being debugged
+	 * also has the side effect of letting the target continue
+	 * to run.  There is no way to single-step a signal delivery.
+	 */
+	error = EOPNOTSUPP;
+
+	nm = vfs_findname(ctlnames, msg, xlen);
+	if (nm) {
+		error = procfs_control(curp, p, nm->nm_val);
+	} else {
+		nm = vfs_findname(signames, msg, xlen);
+		if (nm) {
+			if (TRACE_WAIT_P(curp, p)) {
+				p->p_xstat = nm->nm_val;
+				FIX_SSTEP(p);
+				setrunnable(p);
+			} else {
+				psignal(p, nm->nm_val);
+			}
+			error = 0;
+		}
+	}
+
+	return (error);
+}
diff --git a/sys/miscfs/procfs/procfs_fpregs.c b/sys/miscfs/procfs/procfs_fpregs.c
new file mode 100644
index 0000000..6d850a6
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_fpregs.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_fpregs.c	8.1 (Berkeley) 1/27/94
+ *
+ * From:
+ *	$Id: procfs_regs.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <machine/reg.h>
+#include <miscfs/procfs/procfs.h>
+
+int
+procfs_dofpregs(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	int error;
+	struct fpreg r;
+	char *kv;
+	int kl;
+
+	kl = sizeof(r);
+	kv = (char *) &r;
+
+	kv += uio->uio_offset;
+	kl -= uio->uio_offset;
+	if (kl > uio->uio_resid)
+		kl = uio->uio_resid;
+
+	if (kl < 0)
+		error = EINVAL;
+	else
+		error = procfs_read_fpregs(p, &r);
+	if (error == 0)
+		error = uiomove(kv, kl, uio);
+	if (error == 0 && uio->uio_rw == UIO_WRITE) {
+		if (p->p_stat != SSTOP)
+			error = EBUSY;
+		else
+			error = procfs_write_fpregs(p, &r);
+	}
+
+	uio->uio_offset = 0;
+	return (error);
+}
diff --git a/sys/miscfs/procfs/procfs_mem.c b/sys/miscfs/procfs/procfs_mem.c
new file mode 100644
index 0000000..039983d
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_mem.c
@@ -0,0 +1,302 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993 Sean Eric Fagan
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry and Sean Eric Fagan.
+ *
+ * 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.
+ *
+ *	@(#)procfs_mem.c	8.4 (Berkeley) 1/21/94
+ *
+ * From:
+ *	$Id: procfs_mem.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+/*
+ * This is a lightly hacked and merged version
+ * of sef's pread/pwrite functions
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>
+#include <vm/vm_kern.h>
+#include <vm/vm_page.h>
+
+static int
+procfs_rwmem(p, uio)
+	struct proc *p;
+	struct uio *uio;
+{
+	int error;
+	int writing;
+
+	writing = uio->uio_rw == UIO_WRITE;
+
+	/*
+	 * Only map in one page at a time.  We don't have to, but it
+	 * makes things easier.  This way is trivial - right?
+	 */
+	do {
+		vm_map_t map, tmap;
+		vm_object_t object;
+		vm_offset_t kva;
+		vm_offset_t uva;
+		int page_offset;		/* offset into page */
+		vm_offset_t pageno;		/* page number */
+		vm_map_entry_t out_entry;
+		vm_prot_t out_prot;
+		vm_page_t m;
+		boolean_t wired, single_use;
+		vm_offset_t off;
+		u_int len;
+		int fix_prot;
+
+		uva = (vm_offset_t) uio->uio_offset;
+		if (uva > VM_MAXUSER_ADDRESS) {
+			error = 0;
+			break;
+		}
+
+		/*
+		 * Get the page number of this segment.
+		 */
+		pageno = trunc_page(uva);
+		page_offset = uva - pageno;
+
+		/*
+		 * How many bytes to copy
+		 */
+		len = min(PAGE_SIZE - page_offset, uio->uio_resid);
+
+		/*
+		 * The map we want...
+		 */
+		map = &p->p_vmspace->vm_map;
+  
+		/*
+		 * Check the permissions for the area we're interested
+		 * in.
+		 */
+		fix_prot = 0;
+		if (writing)
+			fix_prot = !vm_map_check_protection(map, pageno,
+					pageno + PAGE_SIZE, VM_PROT_WRITE);
+
+		if (fix_prot) {
+			/*
+			 * If the page is not writable, we make it so.
+			 * XXX It is possible that a page may *not* be
+			 * read/executable, if a process changes that!
+			 * We will assume, for now, that a page is either
+			 * VM_PROT_ALL, or VM_PROT_READ|VM_PROT_EXECUTE.
+			 */
+			error = vm_map_protect(map, pageno,
+					pageno + PAGE_SIZE, VM_PROT_ALL, 0);
+			if (error)
+				break;
+		}
+
+		/*
+		 * Now we need to get the page.  out_entry, out_prot, wired,
+		 * and single_use aren't used.  One would think the vm code
+		 * would be a *bit* nicer...  We use tmap because
+		 * vm_map_lookup() can change the map argument.
+		 */
+		tmap = map;
+		error = vm_map_lookup(&tmap, pageno,
+				      writing ? VM_PROT_WRITE : VM_PROT_READ,
+				      &out_entry, &object, &off, &out_prot,
+				      &wired, &single_use);
+		/*
+		 * We're done with tmap now.
+		 */
+		if (!error)
+			vm_map_lookup_done(tmap, out_entry);
+  
+		/*
+		 * Fault the page in...
+		 */
+		if (!error && writing && object->shadow) {
+			m = vm_page_lookup(object, off);
+			if (m == 0 || (m->flags & PG_COPYONWRITE))
+				error = vm_fault(map, pageno,
+							VM_PROT_WRITE, FALSE);
+		}
+
+		/* Find space in kernel_map for the page we're interested in */
+		if (!error)
+			error = vm_map_find(kernel_map, object, off, &kva,
+					PAGE_SIZE, 1);
+
+		if (!error) {
+			/*
+			 * Neither vm_map_lookup() nor vm_map_find() appear
+			 * to add a reference count to the object, so we do
+			 * that here and now.
+			 */
+			vm_object_reference(object);
+
+			/*
+			 * Mark the page we just found as pageable.
+			 */
+			error = vm_map_pageable(kernel_map, kva,
+				kva + PAGE_SIZE, 0);
+
+			/*
+			 * Now do the i/o move.
+			 */
+			if (!error)
+				error = uiomove(kva + page_offset, len, uio);
+
+			vm_map_remove(kernel_map, kva, kva + PAGE_SIZE);
+		}
+		if (fix_prot)
+			vm_map_protect(map, pageno, pageno + PAGE_SIZE,
+					VM_PROT_READ|VM_PROT_EXECUTE, 0);
+	} while (error == 0 && uio->uio_resid > 0);
+
+	return (error);
+}
+
+/*
+ * Copy data in and out of the target process.
+ * We do this by mapping the process's page into
+ * the kernel and then doing a uiomove direct
+ * from the kernel address space.
+ */
+int
+procfs_domem(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	int error;
+
+	if (uio->uio_resid == 0)
+		return (0);
+
+	error = procfs_rwmem(p, uio);
+
+	return (error);
+}
+
+/*
+ * Given process (p), find the vnode from which
+ * it's text segment is being executed.
+ *
+ * It would be nice to grab this information from
+ * the VM system, however, there is no sure-fire
+ * way of doing that.  Instead, fork(), exec() and
+ * wait() all maintain the p_textvp field in the
+ * process proc structure which contains a held
+ * reference to the exec'ed vnode.
+ */
+struct vnode *
+procfs_findtextvp(p)
+	struct proc *p;
+{
+	return (p->p_textvp);
+}
+
+
+#ifdef probably_never
+/*
+ * Given process (p), find the vnode from which
+ * it's text segment is being mapped.
+ *
+ * (This is here, rather than in procfs_subr in order
+ * to keep all the VM related code in one place.)
+ */
+struct vnode *
+procfs_findtextvp(p)
+	struct proc *p;
+{
+	int error;
+	vm_object_t object;
+	vm_offset_t pageno;		/* page number */
+
+	/* find a vnode pager for the user address space */
+
+	for (pageno = VM_MIN_ADDRESS;
+			pageno < VM_MAXUSER_ADDRESS;
+			pageno += PAGE_SIZE) {
+		vm_map_t map;
+		vm_map_entry_t out_entry;
+		vm_prot_t out_prot;
+		boolean_t wired, single_use;
+		vm_offset_t off;
+
+		map = &p->p_vmspace->vm_map;
+		error = vm_map_lookup(&map, pageno,
+			      VM_PROT_READ,
+			      &out_entry, &object, &off, &out_prot,
+			      &wired, &single_use);
+
+		if (!error) {
+			vm_pager_t pager;
+
+			printf("procfs: found vm object\n");
+			vm_map_lookup_done(map, out_entry);
+			printf("procfs: vm object = %x\n", object);
+
+			/*
+			 * At this point, assuming no errors, object
+			 * is the VM object mapping UVA (pageno).
+			 * Ensure it has a vnode pager, then grab
+			 * the vnode from that pager's handle.
+			 */
+
+			pager = object->pager;
+			printf("procfs: pager = %x\n", pager);
+			if (pager)
+				printf("procfs: found pager, type = %d\n", pager->pg_type);
+			if (pager && pager->pg_type == PG_VNODE) {
+				struct vnode *vp;
+
+				vp = (struct vnode *) pager->pg_handle;
+				printf("procfs: vp = 0x%x\n", vp);
+				return (vp);
+			}
+		}
+	}
+
+	printf("procfs: text object not found\n");
+	return (0);
+}
+#endif /* probably_never */
diff --git a/sys/miscfs/procfs/procfs_note.c b/sys/miscfs/procfs/procfs_note.c
new file mode 100644
index 0000000..bf2f160
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_note.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_note.c	8.2 (Berkeley) 1/21/94
+ *
+ * From:
+ *	$Id: procfs_note.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/signal.h>
+#include <miscfs/procfs/procfs.h>
+
+int
+procfs_donote(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	int xlen;
+	int error;
+	char note[PROCFS_NOTELEN+1];
+
+	if (uio->uio_rw != UIO_WRITE)
+		return (EINVAL);
+
+	xlen = PROCFS_NOTELEN;
+	error = vfs_getuserstr(uio, note, &xlen);
+	if (error)
+		return (error);
+
+	/* send to process's notify function */
+	return (EOPNOTSUPP);
+}
diff --git a/sys/miscfs/procfs/procfs_regs.c b/sys/miscfs/procfs/procfs_regs.c
new file mode 100644
index 0000000..fa95fef
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_regs.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_regs.c	8.3 (Berkeley) 1/27/94
+ *
+ * From:
+ *	$Id: procfs_regs.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <machine/reg.h>
+#include <miscfs/procfs/procfs.h>
+
+int
+procfs_doregs(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	int error;
+	struct reg r;
+	char *kv;
+	int kl;
+
+	kl = sizeof(r);
+	kv = (char *) &r;
+
+	kv += uio->uio_offset;
+	kl -= uio->uio_offset;
+	if (kl > uio->uio_resid)
+		kl = uio->uio_resid;
+
+	if (kl < 0)
+		error = EINVAL;
+	else
+		error = procfs_read_regs(p, &r);
+	if (error == 0)
+		error = uiomove(kv, kl, uio);
+	if (error == 0 && uio->uio_rw == UIO_WRITE) {
+		if (p->p_stat != SSTOP)
+			error = EBUSY;
+		else
+			error = procfs_write_regs(p, &r);
+	}
+
+	uio->uio_offset = 0;
+	return (error);
+}
diff --git a/sys/miscfs/procfs/procfs_status.c b/sys/miscfs/procfs/procfs_status.c
new file mode 100644
index 0000000..d88aaab
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_status.c
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_status.c	8.3 (Berkeley) 2/17/94
+ *
+ * From:
+ *	$Id: procfs_status.c,v 3.1 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/ioctl.h>
+#include <sys/tty.h>
+#include <sys/resource.h>
+#include <sys/resourcevar.h>
+#include <miscfs/procfs/procfs.h>
+
+int
+procfs_dostatus(curp, p, pfs, uio)
+	struct proc *curp;
+	struct proc *p;
+	struct pfsnode *pfs;
+	struct uio *uio;
+{
+	struct session *sess;
+	struct tty *tp;
+	struct ucred *cr;
+	char *ps;
+	char *sep;
+	int pid, ppid, pgid, sid;
+	int i;
+	int xlen;
+	int error;
+	char psbuf[256];		/* XXX - conservative */
+
+	if (uio->uio_rw != UIO_READ)
+		return (EOPNOTSUPP);
+
+	pid = p->p_pid;
+	ppid = p->p_pptr ? p->p_pptr->p_pid : 0,
+	pgid = p->p_pgrp->pg_id;
+	sess = p->p_pgrp->pg_session;
+	sid = sess->s_leader ? sess->s_leader->p_pid : 0;
+
+/* comm pid ppid pgid sid maj,min ctty,sldr start ut st wmsg uid groups ... */
+
+	ps = psbuf;
+	bcopy(p->p_comm, ps, MAXCOMLEN);
+	ps[MAXCOMLEN] = '\0';
+	ps += strlen(ps);
+	ps += sprintf(ps, " %d %d %d %d ", pid, ppid, pgid, sid);
+
+	if ((p->p_flag&P_CONTROLT) && (tp = sess->s_ttyp))
+		ps += sprintf(ps, "%d,%d ", major(tp->t_dev), minor(tp->t_dev));
+	else
+		ps += sprintf(ps, "%d,%d ", -1, -1);
+
+	sep = "";
+	if (sess->s_ttyvp) {
+		ps += sprintf(ps, "%sctty", sep);
+		sep = ",";
+	}
+	if (SESS_LEADER(p)) {
+		ps += sprintf(ps, "%ssldr", sep);
+		sep = ",";
+	}
+	if (*sep != ',')
+		ps += sprintf(ps, "noflags");
+
+	if (p->p_flag & P_INMEM)
+		ps += sprintf(ps, " %d,%d",
+			p->p_stats->p_start.tv_sec,
+			p->p_stats->p_start.tv_usec);
+	else
+		ps += sprintf(ps, " -1,-1");
+	
+	{
+		struct timeval ut, st;
+
+		calcru(p, &ut, &st, (void *) 0);
+		ps += sprintf(ps, " %d,%d %d,%d",
+			ut.tv_sec,
+			ut.tv_usec,
+			st.tv_sec,
+			st.tv_usec);
+	}
+
+	ps += sprintf(ps, " %s",
+		(p->p_wchan && p->p_wmesg) ? p->p_wmesg : "nochan");
+
+	cr = p->p_ucred;
+
+	ps += sprintf(ps, " %d", cr->cr_uid, cr->cr_gid);
+	for (i = 0; i < cr->cr_ngroups; i++)
+		ps += sprintf(ps, ",%d", cr->cr_groups[i]);
+	ps += sprintf(ps, "\n");
+
+	xlen = ps - psbuf;
+	xlen -= uio->uio_offset;
+	ps = psbuf + uio->uio_offset;
+	xlen = min(xlen, uio->uio_resid);
+	if (xlen <= 0)
+		error = 0;
+	else
+		error = uiomove(ps, xlen, uio);
+
+	return (error);
+}
diff --git a/sys/miscfs/procfs/procfs_subr.c b/sys/miscfs/procfs/procfs_subr.c
new file mode 100644
index 0000000..b371af1
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_subr.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_subr.c	8.4 (Berkeley) 1/27/94
+ *
+ * From:
+ *	$Id: procfs_subr.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/malloc.h>
+#include <miscfs/procfs/procfs.h>
+
+static struct pfsnode *pfshead;
+static int pfsvplock;
+
+/*
+ * allocate a pfsnode/vnode pair.  the vnode is
+ * referenced, but not locked.
+ *
+ * the pid, pfs_type, and mount point uniquely
+ * identify a pfsnode.  the mount point is needed
+ * because someone might mount this filesystem
+ * twice.
+ *
+ * all pfsnodes are maintained on a singly-linked
+ * list.  new nodes are only allocated when they cannot
+ * be found on this list.  entries on the list are
+ * removed when the vfs reclaim entry is called.
+ *
+ * a single lock is kept for the entire list.  this is
+ * needed because the getnewvnode() function can block
+ * waiting for a vnode to become free, in which case there
+ * may be more than one process trying to get the same
+ * vnode.  this lock is only taken if we are going to
+ * call getnewvnode, since the kernel itself is single-threaded.
+ *
+ * if an entry is found on the list, then call vget() to
+ * take a reference.  this is done because there may be
+ * zero references to it and so it needs to removed from
+ * the vnode free list.
+ */
+int
+procfs_allocvp(mp, vpp, pid, pfs_type)
+	struct mount *mp;
+	struct vnode **vpp;
+	long pid;
+	pfstype pfs_type;
+{
+	int error;
+	struct pfsnode *pfs;
+	struct pfsnode **pp;
+
+loop:
+	for (pfs = pfshead; pfs != 0; pfs = pfs->pfs_next) {
+		if (pfs->pfs_pid == pid &&
+		    pfs->pfs_type == pfs_type &&
+		    PFSTOV(pfs)->v_mount == mp) {
+			if (vget(pfs->pfs_vnode, 0))
+				goto loop;
+			*vpp = pfs->pfs_vnode;
+			return (0);
+		}
+	}
+
+	/*
+	 * otherwise lock the vp list while we call getnewvnode
+	 * since that can block.
+	 */ 
+	if (pfsvplock & PROCFS_LOCKED) {
+		pfsvplock |= PROCFS_WANT;
+		sleep((caddr_t) &pfsvplock, PINOD);
+		goto loop;
+	}
+	pfsvplock |= PROCFS_LOCKED;
+
+	error = getnewvnode(VT_PROCFS, mp, procfs_vnodeop_p, vpp);
+	if (error)
+		goto out;
+
+	MALLOC((*vpp)->v_data, void *, sizeof(struct pfsnode),
+		M_TEMP, M_WAITOK);
+
+	pfs = VTOPFS(*vpp);
+	pfs->pfs_next = 0;
+	pfs->pfs_pid = (pid_t) pid;
+	pfs->pfs_type = pfs_type;
+	pfs->pfs_vnode = *vpp;
+	pfs->pfs_flags = 0;
+	pfs->pfs_fileno = PROCFS_FILENO(pid, pfs_type);
+
+	switch (pfs_type) {
+	case Proot:	/* /proc = dr-xr-xr-x */
+		pfs->pfs_mode = (VREAD|VEXEC) |
+				(VREAD|VEXEC) >> 3 |
+				(VREAD|VEXEC) >> 6;
+		break;
+
+	case Pproc:
+		pfs->pfs_mode = (VREAD|VEXEC) |
+				(VREAD|VEXEC) >> 3 |
+				(VREAD|VEXEC) >> 6;
+		break;
+
+	case Pfile:
+		pfs->pfs_mode = (VREAD|VWRITE);
+		break;
+
+	case Pmem:
+		pfs->pfs_mode = (VREAD|VWRITE);
+		break;
+
+	case Pregs:
+		pfs->pfs_mode = (VREAD|VWRITE);
+		break;
+
+	case Pfpregs:
+		pfs->pfs_mode = (VREAD|VWRITE);
+		break;
+
+	case Pctl:
+		pfs->pfs_mode = (VWRITE);
+		break;
+
+	case Pstatus:
+		pfs->pfs_mode = (VREAD) |
+				(VREAD >> 3) |
+				(VREAD >> 6);
+		break;
+
+	case Pnote:
+		pfs->pfs_mode = (VWRITE);
+		break;
+
+	case Pnotepg:
+		pfs->pfs_mode = (VWRITE);
+		break;
+
+	default:
+		panic("procfs_allocvp");
+	}
+
+	/* add to procfs vnode list */
+	for (pp = &pfshead; *pp; pp = &(*pp)->pfs_next)
+		continue;
+	*pp = pfs;
+
+out:
+	pfsvplock &= ~PROCFS_LOCKED;
+
+	if (pfsvplock & PROCFS_WANT) {
+		pfsvplock &= ~PROCFS_WANT;
+		wakeup((caddr_t) &pfsvplock);
+	}
+
+	return (error);
+}
+
+int
+procfs_freevp(vp)
+	struct vnode *vp;
+{
+	struct pfsnode **pfspp;
+	struct pfsnode *pfs = VTOPFS(vp);
+
+	for (pfspp = &pfshead; *pfspp != 0; pfspp = &(*pfspp)->pfs_next) {
+		if (*pfspp == pfs) {
+			*pfspp = pfs->pfs_next;
+			break;
+		}
+	}
+
+	FREE(vp->v_data, M_TEMP);
+	vp->v_data = 0;
+	return (0);
+}
+
+int
+procfs_rw(ap)
+	struct vop_read_args *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct uio *uio = ap->a_uio;
+	struct proc *curp = uio->uio_procp;
+	struct pfsnode *pfs = VTOPFS(vp);
+	struct proc *p;
+
+	p = PFIND(pfs->pfs_pid);
+	if (p == 0)
+		return (EINVAL);
+
+	switch (pfs->pfs_type) {
+	case Pnote:
+	case Pnotepg:
+		return (procfs_donote(curp, p, pfs, uio));
+
+	case Pregs:
+		return (procfs_doregs(curp, p, pfs, uio));
+
+	case Pfpregs:
+		return (procfs_dofpregs(curp, p, pfs, uio));
+
+	case Pctl:
+		return (procfs_doctl(curp, p, pfs, uio));
+
+	case Pstatus:
+		return (procfs_dostatus(curp, p, pfs, uio));
+
+	case Pmem:
+		return (procfs_domem(curp, p, pfs, uio));
+
+	default:
+		return (EOPNOTSUPP);
+	}
+}
+
+/*
+ * Get a string from userland into (buf).  Strip a trailing
+ * nl character (to allow easy access from the shell).
+ * The buffer should be *buflenp + 1 chars long.  vfs_getuserstr
+ * will automatically add a nul char at the end.
+ *
+ * Returns 0 on success or the following errors
+ *
+ * EINVAL:    file offset is non-zero.
+ * EMSGSIZE:  message is longer than kernel buffer
+ * EFAULT:    user i/o buffer is not addressable
+ */
+int
+vfs_getuserstr(uio, buf, buflenp)
+	struct uio *uio;
+	char *buf;
+	int *buflenp;
+{
+	int xlen;
+	int error;
+
+	if (uio->uio_offset != 0)
+		return (EINVAL);
+
+	xlen = *buflenp;
+
+	/* must be able to read the whole string in one go */
+	if (xlen < uio->uio_resid)
+		return (EMSGSIZE);
+	xlen = uio->uio_resid;
+
+	error = uiomove(buf, xlen, uio);
+	if (error)
+		return (error);
+
+	/* allow multiple writes without seeks */
+	uio->uio_offset = 0;
+
+	/* cleanup string and remove trailing newline */
+	buf[xlen] = '\0';
+	xlen = strlen(buf);
+	if (xlen > 0 && buf[xlen-1] == '\n')
+		buf[--xlen] = '\0';
+	*buflenp = xlen;
+
+	return (0);
+}
+
+vfs_namemap_t *
+vfs_findname(nm, buf, buflen)
+	vfs_namemap_t *nm;
+	char *buf;
+	int buflen;
+{
+	for (; nm->nm_name; nm++)
+		if (bcmp(buf, (char *) nm->nm_name, buflen+1) == 0)
+			return (nm);
+
+	return (0);
+}
diff --git a/sys/miscfs/procfs/procfs_vfsops.c b/sys/miscfs/procfs/procfs_vfsops.c
new file mode 100644
index 0000000..3938ca1
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_vfsops.c
@@ -0,0 +1,243 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_vfsops.c	8.4 (Berkeley) 1/21/94
+ *
+ * From:
+ *	$Id: procfs_vfsops.c,v 3.1 1993/12/15 09:40:17 jsp Exp $
+ */
+
+/*
+ * procfs VFS interface
+ */
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/proc.h>
+#include <sys/buf.h>
+#include <sys/syslog.h>
+#include <sys/mount.h>
+#include <sys/signalvar.h>
+#include <sys/vnode.h>
+#include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>			/* for PAGE_SIZE */
+
+/*
+ * VFS Operations.
+ *
+ * mount system call
+ */
+/* ARGSUSED */
+procfs_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	u_int size;
+
+	if (UIO_MX & (UIO_MX-1)) {
+		log(LOG_ERR, "procfs: invalid directory entry size");
+		return (EINVAL);
+	}
+
+	if (mp->mnt_flag & MNT_UPDATE)
+		return (EOPNOTSUPP);
+
+	mp->mnt_flag |= MNT_LOCAL;
+	mp->mnt_data = 0;
+	getnewfsid(mp, MOUNT_PROCFS);
+
+	(void) copyinstr(path, (caddr_t)mp->mnt_stat.f_mntonname, MNAMELEN, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+
+	size = sizeof("procfs") - 1;
+	bcopy("procfs", mp->mnt_stat.f_mntfromname, size);
+	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
+
+	return (0);
+}
+
+/*
+ * unmount system call
+ */
+procfs_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	int error;
+	extern int doforce;
+	int flags = 0;
+
+	if (mntflags & MNT_FORCE) {
+		/* procfs can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	if (error = vflush(mp, 0, flags))
+		return (error);
+
+	return (0);
+}
+
+procfs_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct pfsnode *pfs;
+	struct vnode *vp;
+	int error;
+
+	error = procfs_allocvp(mp, &vp, (pid_t) 0, Proot);
+	if (error)
+		return (error);
+
+	vp->v_type = VDIR;
+	vp->v_flag = VROOT;
+	pfs = VTOPFS(vp);
+
+	*vpp = vp;
+	return (0);
+}
+
+/*
+ */
+/* ARGSUSED */
+procfs_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+
+	return (0);
+}
+
+/*
+ * Get file system statistics.
+ */
+procfs_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+	sbp->f_type = MOUNT_PROCFS;
+	sbp->f_bsize = PAGE_SIZE;
+	sbp->f_iosize = PAGE_SIZE;
+	sbp->f_blocks = 1;	/* avoid divide by zero in some df's */
+	sbp->f_bfree = 0;
+	sbp->f_bavail = 0;
+	sbp->f_files = maxproc;			/* approx */
+	sbp->f_ffree = maxproc - nprocs;	/* approx */
+
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+
+	return (0);
+}
+
+
+procfs_quotactl(mp, cmds, uid, arg, p)
+	struct mount *mp;
+	int cmds;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+
+	return (EOPNOTSUPP);
+}
+
+procfs_sync(mp, waitfor)
+	struct mount *mp;
+	int waitfor;
+{
+
+	return (0);
+}
+
+procfs_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+procfs_fhtovp(mp, fhp, vpp)
+	struct mount *mp;
+	struct fid *fhp;
+	struct vnode **vpp;
+{
+
+	return (EINVAL);
+}
+
+procfs_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+
+	return EINVAL;
+}
+
+procfs_init()
+{
+
+	return (0);
+}
+
+struct vfsops procfs_vfsops = {
+	procfs_mount,
+	procfs_start,
+	procfs_unmount,
+	procfs_root,
+	procfs_quotactl,
+	procfs_statfs,
+	procfs_sync,
+	procfs_vget,
+	procfs_fhtovp,
+	procfs_vptofh,
+	procfs_init,
+};
diff --git a/sys/miscfs/procfs/procfs_vnops.c b/sys/miscfs/procfs/procfs_vnops.c
new file mode 100644
index 0000000..4e1ee00
--- /dev/null
+++ b/sys/miscfs/procfs/procfs_vnops.c
@@ -0,0 +1,814 @@
+/*
+ * Copyright (c) 1993 Jan-Simon Pendry
+ * Copyright (c) 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)procfs_vnops.c	8.6 (Berkeley) 2/7/94
+ *
+ * From:
+ *	$Id: procfs_vnops.c,v 3.2 1993/12/15 09:40:17 jsp Exp $
+ */
+
+/*
+ * procfs vnode interface
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/file.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/dirent.h>
+#include <sys/resourcevar.h>
+#include <miscfs/procfs/procfs.h>
+#include <vm/vm.h>	/* for PAGE_SIZE */
+
+/*
+ * Vnode Operations.
+ *
+ */
+
+/*
+ * This is a list of the valid names in the
+ * process-specific sub-directories.  It is
+ * used in procfs_lookup and procfs_readdir
+ */
+static struct pfsnames {
+	u_short	d_namlen;
+	char	d_name[PROCFS_NAMELEN];
+	pfstype	d_pfstype;
+} procent[] = {
+#define N(s) sizeof(s)-1, s
+	/* namlen, nam, type */
+	{  N("file"),	Pfile },
+	{  N("mem"),	Pmem },
+	{  N("regs"),	Pregs },
+	{  N("fpregs"),	Pfpregs },
+	{  N("ctl"),	Pctl },
+	{  N("status"),	Pstatus },
+	{  N("note"),	Pnote },
+	{  N("notepg"),	Pnotepg },
+#undef N
+};
+#define Nprocent (sizeof(procent)/sizeof(procent[0]))
+
+static pid_t atopid __P((const char *, u_int));
+
+/*
+ * set things up for doing i/o on
+ * the pfsnode (vp).  (vp) is locked
+ * on entry, and should be left locked
+ * on exit.
+ *
+ * for procfs we don't need to do anything
+ * in particular for i/o.  all that is done
+ * is to support exclusive open on process
+ * memory images.
+ */
+procfs_open(ap)
+	struct vop_open_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+
+	switch (pfs->pfs_type) {
+	case Pmem:
+		if (PFIND(pfs->pfs_pid) == 0)
+			return (ENOENT);	/* was ESRCH, jsp */
+
+		if ((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL) ||
+				(pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))
+			return (EBUSY);
+
+
+		if (ap->a_mode & FWRITE)
+			pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL);
+
+		return (0);
+
+	default:
+		break;
+	}
+
+	return (0);
+}
+
+/*
+ * close the pfsnode (vp) after doing i/o.
+ * (vp) is not locked on entry or exit.
+ *
+ * nothing to do for procfs other than undo
+ * any exclusive open flag (see _open above).
+ */
+procfs_close(ap)
+	struct vop_close_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+
+	switch (pfs->pfs_type) {
+	case Pmem:
+		if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL))
+			pfs->pfs_flags &= ~(FWRITE|O_EXCL);
+		break;
+	}
+
+	return (0);
+}
+
+/*
+ * do an ioctl operation on pfsnode (vp).
+ * (vp) is not locked on entry or exit.
+ */
+procfs_ioctl(ap)
+	struct vop_ioctl_args *ap;
+{
+
+	return (ENOTTY);
+}
+
+/*
+ * do block mapping for pfsnode (vp).
+ * since we don't use the buffer cache
+ * for procfs this function should never
+ * be called.  in any case, it's not clear
+ * what part of the kernel ever makes use
+ * of this function.  for sanity, this is the
+ * usual no-op bmap, although returning
+ * (EIO) would be a reasonable alternative.
+ */
+procfs_bmap(ap)
+	struct vop_bmap_args *ap;
+{
+
+	if (ap->a_vpp != NULL)
+		*ap->a_vpp = ap->a_vp;
+	if (ap->a_bnp != NULL)
+		*ap->a_bnp = ap->a_bn;
+	return (0);
+}
+
+/*
+ * _inactive is called when the pfsnode
+ * is vrele'd and the reference count goes
+ * to zero.  (vp) will be on the vnode free
+ * list, so to get it back vget() must be
+ * used.
+ *
+ * for procfs, check if the process is still
+ * alive and if it isn't then just throw away
+ * the vnode by calling vgone().  this may
+ * be overkill and a waste of time since the
+ * chances are that the process will still be
+ * there and PFIND is not free.
+ *
+ * (vp) is not locked on entry or exit.
+ */
+procfs_inactive(ap)
+	struct vop_inactive_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+
+	if (PFIND(pfs->pfs_pid) == 0)
+		vgone(ap->a_vp);
+
+	return (0);
+}
+
+/*
+ * _reclaim is called when getnewvnode()
+ * wants to make use of an entry on the vnode
+ * free list.  at this time the filesystem needs
+ * to free any private data and remove the node
+ * from any private lists.
+ */
+procfs_reclaim(ap)
+	struct vop_reclaim_args *ap;
+{
+	int error;
+
+	error = procfs_freevp(ap->a_vp);
+	return (error);
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+procfs_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_MAX_CANON:
+		*ap->a_retval = MAX_CANON;
+		return (0);
+	case _PC_MAX_INPUT:
+		*ap->a_retval = MAX_INPUT;
+		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_VDISABLE:
+		*ap->a_retval = _POSIX_VDISABLE;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * _print is used for debugging.
+ * just print a readable description
+ * of (vp).
+ */
+procfs_print(ap)
+	struct vop_print_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+
+	printf("tag VT_PROCFS, pid %d, mode %x, flags %x\n",
+		pfs->pfs_pid,
+		pfs->pfs_mode, pfs->pfs_flags);
+}
+
+/*
+ * _abortop is called when operations such as
+ * rename and create fail.  this entry is responsible
+ * for undoing any side-effects caused by the lookup.
+ * this will always include freeing the pathname buffer.
+ */
+procfs_abortop(ap)
+	struct vop_abortop_args *ap;
+{
+
+	if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
+		FREE(ap->a_cnp->cn_pnbuf, M_NAMEI);
+	return (0);
+}
+
+/*
+ * generic entry point for unsupported operations
+ */
+procfs_badop()
+{
+
+	return (EIO);
+}
+
+/*
+ * Invent attributes for pfsnode (vp) and store
+ * them in (vap).
+ * Directories lengths are returned as zero since
+ * any real length would require the genuine size
+ * to be computed, and nothing cares anyway.
+ *
+ * this is relatively minimal for procfs.
+ */
+procfs_getattr(ap)
+	struct vop_getattr_args *ap;
+{
+	struct pfsnode *pfs = VTOPFS(ap->a_vp);
+	struct vattr *vap = ap->a_vap;
+	struct proc *procp;
+	int error;
+
+	/* first check the process still exists */
+	switch (pfs->pfs_type) {
+	case Proot:
+		procp = 0;
+		break;
+
+	default:
+		procp = PFIND(pfs->pfs_pid);
+		if (procp == 0)
+			return (ENOENT);
+	}
+
+	error = 0;
+
+	/* start by zeroing out the attributes */
+	VATTR_NULL(vap);
+
+	/* next do all the common fields */
+	vap->va_type = ap->a_vp->v_type;
+	vap->va_mode = pfs->pfs_mode;
+	vap->va_fileid = pfs->pfs_fileno;
+	vap->va_flags = 0;
+	vap->va_blocksize = PAGE_SIZE;
+	vap->va_bytes = vap->va_size = 0;
+
+	/*
+	 * If the process has exercised some setuid or setgid
+	 * privilege, then rip away read/write permission so
+	 * that only root can gain access.
+	 */
+	switch (pfs->pfs_type) {
+	case Pregs:
+	case Pfpregs:
+	case Pmem:
+		if (procp->p_flag & P_SUGID)
+			vap->va_mode &= ~((VREAD|VWRITE)|
+					  ((VREAD|VWRITE)>>3)|
+					  ((VREAD|VWRITE)>>6));
+		break;
+	}
+
+	/*
+	 * Make all times be current TOD.
+	 * It would be possible to get the process start
+	 * time from the p_stat structure, but there's
+	 * no "file creation" time stamp anyway, and the
+	 * p_stat structure is not addressible if u. gets
+	 * swapped out for that process.
+	 */
+	microtime(&vap->va_ctime);
+	vap->va_atime = vap->va_mtime = vap->va_ctime;
+
+	/*
+	 * now do the object specific fields
+	 *
+	 * The size could be set from struct reg, but it's hardly
+	 * worth the trouble, and it puts some (potentially) machine
+	 * dependent data into this machine-independent code.  If it
+	 * becomes important then this function should break out into
+	 * a per-file stat function in the corresponding .c file.
+	 */
+
+	switch (pfs->pfs_type) {
+	case Proot:
+		vap->va_nlink = 2;
+		vap->va_uid = 0;
+		vap->va_gid = 0;
+		break;
+
+	case Pproc:
+		vap->va_nlink = 2;
+		vap->va_uid = procp->p_ucred->cr_uid;
+		vap->va_gid = procp->p_ucred->cr_gid;
+		break;
+
+	case Pfile:
+		error = EOPNOTSUPP;
+		break;
+
+	case Pmem:
+		vap->va_nlink = 1;
+		vap->va_bytes = vap->va_size =
+			ctob(procp->p_vmspace->vm_tsize +
+				    procp->p_vmspace->vm_dsize +
+				    procp->p_vmspace->vm_ssize);
+		vap->va_uid = procp->p_ucred->cr_uid;
+		vap->va_gid = procp->p_ucred->cr_gid;
+		break;
+
+	case Pregs:
+	case Pfpregs:
+	case Pctl:
+	case Pstatus:
+	case Pnote:
+	case Pnotepg:
+		vap->va_nlink = 1;
+		vap->va_uid = procp->p_ucred->cr_uid;
+		vap->va_gid = procp->p_ucred->cr_gid;
+		break;
+
+	default:
+		panic("procfs_getattr");
+	}
+
+	return (error);
+}
+
+procfs_setattr(ap)
+	struct vop_setattr_args *ap;
+{
+	/*
+	 * just fake out attribute setting
+	 * it's not good to generate an error
+	 * return, otherwise things like creat()
+	 * will fail when they try to set the
+	 * file length to 0.  worse, this means
+	 * that echo $note > /proc/$pid/note will fail.
+	 */
+
+	return (0);
+}
+
+/*
+ * implement access checking.
+ *
+ * something very similar to this code is duplicated
+ * throughout the 4bsd kernel and should be moved
+ * into kern/vfs_subr.c sometime.
+ *
+ * actually, the check for super-user is slightly
+ * broken since it will allow read access to write-only
+ * objects.  this doesn't cause any particular trouble
+ * but does mean that the i/o entry points need to check
+ * that the operation really does make sense.
+ */
+procfs_access(ap)
+	struct vop_access_args *ap;
+{
+	struct vattr *vap;
+	struct vattr vattr;
+	int error;
+
+	/*
+	 * If you're the super-user,
+	 * you always get access.
+	 */
+	if (ap->a_cred->cr_uid == (uid_t) 0)
+		return (0);
+	vap = &vattr;
+	if (error = VOP_GETATTR(ap->a_vp, vap, ap->a_cred, ap->a_p))
+		return (error);
+
+	/*
+	 * Access check is based on only one of owner, group, public.
+	 * If not owner, then check group. If not a member of the
+	 * group, then check public access.
+	 */
+	if (ap->a_cred->cr_uid != vap->va_uid) {
+		gid_t *gp;
+		int i;
+
+		(ap->a_mode) >>= 3;
+		gp = ap->a_cred->cr_groups;
+		for (i = 0; i < ap->a_cred->cr_ngroups; i++, gp++)
+			if (vap->va_gid == *gp)
+				goto found;
+		ap->a_mode >>= 3;
+found:
+		;
+	}
+
+	if ((vap->va_mode & ap->a_mode) == ap->a_mode)
+		return (0);
+
+	return (EACCES);
+}
+
+/*
+ * lookup.  this is incredibly complicated in the
+ * general case, however for most pseudo-filesystems
+ * very little needs to be done.
+ *
+ * unless you want to get a migraine, just make sure your
+ * filesystem doesn't do any locking of its own.  otherwise
+ * read and inwardly digest ufs_lookup().
+ */
+procfs_lookup(ap)
+	struct vop_lookup_args *ap;
+{
+	struct componentname *cnp = ap->a_cnp;
+	struct vnode **vpp = ap->a_vpp;
+	struct vnode *dvp = ap->a_dvp;
+	char *pname = cnp->cn_nameptr;
+	int error = 0;
+	pid_t pid;
+	struct vnode *nvp;
+	struct pfsnode *pfs;
+	struct proc *procp;
+	pfstype pfs_type;
+	int i;
+
+	if (cnp->cn_namelen == 1 && *pname == '.') {
+		*vpp = dvp;
+		VREF(dvp);
+		/*VOP_LOCK(dvp);*/
+		return (0);
+	}
+
+	*vpp = NULL;
+
+	pfs = VTOPFS(dvp);
+	switch (pfs->pfs_type) {
+	case Proot:
+		if (cnp->cn_flags & ISDOTDOT)
+			return (EIO);
+
+		if (CNEQ(cnp, "curproc", 7))
+			pid = cnp->cn_proc->p_pid;
+		else
+			pid = atopid(pname, cnp->cn_namelen);
+		if (pid == NO_PID)
+			return (ENOENT);
+
+		procp = PFIND(pid);
+		if (procp == 0)
+			return (ENOENT);
+
+		error = procfs_allocvp(dvp->v_mount, &nvp, pid, Pproc);
+		if (error)
+			return (error);
+
+		nvp->v_type = VDIR;
+		pfs = VTOPFS(nvp);
+
+		*vpp = nvp;
+		return (0);
+
+	case Pproc:
+		if (cnp->cn_flags & ISDOTDOT) {
+			error = procfs_root(dvp->v_mount, vpp);
+			return (error);
+		}
+
+		procp = PFIND(pfs->pfs_pid);
+		if (procp == 0)
+			return (ENOENT);
+
+		for (i = 0; i < Nprocent; i++) {
+			struct pfsnames *dp = &procent[i];
+
+			if (cnp->cn_namelen == dp->d_namlen &&
+			    bcmp(pname, dp->d_name, dp->d_namlen) == 0) {
+			    	pfs_type = dp->d_pfstype;
+				goto found;
+			}
+		}
+		return (ENOENT);
+
+	found:
+		if (pfs_type == Pfile) {
+			nvp = procfs_findtextvp(procp);
+			if (nvp) {
+				VREF(nvp);
+				VOP_LOCK(nvp);
+			} else {
+				error = ENXIO;
+			}
+		} else {
+			error = procfs_allocvp(dvp->v_mount, &nvp,
+					pfs->pfs_pid, pfs_type);
+			if (error)
+				return (error);
+
+			nvp->v_type = VREG;
+			pfs = VTOPFS(nvp);
+		}
+		*vpp = nvp;
+		return (error);
+
+	default:
+		return (ENOTDIR);
+	}
+}
+
+/*
+ * readdir returns directory entries from pfsnode (vp).
+ *
+ * the strategy here with procfs is to generate a single
+ * directory entry at a time (struct pfsdent) and then
+ * copy that out to userland using uiomove.  a more efficent
+ * though more complex implementation, would try to minimize
+ * the number of calls to uiomove().  for procfs, this is
+ * hardly worth the added code complexity.
+ *
+ * this should just be done through read()
+ */
+procfs_readdir(ap)
+	struct vop_readdir_args *ap;
+{
+	struct uio *uio = ap->a_uio;
+	struct pfsdent d;
+	struct pfsdent *dp = &d;
+	struct pfsnode *pfs;
+	int error;
+	int count;
+	int i;
+
+	pfs = VTOPFS(ap->a_vp);
+
+	if (uio->uio_resid < UIO_MX)
+		return (EINVAL);
+	if (uio->uio_offset & (UIO_MX-1))
+		return (EINVAL);
+	if (uio->uio_offset < 0)
+		return (EINVAL);
+
+	error = 0;
+	count = 0;
+	i = uio->uio_offset / UIO_MX;
+
+	switch (pfs->pfs_type) {
+	/*
+	 * this is for the process-specific sub-directories.
+	 * all that is needed to is copy out all the entries
+	 * from the procent[] table (top of this file).
+	 */
+	case Pproc: {
+		while (uio->uio_resid >= UIO_MX) {
+			struct pfsnames *dt;
+
+			if (i >= Nprocent)
+				break;
+
+			dt = &procent[i];
+			
+			dp->d_reclen = UIO_MX;
+			dp->d_fileno = PROCFS_FILENO(pfs->pfs_pid, dt->d_pfstype);
+			dp->d_type = DT_REG;
+			dp->d_namlen = dt->d_namlen;
+			bcopy(dt->d_name, dp->d_name, sizeof(dt->d_name)-1);
+			error = uiomove((caddr_t) dp, UIO_MX, uio);
+			if (error)
+				break;
+			count += UIO_MX;
+			i++;
+		}
+
+	    	break;
+
+	    }
+
+	/*
+	 * this is for the root of the procfs filesystem
+	 * what is needed is a special entry for "curproc"
+	 * followed by an entry for each process on allproc
+#ifdef PROCFS_ZOMBIE
+	 * and zombproc.
+#endif
+	 */
+
+	case Proot: {
+		int pcnt;
+#ifdef PROCFS_ZOMBIE
+		int doingzomb = 0;
+#endif
+		volatile struct proc *p;
+
+		p = allproc;
+
+#define PROCFS_XFILES	1	/* number of other entries, like "curproc" */
+		pcnt = PROCFS_XFILES;
+
+		while (p && uio->uio_resid >= UIO_MX) {
+			bzero((char *) dp, UIO_MX);
+			dp->d_type = DT_DIR;
+			dp->d_reclen = UIO_MX;
+
+			switch (i) {
+			case 0:
+				/* ship out entry for "curproc" */
+				dp->d_fileno = PROCFS_FILENO(PID_MAX+1, Pproc);
+				dp->d_namlen = sprintf(dp->d_name, "curproc");
+				break;
+
+			default:
+				if (pcnt >= i) {
+					dp->d_fileno = PROCFS_FILENO(p->p_pid, Pproc);
+					dp->d_namlen = sprintf(dp->d_name, "%ld", (long) p->p_pid);
+				}
+
+				p = p->p_next;
+
+#ifdef PROCFS_ZOMBIE
+				if (p == 0 && doingzomb == 0) {
+					doingzomb = 1;
+					p = zombproc;
+				}
+#endif
+
+				if (pcnt++ < i)
+					continue;
+
+				break;
+			}
+			error = uiomove((caddr_t) dp, UIO_MX, uio);
+			if (error)
+				break;
+			count += UIO_MX;
+			i++;
+		}
+
+		break;
+
+	    }
+
+	default:
+		error = ENOTDIR;
+		break;
+	}
+
+	uio->uio_offset = i * UIO_MX;
+
+	return (error);
+}
+
+/*
+ * convert decimal ascii to pid_t
+ */
+static pid_t
+atopid(b, len)
+	const char *b;
+	u_int len;
+{
+	pid_t p = 0;
+
+	while (len--) {
+		char c = *b++;
+		if (c < '0' || c > '9')
+			return (NO_PID);
+		p = 10 * p + (c - '0');
+		if (p > PID_MAX)
+			return (NO_PID);
+	}
+
+	return (p);
+}
+
+/*
+ * procfs vnode operations.
+ */
+int (**procfs_vnodeop_p)();
+struct vnodeopv_entry_desc procfs_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, procfs_lookup },		/* lookup */
+	{ &vop_create_desc, procfs_create },		/* create */
+	{ &vop_mknod_desc, procfs_mknod },		/* mknod */
+	{ &vop_open_desc, procfs_open },		/* open */
+	{ &vop_close_desc, procfs_close },		/* close */
+	{ &vop_access_desc, procfs_access },		/* access */
+	{ &vop_getattr_desc, procfs_getattr },		/* getattr */
+	{ &vop_setattr_desc, procfs_setattr },		/* setattr */
+	{ &vop_read_desc, procfs_read },		/* read */
+	{ &vop_write_desc, procfs_write },		/* write */
+	{ &vop_ioctl_desc, procfs_ioctl },		/* ioctl */
+	{ &vop_select_desc, procfs_select },		/* select */
+	{ &vop_mmap_desc, procfs_mmap },		/* mmap */
+	{ &vop_fsync_desc, procfs_fsync },		/* fsync */
+	{ &vop_seek_desc, procfs_seek },		/* seek */
+	{ &vop_remove_desc, procfs_remove },		/* remove */
+	{ &vop_link_desc, procfs_link },		/* link */
+	{ &vop_rename_desc, procfs_rename },		/* rename */
+	{ &vop_mkdir_desc, procfs_mkdir },		/* mkdir */
+	{ &vop_rmdir_desc, procfs_rmdir },		/* rmdir */
+	{ &vop_symlink_desc, procfs_symlink },		/* symlink */
+	{ &vop_readdir_desc, procfs_readdir },		/* readdir */
+	{ &vop_readlink_desc, procfs_readlink },	/* readlink */
+	{ &vop_abortop_desc, procfs_abortop },		/* abortop */
+	{ &vop_inactive_desc, procfs_inactive },	/* inactive */
+	{ &vop_reclaim_desc, procfs_reclaim },		/* reclaim */
+	{ &vop_lock_desc, procfs_lock },		/* lock */
+	{ &vop_unlock_desc, procfs_unlock },		/* unlock */
+	{ &vop_bmap_desc, procfs_bmap },		/* bmap */
+	{ &vop_strategy_desc, procfs_strategy },	/* strategy */
+	{ &vop_print_desc, procfs_print },		/* print */
+	{ &vop_islocked_desc, procfs_islocked },	/* islocked */
+	{ &vop_pathconf_desc, procfs_pathconf },	/* pathconf */
+	{ &vop_advlock_desc, procfs_advlock },		/* advlock */
+	{ &vop_blkatoff_desc, procfs_blkatoff },	/* blkatoff */
+	{ &vop_valloc_desc, procfs_valloc },		/* valloc */
+	{ &vop_vfree_desc, procfs_vfree },		/* vfree */
+	{ &vop_truncate_desc, procfs_truncate },	/* truncate */
+	{ &vop_update_desc, procfs_update },		/* update */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc procfs_vnodeop_opv_desc =
+	{ &procfs_vnodeop_p, procfs_vnodeop_entries };
diff --git a/sys/miscfs/specfs/spec_vnops.c b/sys/miscfs/specfs/spec_vnops.c
new file mode 100644
index 0000000..111c517
--- /dev/null
+++ b/sys/miscfs/specfs/spec_vnops.c
@@ -0,0 +1,689 @@
+/*
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ *
+ *	@(#)spec_vnops.c	8.6 (Berkeley) 4/9/94
+ */
+
+#include <sys/param.h>
+#include <sys/proc.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+#include <sys/buf.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/vnode.h>
+#include <sys/stat.h>
+#include <sys/errno.h>
+#include <sys/ioctl.h>
+#include <sys/file.h>
+#include <sys/disklabel.h>
+#include <miscfs/specfs/specdev.h>
+
+/* symbolic sleep message strings for devices */
+char	devopn[] = "devopn";
+char	devio[] = "devio";
+char	devwait[] = "devwait";
+char	devin[] = "devin";
+char	devout[] = "devout";
+char	devioc[] = "devioc";
+char	devcls[] = "devcls";
+
+int (**spec_vnodeop_p)();
+struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, spec_lookup },		/* lookup */
+	{ &vop_create_desc, spec_create },		/* create */
+	{ &vop_mknod_desc, spec_mknod },		/* mknod */
+	{ &vop_open_desc, spec_open },			/* open */
+	{ &vop_close_desc, spec_close },		/* close */
+	{ &vop_access_desc, spec_access },		/* access */
+	{ &vop_getattr_desc, spec_getattr },		/* getattr */
+	{ &vop_setattr_desc, spec_setattr },		/* setattr */
+	{ &vop_read_desc, spec_read },			/* read */
+	{ &vop_write_desc, spec_write },		/* write */
+	{ &vop_ioctl_desc, spec_ioctl },		/* ioctl */
+	{ &vop_select_desc, spec_select },		/* select */
+	{ &vop_mmap_desc, spec_mmap },			/* mmap */
+	{ &vop_fsync_desc, spec_fsync },		/* fsync */
+	{ &vop_seek_desc, spec_seek },			/* seek */
+	{ &vop_remove_desc, spec_remove },		/* remove */
+	{ &vop_link_desc, spec_link },			/* link */
+	{ &vop_rename_desc, spec_rename },		/* rename */
+	{ &vop_mkdir_desc, spec_mkdir },		/* mkdir */
+	{ &vop_rmdir_desc, spec_rmdir },		/* rmdir */
+	{ &vop_symlink_desc, spec_symlink },		/* symlink */
+	{ &vop_readdir_desc, spec_readdir },		/* readdir */
+	{ &vop_readlink_desc, spec_readlink },		/* readlink */
+	{ &vop_abortop_desc, spec_abortop },		/* abortop */
+	{ &vop_inactive_desc, spec_inactive },		/* inactive */
+	{ &vop_reclaim_desc, spec_reclaim },		/* reclaim */
+	{ &vop_lock_desc, spec_lock },			/* lock */
+	{ &vop_unlock_desc, spec_unlock },		/* unlock */
+	{ &vop_bmap_desc, spec_bmap },			/* bmap */
+	{ &vop_strategy_desc, spec_strategy },		/* strategy */
+	{ &vop_print_desc, spec_print },		/* print */
+	{ &vop_islocked_desc, spec_islocked },		/* islocked */
+	{ &vop_pathconf_desc, spec_pathconf },		/* pathconf */
+	{ &vop_advlock_desc, spec_advlock },		/* advlock */
+	{ &vop_blkatoff_desc, spec_blkatoff },		/* blkatoff */
+	{ &vop_valloc_desc, spec_valloc },		/* valloc */
+	{ &vop_vfree_desc, spec_vfree },		/* vfree */
+	{ &vop_truncate_desc, spec_truncate },		/* truncate */
+	{ &vop_update_desc, spec_update },		/* update */
+	{ &vop_bwrite_desc, spec_bwrite },		/* bwrite */
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc spec_vnodeop_opv_desc =
+	{ &spec_vnodeop_p, spec_vnodeop_entries };
+
+/*
+ * Trivial lookup routine that always fails.
+ */
+int
+spec_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+
+	*ap->a_vpp = NULL;
+	return (ENOTDIR);
+}
+
+/*
+ * Open a special file.
+ */
+/* ARGSUSED */
+spec_open(ap)
+	struct vop_open_args /* {
+		struct vnode *a_vp;
+		int  a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct vnode *bvp, *vp = ap->a_vp;
+	dev_t bdev, dev = (dev_t)vp->v_rdev;
+	register int maj = major(dev);
+	int error;
+
+	/*
+	 * Don't allow open if fs is mounted -nodev.
+	 */
+	if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
+		return (ENXIO);
+
+	switch (vp->v_type) {
+
+	case VCHR:
+		if ((u_int)maj >= nchrdev)
+			return (ENXIO);
+		if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
+			/*
+			 * When running in very secure mode, do not allow
+			 * opens for writing of any disk character devices.
+			 */
+			if (securelevel >= 2 && isdisk(dev, VCHR))
+				return (EPERM);
+			/*
+			 * When running in secure mode, do not allow opens
+			 * for writing of /dev/mem, /dev/kmem, or character
+			 * devices whose corresponding block devices are
+			 * currently mounted.
+			 */
+			if (securelevel >= 1) {
+				if ((bdev = chrtoblk(dev)) != NODEV &&
+				    vfinddev(bdev, VBLK, &bvp) &&
+				    bvp->v_usecount > 0 &&
+				    (error = vfs_mountedon(bvp)))
+					return (error);
+				if (iskmemdev(dev))
+					return (EPERM);
+			}
+		}
+		VOP_UNLOCK(vp);
+		error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p);
+		VOP_LOCK(vp);
+		return (error);
+
+	case VBLK:
+		if ((u_int)maj >= nblkdev)
+			return (ENXIO);
+		/*
+		 * When running in very secure mode, do not allow
+		 * opens for writing of any disk block devices.
+		 */
+		if (securelevel >= 2 && ap->a_cred != FSCRED &&
+		    (ap->a_mode & FWRITE) && isdisk(dev, VBLK))
+			return (EPERM);
+		/*
+		 * Do not allow opens of block devices that are
+		 * currently mounted.
+		 */
+		if (error = vfs_mountedon(vp))
+			return (error);
+		return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p));
+	}
+	return (0);
+}
+
+/*
+ * Vnode op for read
+ */
+/* ARGSUSED */
+spec_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	register struct uio *uio = ap->a_uio;
+ 	struct proc *p = uio->uio_procp;
+	struct buf *bp;
+	daddr_t bn, nextbn;
+	long bsize, bscale;
+	struct partinfo dpart;
+	int n, on, majordev, (*ioctl)();
+	int error = 0;
+	dev_t dev;
+
+#ifdef DIAGNOSTIC
+	if (uio->uio_rw != UIO_READ)
+		panic("spec_read mode");
+	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
+		panic("spec_read proc");
+#endif
+	if (uio->uio_resid == 0)
+		return (0);
+
+	switch (vp->v_type) {
+
+	case VCHR:
+		VOP_UNLOCK(vp);
+		error = (*cdevsw[major(vp->v_rdev)].d_read)
+			(vp->v_rdev, uio, ap->a_ioflag);
+		VOP_LOCK(vp);
+		return (error);
+
+	case VBLK:
+		if (uio->uio_offset < 0)
+			return (EINVAL);
+		bsize = BLKDEV_IOSIZE;
+		dev = vp->v_rdev;
+		if ((majordev = major(dev)) < nblkdev &&
+		    (ioctl = bdevsw[majordev].d_ioctl) != NULL &&
+		    (*ioctl)(dev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0 &&
+		    dpart.part->p_fstype == FS_BSDFFS &&
+		    dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
+			bsize = dpart.part->p_frag * dpart.part->p_fsize;
+		bscale = bsize / DEV_BSIZE;
+		do {
+			bn = (uio->uio_offset / DEV_BSIZE) &~ (bscale - 1);
+			on = uio->uio_offset % bsize;
+			n = min((unsigned)(bsize - on), uio->uio_resid);
+			if (vp->v_lastr + bscale == bn) {
+				nextbn = bn + bscale;
+				error = breadn(vp, bn, (int)bsize, &nextbn,
+					(int *)&bsize, 1, NOCRED, &bp);
+			} else
+				error = bread(vp, bn, (int)bsize, NOCRED, &bp);
+			vp->v_lastr = bn;
+			n = min(n, bsize - bp->b_resid);
+			if (error) {
+				brelse(bp);
+				return (error);
+			}
+			error = uiomove((char *)bp->b_data + on, n, uio);
+			if (n + on == bsize)
+				bp->b_flags |= B_AGE;
+			brelse(bp);
+		} while (error == 0 && uio->uio_resid > 0 && n != 0);
+		return (error);
+
+	default:
+		panic("spec_read type");
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Vnode op for write
+ */
+/* ARGSUSED */
+spec_write(ap)
+	struct vop_write_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	register struct uio *uio = ap->a_uio;
+	struct proc *p = uio->uio_procp;
+	struct buf *bp;
+	daddr_t bn;
+	int bsize, blkmask;
+	struct partinfo dpart;
+	register int n, on;
+	int error = 0;
+
+#ifdef DIAGNOSTIC
+	if (uio->uio_rw != UIO_WRITE)
+		panic("spec_write mode");
+	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
+		panic("spec_write proc");
+#endif
+
+	switch (vp->v_type) {
+
+	case VCHR:
+		VOP_UNLOCK(vp);
+		error = (*cdevsw[major(vp->v_rdev)].d_write)
+			(vp->v_rdev, uio, ap->a_ioflag);
+		VOP_LOCK(vp);
+		return (error);
+
+	case VBLK:
+		if (uio->uio_resid == 0)
+			return (0);
+		if (uio->uio_offset < 0)
+			return (EINVAL);
+		bsize = BLKDEV_IOSIZE;
+		if ((*bdevsw[major(vp->v_rdev)].d_ioctl)(vp->v_rdev, DIOCGPART,
+		    (caddr_t)&dpart, FREAD, p) == 0) {
+			if (dpart.part->p_fstype == FS_BSDFFS &&
+			    dpart.part->p_frag != 0 && dpart.part->p_fsize != 0)
+				bsize = dpart.part->p_frag *
+				    dpart.part->p_fsize;
+		}
+		blkmask = (bsize / DEV_BSIZE) - 1;
+		do {
+			bn = (uio->uio_offset / DEV_BSIZE) &~ blkmask;
+			on = uio->uio_offset % bsize;
+			n = min((unsigned)(bsize - on), uio->uio_resid);
+			if (n == bsize)
+				bp = getblk(vp, bn, bsize, 0, 0);
+			else
+				error = bread(vp, bn, bsize, NOCRED, &bp);
+			n = min(n, bsize - bp->b_resid);
+			if (error) {
+				brelse(bp);
+				return (error);
+			}
+			error = uiomove((char *)bp->b_data + on, n, uio);
+			if (n + on == bsize) {
+				bp->b_flags |= B_AGE;
+				bawrite(bp);
+			} else
+				bdwrite(bp);
+		} while (error == 0 && uio->uio_resid > 0 && n != 0);
+		return (error);
+
+	default:
+		panic("spec_write type");
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Device ioctl operation.
+ */
+/* ARGSUSED */
+spec_ioctl(ap)
+	struct vop_ioctl_args /* {
+		struct vnode *a_vp;
+		int  a_command;
+		caddr_t  a_data;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	dev_t dev = ap->a_vp->v_rdev;
+
+	switch (ap->a_vp->v_type) {
+
+	case VCHR:
+		return ((*cdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data,
+		    ap->a_fflag, ap->a_p));
+
+	case VBLK:
+		if (ap->a_command == 0 && (int)ap->a_data == B_TAPE)
+			if (bdevsw[major(dev)].d_flags & B_TAPE)
+				return (0);
+			else
+				return (1);
+		return ((*bdevsw[major(dev)].d_ioctl)(dev, ap->a_command, ap->a_data,
+		   ap->a_fflag, ap->a_p));
+
+	default:
+		panic("spec_ioctl");
+		/* NOTREACHED */
+	}
+}
+
+/* ARGSUSED */
+spec_select(ap)
+	struct vop_select_args /* {
+		struct vnode *a_vp;
+		int  a_which;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	register dev_t dev;
+
+	switch (ap->a_vp->v_type) {
+
+	default:
+		return (1);		/* XXX */
+
+	case VCHR:
+		dev = ap->a_vp->v_rdev;
+		return (*cdevsw[major(dev)].d_select)(dev, ap->a_which, ap->a_p);
+	}
+}
+/*
+ * Synch buffers associated with a block device
+ */
+/* ARGSUSED */
+int
+spec_fsync(ap)
+	struct vop_fsync_args /* {
+		struct vnode *a_vp;
+		struct ucred *a_cred;
+		int  a_waitfor;
+		struct proc *a_p;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	register struct buf *bp;
+	struct buf *nbp;
+	int s;
+
+	if (vp->v_type == VCHR)
+		return (0);
+	/*
+	 * Flush all dirty buffers associated with a block device.
+	 */
+loop:
+	s = splbio();
+	for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = nbp) {
+		nbp = bp->b_vnbufs.le_next;
+		if ((bp->b_flags & B_BUSY))
+			continue;
+		if ((bp->b_flags & B_DELWRI) == 0)
+			panic("spec_fsync: not dirty");
+		bremfree(bp);
+		bp->b_flags |= B_BUSY;
+		splx(s);
+		bawrite(bp);
+		goto loop;
+	}
+	if (ap->a_waitfor == MNT_WAIT) {
+		while (vp->v_numoutput) {
+			vp->v_flag |= VBWAIT;
+			sleep((caddr_t)&vp->v_numoutput, PRIBIO + 1);
+		}
+#ifdef DIAGNOSTIC
+		if (vp->v_dirtyblkhd.lh_first) {
+			vprint("spec_fsync: dirty", vp);
+			goto loop;
+		}
+#endif
+	}
+	splx(s);
+	return (0);
+}
+
+/*
+ * Just call the device strategy routine
+ */
+spec_strategy(ap)
+	struct vop_strategy_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+
+	(*bdevsw[major(ap->a_bp->b_dev)].d_strategy)(ap->a_bp);
+	return (0);
+}
+
+/*
+ * This is a noop, simply returning what one has been given.
+ */
+spec_bmap(ap)
+	struct vop_bmap_args /* {
+		struct vnode *a_vp;
+		daddr_t  a_bn;
+		struct vnode **a_vpp;
+		daddr_t *a_bnp;
+	} */ *ap;
+{
+
+	if (ap->a_vpp != NULL)
+		*ap->a_vpp = ap->a_vp;
+	if (ap->a_bnp != NULL)
+		*ap->a_bnp = ap->a_bn;
+	return (0);
+}
+
+/*
+ * At the moment we do not do any locking.
+ */
+/* ARGSUSED */
+spec_lock(ap)
+	struct vop_lock_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/* ARGSUSED */
+spec_unlock(ap)
+	struct vop_unlock_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return (0);
+}
+
+/*
+ * Device close routine
+ */
+/* ARGSUSED */
+spec_close(ap)
+	struct vop_close_args /* {
+		struct vnode *a_vp;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	register struct vnode *vp = ap->a_vp;
+	dev_t dev = vp->v_rdev;
+	int (*devclose) __P((dev_t, int, int, struct proc *));
+	int mode, error;
+
+	switch (vp->v_type) {
+
+	case VCHR:
+		/*
+		 * Hack: a tty device that is a controlling terminal
+		 * has a reference from the session structure.
+		 * We cannot easily tell that a character device is
+		 * a controlling terminal, unless it is the closing
+		 * process' controlling terminal.  In that case,
+		 * if the reference count is 2 (this last descriptor
+		 * plus the session), release the reference from the session.
+		 */
+		if (vcount(vp) == 2 && ap->a_p &&
+		    vp == ap->a_p->p_session->s_ttyvp) {
+			vrele(vp);
+			ap->a_p->p_session->s_ttyvp = NULL;
+		}
+		/*
+		 * If the vnode is locked, then we are in the midst
+		 * of forcably closing the device, otherwise we only
+		 * close on last reference.
+		 */
+		if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
+			return (0);
+		devclose = cdevsw[major(dev)].d_close;
+		mode = S_IFCHR;
+		break;
+
+	case VBLK:
+		/*
+		 * On last close of a block device (that isn't mounted)
+		 * we must invalidate any in core blocks, so that
+		 * we can, for instance, change floppy disks.
+		 */
+		if (error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0))
+			return (error);
+		/*
+		 * We do not want to really close the device if it
+		 * is still in use unless we are trying to close it
+		 * forcibly. Since every use (buffer, vnode, swap, cmap)
+		 * holds a reference to the vnode, and because we mark
+		 * any other vnodes that alias this device, when the
+		 * sum of the reference counts on all the aliased
+		 * vnodes descends to one, we are on last close.
+		 */
+		if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
+			return (0);
+		devclose = bdevsw[major(dev)].d_close;
+		mode = S_IFBLK;
+		break;
+
+	default:
+		panic("spec_close: not special");
+	}
+
+	return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p));
+}
+
+/*
+ * Print out the contents of a special device vnode.
+ */
+spec_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev),
+		minor(ap->a_vp->v_rdev));
+}
+
+/*
+ * Return POSIX pathconf information applicable to special devices.
+ */
+spec_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+
+	switch (ap->a_name) {
+	case _PC_LINK_MAX:
+		*ap->a_retval = LINK_MAX;
+		return (0);
+	case _PC_MAX_CANON:
+		*ap->a_retval = MAX_CANON;
+		return (0);
+	case _PC_MAX_INPUT:
+		*ap->a_retval = MAX_INPUT;
+		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_VDISABLE:
+		*ap->a_retval = _POSIX_VDISABLE;
+		return (0);
+	default:
+		return (EINVAL);
+	}
+	/* NOTREACHED */
+}
+
+/*
+ * Special device advisory byte-level locks.
+ */
+/* ARGSUSED */
+spec_advlock(ap)
+	struct vop_advlock_args /* {
+		struct vnode *a_vp;
+		caddr_t  a_id;
+		int  a_op;
+		struct flock *a_fl;
+		int  a_flags;
+	} */ *ap;
+{
+
+	return (EOPNOTSUPP);
+}
+
+/*
+ * Special device failed operation
+ */
+spec_ebadf()
+{
+
+	return (EBADF);
+}
+
+/*
+ * Special device bad operation
+ */
+spec_badop()
+{
+
+	panic("spec_badop called");
+	/* NOTREACHED */
+}
diff --git a/sys/miscfs/specfs/specdev.h b/sys/miscfs/specfs/specdev.h
new file mode 100644
index 0000000..a13b66e
--- /dev/null
+++ b/sys/miscfs/specfs/specdev.h
@@ -0,0 +1,127 @@
+/*
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ *
+ *	@(#)specdev.h	8.2 (Berkeley) 2/2/94
+ */
+
+/*
+ * This structure defines the information maintained about
+ * special devices. It is allocated in checkalias and freed
+ * in vgone.
+ */
+struct specinfo {
+	struct	vnode **si_hashchain;
+	struct	vnode *si_specnext;
+	long	si_flags;
+	dev_t	si_rdev;
+};
+/*
+ * Exported shorthand
+ */
+#define v_rdev v_specinfo->si_rdev
+#define v_hashchain v_specinfo->si_hashchain
+#define v_specnext v_specinfo->si_specnext
+#define v_specflags v_specinfo->si_flags
+
+/*
+ * Flags for specinfo
+ */
+#define	SI_MOUNTEDON	0x0001	/* block special device is mounted on */
+
+/*
+ * Special device management
+ */
+#define	SPECHSZ	64
+#if	((SPECHSZ&(SPECHSZ-1)) == 0)
+#define	SPECHASH(rdev)	(((rdev>>5)+(rdev))&(SPECHSZ-1))
+#else
+#define	SPECHASH(rdev)	(((unsigned)((rdev>>5)+(rdev)))%SPECHSZ)
+#endif
+
+struct vnode *speclisth[SPECHSZ];
+
+/*
+ * Prototypes for special file operations on vnodes.
+ */
+extern	int (**spec_vnodeop_p)();
+struct	nameidata;
+struct	componentname;
+struct	ucred;
+struct	flock;
+struct	buf;
+struct	uio;
+
+int	spec_badop(),
+	spec_ebadf();
+
+int	spec_lookup __P((struct vop_lookup_args *));
+#define spec_create ((int (*) __P((struct  vop_create_args *)))spec_badop)
+#define spec_mknod ((int (*) __P((struct  vop_mknod_args *)))spec_badop)
+int	spec_open __P((struct vop_open_args *));
+int	spec_close __P((struct vop_close_args *));
+#define spec_access ((int (*) __P((struct  vop_access_args *)))spec_ebadf)
+#define spec_getattr ((int (*) __P((struct  vop_getattr_args *)))spec_ebadf)
+#define spec_setattr ((int (*) __P((struct  vop_setattr_args *)))spec_ebadf)
+int	spec_read __P((struct vop_read_args *));
+int	spec_write __P((struct vop_write_args *));
+int	spec_ioctl __P((struct vop_ioctl_args *));
+int	spec_select __P((struct vop_select_args *));
+#define spec_mmap ((int (*) __P((struct  vop_mmap_args *)))spec_badop)
+int	spec_fsync __P((struct  vop_fsync_args *));
+#define spec_seek ((int (*) __P((struct  vop_seek_args *)))spec_badop)
+#define spec_remove ((int (*) __P((struct  vop_remove_args *)))spec_badop)
+#define spec_link ((int (*) __P((struct  vop_link_args *)))spec_badop)
+#define spec_rename ((int (*) __P((struct  vop_rename_args *)))spec_badop)
+#define spec_mkdir ((int (*) __P((struct  vop_mkdir_args *)))spec_badop)
+#define spec_rmdir ((int (*) __P((struct  vop_rmdir_args *)))spec_badop)
+#define spec_symlink ((int (*) __P((struct  vop_symlink_args *)))spec_badop)
+#define spec_readdir ((int (*) __P((struct  vop_readdir_args *)))spec_badop)
+#define spec_readlink ((int (*) __P((struct  vop_readlink_args *)))spec_badop)
+#define spec_abortop ((int (*) __P((struct  vop_abortop_args *)))spec_badop)
+#define spec_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
+#define spec_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
+int	spec_lock __P((struct vop_lock_args *));
+int	spec_unlock __P((struct vop_unlock_args *));
+int	spec_bmap __P((struct vop_bmap_args *));
+int	spec_strategy __P((struct vop_strategy_args *));
+int	spec_print __P((struct vop_print_args *));
+#define spec_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
+int	spec_pathconf __P((struct vop_pathconf_args *));
+int	spec_advlock __P((struct vop_advlock_args *));
+#define spec_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))spec_badop)
+#define spec_valloc ((int (*) __P((struct  vop_valloc_args *)))spec_badop)
+#define spec_reallocblks \
+	((int (*) __P((struct  vop_reallocblks_args *)))spec_badop)
+#define spec_vfree ((int (*) __P((struct  vop_vfree_args *)))spec_badop)
+#define spec_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
+#define spec_update ((int (*) __P((struct  vop_update_args *)))nullop)
+#define spec_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
diff --git a/sys/miscfs/umapfs/umap.h b/sys/miscfs/umapfs/umap.h
new file mode 100644
index 0000000..9f4d1e7
--- /dev/null
+++ b/sys/miscfs/umapfs/umap.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * the UCLA Ficus project.
+ *
+ * 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.
+ *
+ *	@(#)umap.h	8.3 (Berkeley) 1/21/94
+ *
+ * @(#)null_vnops.c       1.5 (Berkeley) 7/10/92
+ */
+
+#define MAPFILEENTRIES 64
+#define GMAPFILEENTRIES 16
+#define NOBODY 32767
+#define NULLGROUP 65534
+
+struct umap_args {
+	char		*target;	/* Target of loopback  */
+	int 		nentries;       /* # of entries in user map array */
+	int 		gnentries;	/* # of entries in group map array */
+	u_long 		(*mapdata)[2];	/* pointer to array of user mappings */
+	u_long 		(*gmapdata)[2];	/* pointer to array of group mappings */
+};
+
+struct umap_mount {
+	struct mount	*umapm_vfs;
+	struct vnode	*umapm_rootvp;	/* Reference to root umap_node */
+	int             info_nentries;  /* number of uid mappings */
+	int		info_gnentries;	/* number of gid mappings */
+	u_long		info_mapdata[MAPFILEENTRIES][2]; /* mapping data for 
+	    user mapping in ficus */
+	u_long		info_gmapdata[GMAPFILEENTRIES][2]; /*mapping data for 
+	    group mapping in ficus */
+};
+
+#ifdef KERNEL
+/*
+ * A cache of vnode references
+ */
+struct umap_node {
+	struct umap_node	*umap_forw;	/* Hash chain */
+	struct umap_node	*umap_back;
+	struct vnode	*umap_lowervp;	/* Aliased vnode - VREFed once */
+	struct vnode	*umap_vnode;	/* Back pointer to vnode/umap_node */
+};
+
+extern int umap_node_create __P((struct mount *mp, struct vnode *target, struct vnode **vpp));
+extern u_long umap_reverse_findid __P((u_long id, u_long map[][2], int nentries));
+extern void umap_mapids __P((struct mount *v_mount, struct ucred *credp));
+
+#define	MOUNTTOUMAPMOUNT(mp) ((struct umap_mount *)((mp)->mnt_data))
+#define	VTOUMAP(vp) ((struct umap_node *)(vp)->v_data)
+#define UMAPTOV(xp) ((xp)->umap_vnode)
+#ifdef UMAPFS_DIAGNOSTIC
+extern struct vnode *umap_checkvp __P((struct vnode *vp, char *fil, int lno));
+#define	UMAPVPTOLOWERVP(vp) umap_checkvp((vp), __FILE__, __LINE__)
+#else
+#define	UMAPVPTOLOWERVP(vp) (VTOUMAP(vp)->umap_lowervp)
+#endif
+
+extern int (**umap_vnodeop_p)();
+extern struct vfsops umap_vfsops;
+#endif /* KERNEL */
diff --git a/sys/miscfs/umapfs/umap_subr.c b/sys/miscfs/umapfs/umap_subr.c
new file mode 100644
index 0000000..6f1f077
--- /dev/null
+++ b/sys/miscfs/umapfs/umap_subr.c
@@ -0,0 +1,397 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)umap_subr.c	8.6 (Berkeley) 1/26/94
+ *
+ * $Id: lofs_subr.c, v 1.11 1992/05/30 10:05:43 jsp Exp jsp $
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/umapfs/umap.h>
+
+#define LOG2_SIZEVNODE 7		/* log2(sizeof struct vnode) */
+#define	NUMAPNODECACHE 16
+#define	UMAP_NHASH(vp) ((((u_long) vp)>>LOG2_SIZEVNODE) & (NUMAPNODECACHE-1))
+
+/*
+ * Null layer cache:
+ * Each cache entry holds a reference to the target vnode
+ * along with a pointer to the alias vnode.  When an
+ * entry is added the target vnode is VREF'd.  When the
+ * alias is removed the target vnode is vrele'd.
+ */
+
+/*
+ * Cache head
+ */
+struct umap_node_cache {
+	struct umap_node	*ac_forw;
+	struct umap_node	*ac_back;
+};
+
+static struct umap_node_cache umap_node_cache[NUMAPNODECACHE];
+
+/*
+ * Initialise cache headers
+ */
+umapfs_init()
+{
+	struct umap_node_cache *ac;
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_init\n");		/* printed during system boot */
+#endif
+
+	for (ac = umap_node_cache; ac < umap_node_cache + NUMAPNODECACHE; ac++)
+		ac->ac_forw = ac->ac_back = (struct umap_node *) ac;
+}
+
+/*
+ * Compute hash list for given target vnode
+ */
+static struct umap_node_cache *
+umap_node_hash(targetvp)
+	struct vnode *targetvp;
+{
+
+	return (&umap_node_cache[UMAP_NHASH(targetvp)]);
+}
+
+/*
+ * umap_findid is called by various routines in umap_vnodeops.c to
+ * find a user or group id in a map.
+ */
+static u_long
+umap_findid(id, map, nentries)
+	u_long id;
+	u_long map[][2];
+	int nentries;
+{
+	int i;
+
+	/* Find uid entry in map */
+	i = 0;
+	while ((i<nentries) && ((map[i][0]) != id))
+		i++;
+
+	if (i < nentries)
+		return (map[i][1]);
+	else
+		return (-1);
+
+}
+
+/*
+ * umap_reverse_findid is called by umap_getattr() in umap_vnodeops.c to
+ * find a user or group id in a map, in reverse.
+ */
+u_long
+umap_reverse_findid(id, map, nentries)
+	u_long id;
+	u_long map[][2];
+	int nentries;
+{
+	int i;
+
+	/* Find uid entry in map */
+	i = 0;
+	while ((i<nentries) && ((map[i][1]) != id))
+		i++;
+
+	if (i < nentries)
+		return (map[i][0]);
+	else
+		return (-1);
+
+}
+
+/*
+ * Return alias for target vnode if already exists, else 0.
+ */
+static struct vnode *
+umap_node_find(mp, targetvp)
+	struct mount *mp;
+	struct vnode *targetvp;
+{
+	struct umap_node_cache *hd;
+	struct umap_node *a;
+	struct vnode *vp;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umap_node_find(mp = %x, target = %x)\n", mp, targetvp);
+#endif
+
+	/*
+	 * Find hash base, and then search the (two-way) linked
+	 * list looking for a umap_node structure which is referencing
+	 * the target vnode.  If found, the increment the umap_node
+	 * reference count (but NOT the target vnode's VREF counter).
+	 */
+	hd = umap_node_hash(targetvp);
+
+ loop:
+	for (a = hd->ac_forw; a != (struct umap_node *) hd; a = a->umap_forw) {
+		if (a->umap_lowervp == targetvp &&
+		    a->umap_vnode->v_mount == mp) {
+			vp = UMAPTOV(a);
+			/*
+			 * We need vget for the VXLOCK
+			 * stuff, but we don't want to lock
+			 * the lower node.
+			 */
+			if (vget(vp, 0)) {
+#ifdef UMAPFS_DIAGNOSTIC
+				printf ("umap_node_find: vget failed.\n");
+#endif
+				goto loop;
+			}
+			return (vp);
+		}
+	}
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umap_node_find(%x, %x): NOT found\n", mp, targetvp);
+#endif
+
+	return (0);
+}
+
+/*
+ * Make a new umap_node node.
+ * Vp is the alias vnode, lofsvp is the target vnode.
+ * Maintain a reference to (targetvp).
+ */
+static int
+umap_node_alloc(mp, lowervp, vpp)
+	struct mount *mp;
+	struct vnode *lowervp;
+	struct vnode **vpp;
+{
+	struct umap_node_cache *hd;
+	struct umap_node *xp;
+	struct vnode *othervp, *vp;
+	int error;
+
+	if (error = getnewvnode(VT_UMAP, mp, umap_vnodeop_p, vpp))
+		return (error);
+	vp = *vpp;
+
+	MALLOC(xp, struct umap_node *, sizeof(struct umap_node),
+	    M_TEMP, M_WAITOK);
+	vp->v_type = lowervp->v_type;
+	xp->umap_vnode = vp;
+	vp->v_data = xp;
+	xp->umap_lowervp = lowervp;
+	/*
+	 * Before we insert our new node onto the hash chains,
+	 * check to see if someone else has beaten us to it.
+	 * (We could have slept in MALLOC.)
+	 */
+	if (othervp = umap_node_find(lowervp)) {
+		FREE(xp, M_TEMP);
+		vp->v_type = VBAD;	/* node is discarded */
+		vp->v_usecount = 0;	/* XXX */
+		*vpp = othervp;
+		return (0);
+	}
+	VREF(lowervp);   /* Extra VREF will be vrele'd in umap_node_create */
+	hd = umap_node_hash(lowervp);
+	insque(xp, hd);
+	return (0);
+}
+
+
+/*
+ * Try to find an existing umap_node vnode refering
+ * to it, otherwise make a new umap_node vnode which
+ * contains a reference to the target vnode.
+ */
+int
+umap_node_create(mp, targetvp, newvpp)
+	struct mount *mp;
+	struct vnode *targetvp;
+	struct vnode **newvpp;
+{
+	struct vnode *aliasvp;
+
+	if (aliasvp = umap_node_find(mp, targetvp)) {
+		/*
+		 * Take another reference to the alias vnode
+		 */
+#ifdef UMAPFS_DIAGNOSTIC
+		vprint("umap_node_create: exists", ap->umap_vnode);
+#endif
+		/* VREF(aliasvp); */
+	} else {
+		int error;
+
+		/*
+		 * Get new vnode.
+		 */
+#ifdef UMAPFS_DIAGNOSTIC
+		printf("umap_node_create: create new alias vnode\n");
+#endif
+		/*
+		 * Make new vnode reference the umap_node.
+		 */
+		if (error = umap_node_alloc(mp, targetvp, &aliasvp))
+			return (error);
+
+		/*
+		 * aliasvp is already VREF'd by getnewvnode()
+		 */
+	}
+
+	vrele(targetvp);
+
+#ifdef UMAPFS_DIAGNOSTIC
+	vprint("umap_node_create: alias", aliasvp);
+	vprint("umap_node_create: target", targetvp);
+#endif
+
+	*newvpp = aliasvp;
+	return (0);
+}
+
+#ifdef UMAPFS_DIAGNOSTIC
+int umap_checkvp_barrier = 1;
+struct vnode *
+umap_checkvp(vp, fil, lno)
+	struct vnode *vp;
+	char *fil;
+	int lno;
+{
+	struct umap_node *a = VTOUMAP(vp);
+#if 0
+	/*
+	 * Can't do this check because vop_reclaim runs
+	 * with funny vop vector.
+	 */
+	if (vp->v_op != umap_vnodeop_p) {
+		printf ("umap_checkvp: on non-umap-node\n");
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic("umap_checkvp");
+	}
+#endif
+	if (a->umap_lowervp == NULL) {
+		/* Should never happen */
+		int i; u_long *p;
+		printf("vp = %x, ZERO ptr\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic("umap_checkvp");
+	}
+	if (a->umap_lowervp->v_usecount < 1) {
+		int i; u_long *p;
+		printf("vp = %x, unref'ed lowervp\n", vp);
+		for (p = (u_long *) a, i = 0; i < 8; i++)
+			printf(" %x", p[i]);
+		printf("\n");
+		/* wait for debugger */
+		while (umap_checkvp_barrier) /*WAIT*/ ;
+		panic ("umap with unref'ed lowervp");
+	}
+#if 0
+	printf("umap %x/%d -> %x/%d [%s, %d]\n",
+	        a->umap_vnode, a->umap_vnode->v_usecount,
+		a->umap_lowervp, a->umap_lowervp->v_usecount,
+		fil, lno);
+#endif
+	return (a->umap_lowervp);
+}
+#endif
+
+/* umap_mapids maps all of the ids in a credential, both user and group. */
+
+void
+umap_mapids(v_mount, credp)
+	struct mount *v_mount;
+	struct ucred *credp;
+{
+	int i, unentries, gnentries;
+	u_long *groupmap, *usermap;
+	uid_t uid;
+	gid_t gid;
+
+	unentries =  MOUNTTOUMAPMOUNT(v_mount)->info_nentries;
+	usermap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_mapdata[0][0]);
+	gnentries =  MOUNTTOUMAPMOUNT(v_mount)->info_gnentries;
+	groupmap =  &(MOUNTTOUMAPMOUNT(v_mount)->info_gmapdata[0][0]);
+
+	/* Find uid entry in map */
+
+	uid = (uid_t) umap_findid(credp->cr_uid, usermap, unentries);
+
+	if (uid != -1)
+		credp->cr_uid = uid;
+	else
+		credp->cr_uid = (uid_t) NOBODY;
+
+#ifdef notdef
+	/* cr_gid is the same as cr_groups[0] in 4BSD */
+
+	/* Find gid entry in map */
+
+	gid = (gid_t) umap_findid(credp->cr_gid, groupmap, gnentries);
+
+	if (gid != -1)
+		credp->cr_gid = gid;
+	else
+		credp->cr_gid = NULLGROUP;
+#endif
+
+	/* Now we must map each of the set of groups in the cr_groups 
+		structure. */
+
+	i = 0;
+	while (credp->cr_groups[i] != 0) {
+		gid = (gid_t) umap_findid(credp->cr_groups[i],
+					groupmap, gnentries);
+
+		if (gid != -1)
+			credp->cr_groups[i++] = gid;
+		else
+			credp->cr_groups[i++] = NULLGROUP;
+	}
+}
diff --git a/sys/miscfs/umapfs/umap_vfsops.c b/sys/miscfs/umapfs/umap_vfsops.c
new file mode 100644
index 0000000..2480a85
--- /dev/null
+++ b/sys/miscfs/umapfs/umap_vfsops.c
@@ -0,0 +1,407 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * the UCLA Ficus project.
+ *
+ * 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.
+ *
+ *	@(#)umap_vfsops.c	8.3 (Berkeley) 1/21/94
+ *
+ * @(#)null_vfsops.c       1.5 (Berkeley) 7/10/92
+ */
+
+/*
+ * Umap Layer
+ * (See mount_umap(8) for a description of this layer.)
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <miscfs/umapfs/umap.h>
+
+/*
+ * Mount umap layer
+ */
+int
+umapfs_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	struct umap_args args;
+	struct vnode *lowerrootvp, *vp;
+	struct vnode *umapm_rootvp;
+	struct umap_mount *amp;
+	u_int size;
+	int error;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_mount(mp = %x)\n", mp);
+#endif
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE) {
+		return (EOPNOTSUPP);
+		/* return (VFS_MOUNT(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, path, data, ndp, p));*/
+	}
+
+	/*
+	 * Get argument
+	 */
+	if (error = copyin(data, (caddr_t)&args, sizeof(struct umap_args)))
+		return (error);
+
+	/*
+	 * Find lower node
+	 */
+	NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF,
+		UIO_USERSPACE, args.target, p);
+	if (error = namei(ndp))
+		return (error);
+
+	/*
+	 * Sanity check on lower vnode
+	 */
+	lowerrootvp = ndp->ni_vp;
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("vp = %x, check for VDIR...\n", lowerrootvp);
+#endif
+	vrele(ndp->ni_dvp);
+	ndp->ni_dvp = 0;
+
+	if (lowerrootvp->v_type != VDIR) {
+		vput(lowerrootvp);
+		return (EINVAL);
+	}
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("mp = %x\n", mp);
+#endif
+
+	amp = (struct umap_mount *) malloc(sizeof(struct umap_mount),
+				M_UFSMNT, M_WAITOK);	/* XXX */
+
+	/*
+	 * Save reference to underlying FS
+	 */
+	amp->umapm_vfs = lowerrootvp->v_mount;
+
+	/* 
+	 * Now copy in the number of entries and maps for umap mapping.
+	 */
+	amp->info_nentries = args.nentries;
+	amp->info_gnentries = args.gnentries;
+	error = copyin(args.mapdata, (caddr_t)amp->info_mapdata, 
+	    2*sizeof(u_long)*args.nentries);
+	if (error)
+		return (error);
+
+#ifdef UMAP_DIAGNOSTIC
+	printf("umap_mount:nentries %d\n",args.nentries);
+	for (i = 0; i < args.nentries; i++)
+		printf("   %d maps to %d\n", amp->info_mapdata[i][0],
+	 	    amp->info_mapdata[i][1]);
+#endif
+
+	error = copyin(args.gmapdata, (caddr_t)amp->info_gmapdata, 
+	    2*sizeof(u_long)*args.nentries);
+	if (error)
+		return (error);
+
+#ifdef UMAP_DIAGNOSTIC
+	printf("umap_mount:gnentries %d\n",args.gnentries);
+	for (i = 0; i < args.gnentries; i++)
+		printf("	group %d maps to %d\n", 
+		    amp->info_gmapdata[i][0],
+	 	    amp->info_gmapdata[i][1]);
+#endif
+
+
+	/*
+	 * Save reference.  Each mount also holds
+	 * a reference on the root vnode.
+	 */
+	error = umap_node_create(mp, lowerrootvp, &vp);
+	/*
+	 * Unlock the node (either the lower or the alias)
+	 */
+	VOP_UNLOCK(vp);
+	/*
+	 * Make sure the node alias worked
+	 */
+	if (error) {
+		vrele(lowerrootvp);
+		free(amp, M_UFSMNT);	/* XXX */
+		return (error);
+	}
+
+	/*
+	 * Keep a held reference to the root vnode.
+	 * It is vrele'd in umapfs_unmount.
+	 */
+	umapm_rootvp = vp;
+	umapm_rootvp->v_flag |= VROOT;
+	amp->umapm_rootvp = umapm_rootvp;
+	if (UMAPVPTOLOWERVP(umapm_rootvp)->v_mount->mnt_flag & MNT_LOCAL)
+		mp->mnt_flag |= MNT_LOCAL;
+	mp->mnt_data = (qaddr_t) amp;
+	getnewfsid(mp, MOUNT_LOFS);
+
+	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+	(void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 
+	    &size);
+	bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size);
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_mount: lower %s, alias at %s\n",
+		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
+#endif
+	return (0);
+}
+
+/*
+ * VFS start.  Nothing needed here - the start routine
+ * on the underlying filesystem will have been called
+ * when that filesystem was mounted.
+ */
+int
+umapfs_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+	return (0);
+	/* return (VFS_START(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, flags, p)); */
+}
+
+/*
+ * Free reference to umap layer
+ */
+int
+umapfs_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	struct vnode *umapm_rootvp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
+	int error;
+	int flags = 0;
+	extern int doforce;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_unmount(mp = %x)\n", mp);
+#endif
+
+	if (mntflags & MNT_FORCE) {
+		/* lofs can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	/*
+	 * Clear out buffer cache.  I don't think we
+	 * ever get anything cached at this level at the
+	 * moment, but who knows...
+	 */
+#ifdef notyet
+	mntflushbuf(mp, 0); 
+	if (mntinvalbuf(mp, 1))
+		return (EBUSY);
+#endif
+	if (umapm_rootvp->v_usecount > 1)
+		return (EBUSY);
+	if (error = vflush(mp, umapm_rootvp, flags))
+		return (error);
+
+#ifdef UMAPFS_DIAGNOSTIC
+	vprint("alias root of lower", umapm_rootvp);
+#endif	 
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vrele(umapm_rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(umapm_rootvp);
+	/*
+	 * Finally, throw away the umap_mount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+	return (0);
+}
+
+int
+umapfs_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct vnode *vp;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_root(mp = %x, vp = %x->%x)\n", mp,
+			MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
+			UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp)
+			);
+#endif
+
+	/*
+	 * Return locked reference to root.
+	 */
+	vp = MOUNTTOUMAPMOUNT(mp)->umapm_rootvp;
+	VREF(vp);
+	VOP_LOCK(vp);
+	*vpp = vp;
+	return (0);
+}
+
+int
+umapfs_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+	return (VFS_QUOTACTL(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, cmd, uid, arg, p));
+}
+
+int
+umapfs_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+	int error;
+	struct statfs mstat;
+
+#ifdef UMAPFS_DIAGNOSTIC
+	printf("umapfs_statfs(mp = %x, vp = %x->%x)\n", mp,
+			MOUNTTOUMAPMOUNT(mp)->umapm_rootvp,
+			UMAPVPTOLOWERVP(MOUNTTOUMAPMOUNT(mp)->umapm_rootvp)
+			);
+#endif
+
+	bzero(&mstat, sizeof(mstat));
+
+	error = VFS_STATFS(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, &mstat, p);
+	if (error)
+		return (error);
+
+	/* now copy across the "interesting" information and fake the rest */
+	sbp->f_type = mstat.f_type;
+	sbp->f_flags = mstat.f_flags;
+	sbp->f_bsize = mstat.f_bsize;
+	sbp->f_iosize = mstat.f_iosize;
+	sbp->f_blocks = mstat.f_blocks;
+	sbp->f_bfree = mstat.f_bfree;
+	sbp->f_bavail = mstat.f_bavail;
+	sbp->f_files = mstat.f_files;
+	sbp->f_ffree = mstat.f_ffree;
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+int
+umapfs_sync(mp, waitfor, cred, p)
+	struct mount *mp;
+	int waitfor;
+	struct ucred *cred;
+	struct proc *p;
+{
+	/*
+	 * XXX - Assumes no data cached at umap layer.
+	 */
+	return (0);
+}
+
+int
+umapfs_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+	
+	return (VFS_VGET(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, ino, vpp));
+}
+
+int
+umapfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
+	struct mount *mp;
+	struct fid *fidp;
+	struct mbuf *nam;
+	struct vnode **vpp;
+	int *exflagsp;
+	struct ucred**credanonp;
+{
+
+	return (VFS_FHTOVP(MOUNTTOUMAPMOUNT(mp)->umapm_vfs, fidp, nam, vpp, exflagsp,credanonp));
+}
+
+int
+umapfs_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+	return (VFS_VPTOFH(UMAPVPTOLOWERVP(vp), fhp));
+}
+
+int umapfs_init __P((void));
+
+struct vfsops umap_vfsops = {
+	umapfs_mount,
+	umapfs_start,
+	umapfs_unmount,
+	umapfs_root,
+	umapfs_quotactl,
+	umapfs_statfs,
+	umapfs_sync,
+	umapfs_vget,
+	umapfs_fhtovp,
+	umapfs_vptofh,
+	umapfs_init,
+};
diff --git a/sys/miscfs/umapfs/umap_vnops.c b/sys/miscfs/umapfs/umap_vnops.c
new file mode 100644
index 0000000..287804e
--- /dev/null
+++ b/sys/miscfs/umapfs/umap_vnops.c
@@ -0,0 +1,488 @@
+/*
+ * Copyright (c) 1992, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * the UCLA Ficus project.
+ *
+ * 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.
+ *
+ *	@(#)umap_vnops.c	8.3 (Berkeley) 1/5/94
+ */
+
+/*
+ * Umap Layer
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+#include <miscfs/umapfs/umap.h>
+
+
+int umap_bug_bypass = 0;   /* for debugging: enables bypass printf'ing */
+
+/*
+ * This is the 10-Apr-92 bypass routine.
+ * See null_vnops.c:null_bypass for more details.
+ */ 
+int
+umap_bypass(ap)
+	struct vop_generic_args /* {
+		struct vnodeop_desc *a_desc;
+		<other random data follows, presumably>
+	} */ *ap;
+{
+	extern int (**umap_vnodeop_p)();  /* not extern, really "forward" */
+	struct ucred **credpp = 0, *credp = 0;
+	struct ucred *savecredp, *savecompcredp = 0;
+	struct ucred *compcredp = 0;
+	struct vnode **this_vp_p;
+	int error;
+	struct vnode *old_vps[VDESC_MAX_VPS];
+	struct vnode *vp1 = 0;
+	struct vnode **vps_p[VDESC_MAX_VPS];
+	struct vnode ***vppp;
+	struct vnodeop_desc *descp = ap->a_desc;
+	int reles, i;
+	struct componentname **compnamepp = 0;
+
+	if (umap_bug_bypass)
+		printf ("umap_bypass: %s\n", descp->vdesc_name);
+
+#ifdef SAFETY
+	/*
+	 * We require at least one vp.
+	 */
+	if (descp->vdesc_vp_offsets == NULL ||
+	    descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
+		panic ("umap_bypass: no vp's in map.\n");
+#endif
+
+	/*
+	 * Map the vnodes going in.
+	 * Later, we'll invoke the operation based on
+	 * the first mapped vnode's operation vector.
+	 */
+	reles = descp->vdesc_flags;
+	for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
+		if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
+			break;   /* bail out at end of list */
+		vps_p[i] = this_vp_p = 
+			VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[i], ap);
+
+		if (i == 0) {
+			vp1 = *vps_p[0];
+		}
+
+		/*
+		 * We're not guaranteed that any but the first vnode
+		 * are of our type.  Check for and don't map any
+		 * that aren't.  (Must map first vp or vclean fails.)
+		 */
+
+		if (i && (*this_vp_p)->v_op != umap_vnodeop_p) {
+			old_vps[i] = NULL;
+		} else {
+			old_vps[i] = *this_vp_p;
+			*(vps_p[i]) = UMAPVPTOLOWERVP(*this_vp_p);
+			if (reles & 1)
+				VREF(*this_vp_p);
+		}
+			
+	}
+
+	/*
+	 * Fix the credentials.  (That's the purpose of this layer.)
+	 */
+
+	if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
+
+		credpp = VOPARG_OFFSETTO(struct ucred**, 
+		    descp->vdesc_cred_offset, ap);
+
+		/* Save old values */
+
+		savecredp = (*credpp);
+		(*credpp) = crdup(savecredp);
+		credp = *credpp;
+
+		if (umap_bug_bypass && credp->cr_uid != 0)
+			printf("umap_bypass: user was %d, group %d\n", 
+			    credp->cr_uid, credp->cr_gid);
+
+		/* Map all ids in the credential structure. */
+
+		umap_mapids(vp1->v_mount, credp);
+
+		if (umap_bug_bypass && credp->cr_uid != 0)
+			printf("umap_bypass: user now %d, group %d\n", 
+			    credp->cr_uid, credp->cr_gid);
+	}
+
+	/* BSD often keeps a credential in the componentname structure
+	 * for speed.  If there is one, it better get mapped, too. 
+	 */
+
+	if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
+
+		compnamepp = VOPARG_OFFSETTO(struct componentname**, 
+		    descp->vdesc_componentname_offset, ap);
+
+		compcredp = (*compnamepp)->cn_cred;
+		savecompcredp = compcredp;
+		compcredp = (*compnamepp)->cn_cred = crdup(savecompcredp);
+
+		if (umap_bug_bypass && compcredp->cr_uid != 0)
+			printf("umap_bypass: component credit user was %d, group %d\n", 
+			    compcredp->cr_uid, compcredp->cr_gid);
+
+		/* Map all ids in the credential structure. */
+
+		umap_mapids(vp1->v_mount, compcredp);
+
+		if (umap_bug_bypass && compcredp->cr_uid != 0)
+			printf("umap_bypass: component credit user now %d, group %d\n", 
+			    compcredp->cr_uid, compcredp->cr_gid);
+	}
+
+	/*
+	 * Call the operation on the lower layer
+	 * with the modified argument structure.
+	 */
+	error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
+
+	/*
+	 * Maintain the illusion of call-by-value
+	 * by restoring vnodes in the argument structure
+	 * to their original value.
+	 */
+	reles = descp->vdesc_flags;
+	for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
+		if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
+			break;   /* bail out at end of list */
+		if (old_vps[i]) {
+			*(vps_p[i]) = old_vps[i];
+			if (reles & 1)
+				vrele(*(vps_p[i]));
+		};
+	};
+
+	/*
+	 * Map the possible out-going vpp
+	 * (Assumes that the lower layer always returns
+	 * a VREF'ed vpp unless it gets an error.)
+	 */
+	if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
+	    !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
+	    !error) {
+		if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
+			goto out;
+		vppp = VOPARG_OFFSETTO(struct vnode***,
+				 descp->vdesc_vpp_offset, ap);
+		error = umap_node_create(old_vps[0]->v_mount, **vppp, *vppp);
+	};
+
+ out:
+	/* 
+	 * Free duplicate cred structure and restore old one.
+	 */
+	if (descp->vdesc_cred_offset != VDESC_NO_OFFSET) {
+		if (umap_bug_bypass && credp && credp->cr_uid != 0)
+			printf("umap_bypass: returning-user was %d\n",
+					credp->cr_uid);
+
+		crfree(credp);
+		(*credpp) = savecredp;
+		if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
+		 	printf("umap_bypass: returning-user now %d\n\n", 
+			    (*credpp)->cr_uid);
+	}
+
+	if (descp->vdesc_componentname_offset != VDESC_NO_OFFSET) {
+		if (umap_bug_bypass && compcredp && compcredp->cr_uid != 0)
+		printf("umap_bypass: returning-component-user was %d\n", 
+				compcredp->cr_uid);
+
+		crfree(compcredp);
+		(*compnamepp)->cn_cred = savecompcredp;
+		if (umap_bug_bypass && credpp && (*credpp)->cr_uid != 0)
+		 	printf("umap_bypass: returning-component-user now %d\n", 
+					compcredp->cr_uid);
+	}
+
+	return (error);
+}
+
+
+/*
+ *  We handle getattr to change the fsid.
+ */
+int
+umap_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	short uid, gid;
+	int error, tmpid, nentries, gnentries;
+	u_long (*mapdata)[2], (*gmapdata)[2];
+	struct vnode **vp1p;
+	struct vnodeop_desc *descp = ap->a_desc;
+
+	if (error = umap_bypass(ap))
+		return (error);
+	/* Requires that arguments be restored. */
+	ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
+
+	/*
+	 * Umap needs to map the uid and gid returned by a stat
+	 * into the proper values for this site.  This involves
+	 * finding the returned uid in the mapping information,
+	 * translating it into the uid on the other end,
+	 * and filling in the proper field in the vattr
+	 * structure pointed to by ap->a_vap.  The group
+	 * is easier, since currently all groups will be
+	 * translate to the NULLGROUP.
+	 */
+
+	/* Find entry in map */
+
+	uid = ap->a_vap->va_uid;
+	gid = ap->a_vap->va_gid;
+	if (umap_bug_bypass)
+		printf("umap_getattr: mapped uid = %d, mapped gid = %d\n", uid, 
+		    gid);
+
+	vp1p = VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
+	nentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_nentries;
+	mapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_mapdata);
+	gnentries =  MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gnentries;
+	gmapdata =  (MOUNTTOUMAPMOUNT((*vp1p)->v_mount)->info_gmapdata);
+
+	/* Reverse map the uid for the vnode.  Since it's a reverse
+		map, we can't use umap_mapids() to do it. */
+
+	tmpid = umap_reverse_findid(uid, mapdata, nentries);
+
+	if (tmpid != -1) {
+
+		ap->a_vap->va_uid = (uid_t) tmpid;
+		if (umap_bug_bypass)
+			printf("umap_getattr: original uid = %d\n", uid);
+	} else 
+		ap->a_vap->va_uid = (uid_t) NOBODY;
+
+	/* Reverse map the gid for the vnode. */
+
+	tmpid = umap_reverse_findid(gid, gmapdata, gnentries);
+
+	if (tmpid != -1) {
+
+		ap->a_vap->va_gid = (gid_t) tmpid;
+		if (umap_bug_bypass)
+			printf("umap_getattr: original gid = %d\n", gid);
+	} else
+		ap->a_vap->va_gid = (gid_t) NULLGROUP;
+	
+	return (0);
+}
+
+int
+umap_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	/*
+	 * Do nothing (and _don't_ bypass).
+	 * Wait to vrele lowervp until reclaim,
+	 * so that until then our umap_node is in the
+	 * cache and reusable.
+	 *
+	 */
+	return (0);
+}
+
+int
+umap_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct umap_node *xp = VTOUMAP(vp);
+	struct vnode *lowervp = xp->umap_lowervp;
+	
+	/* After this assignment, this node will not be re-used. */
+	xp->umap_lowervp = NULL;
+	remque(xp);
+	FREE(vp->v_data, M_TEMP);
+	vp->v_data = NULL;
+	vrele(lowervp);
+	return (0);
+}
+
+int
+umap_strategy(ap)
+	struct vop_strategy_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+	struct buf *bp = ap->a_bp;
+	int error;
+	struct vnode *savedvp;
+
+	savedvp = bp->b_vp;
+	bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
+
+	error = VOP_STRATEGY(ap->a_bp);
+
+	bp->b_vp = savedvp;
+
+	return (error);
+}
+
+int
+umap_bwrite(ap)
+	struct vop_bwrite_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+	struct buf *bp = ap->a_bp;
+	int error;
+	struct vnode *savedvp;
+
+	savedvp = bp->b_vp;
+	bp->b_vp = UMAPVPTOLOWERVP(bp->b_vp);
+
+	error = VOP_BWRITE(ap->a_bp);
+
+	bp->b_vp = savedvp;
+
+	return (error);
+}
+
+
+int
+umap_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	printf("\ttag VT_UMAPFS, vp=%x, lowervp=%x\n", vp, UMAPVPTOLOWERVP(vp));
+	return (0);
+}
+
+int
+umap_rename(ap)
+	struct vop_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;
+	} */ *ap;
+{
+	int error;
+	struct componentname *compnamep;
+	struct ucred *compcredp, *savecompcredp;
+	struct vnode *vp;
+
+	/*
+	 * Rename is irregular, having two componentname structures.
+	 * We need to map the cre in the second structure,
+	 * and then bypass takes care of the rest.
+	 */
+
+	vp = ap->a_fdvp;
+	compnamep = ap->a_tcnp;
+	compcredp = compnamep->cn_cred;
+
+	savecompcredp = compcredp;
+	compcredp = compnamep->cn_cred = crdup(savecompcredp);
+
+	if (umap_bug_bypass && compcredp->cr_uid != 0)
+		printf("umap_rename: rename component credit user was %d, group %d\n", 
+		    compcredp->cr_uid, compcredp->cr_gid);
+
+	/* Map all ids in the credential structure. */
+
+	umap_mapids(vp->v_mount, compcredp);
+
+	if (umap_bug_bypass && compcredp->cr_uid != 0)
+		printf("umap_rename: rename component credit user now %d, group %d\n", 
+		    compcredp->cr_uid, compcredp->cr_gid);
+
+	error = umap_bypass(ap);
+	
+	/* Restore the additional mapped componentname cred structure. */
+
+	crfree(compcredp);
+	compnamep->cn_cred = savecompcredp;
+
+	return error;
+}
+
+/*
+ * Global vfs data structures
+ */
+/*
+ * XXX - strategy, bwrite are hand coded currently.  They should
+ * go away with a merged buffer/block cache.
+ *
+ */
+int (**umap_vnodeop_p)();
+struct vnodeopv_entry_desc umap_vnodeop_entries[] = {
+	{ &vop_default_desc, umap_bypass },
+
+	{ &vop_getattr_desc, umap_getattr },
+	{ &vop_inactive_desc, umap_inactive },
+	{ &vop_reclaim_desc, umap_reclaim },
+	{ &vop_print_desc, umap_print },
+	{ &vop_rename_desc, umap_rename },
+
+	{ &vop_strategy_desc, umap_strategy },
+	{ &vop_bwrite_desc, umap_bwrite },
+
+	{ (struct vnodeop_desc*) NULL, (int(*)()) NULL }
+};
+struct vnodeopv_desc umap_vnodeop_opv_desc =
+	{ &umap_vnodeop_p, umap_vnodeop_entries };
diff --git a/sys/miscfs/union/README b/sys/miscfs/union/README
new file mode 100644
index 0000000..14a4769
--- /dev/null
+++ b/sys/miscfs/union/README
@@ -0,0 +1,7 @@
+If you plan on using union mounts, then you should consider replacing
+"libc/gen/opendir.c" in the C library with the file "libc.opendir.c"
+in this directory.  The replacement version of opendir() automatically
+removes duplicate names when a union stack is encountered.  You will
+then need to rebuild the C library and all commands.
+
+@(#)README	8.1 (Berkeley) 2/15/94
diff --git a/sys/miscfs/union/libc.opendir.c b/sys/miscfs/union/libc.opendir.c
new file mode 100644
index 0000000..99ed58b
--- /dev/null
+++ b/sys/miscfs/union/libc.opendir.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (c) 1983, 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char orig_sccsid[] = "@(#)opendir.c	8.2 (Berkeley) 2/12/94";
+static char sccsid[] = "@(#)libc.opendir.c	8.1 (Berkeley) 2/15/94";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <sys/mount.h>
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/*
+ * open a directory.
+ */
+DIR *
+opendir(name)
+	const char *name;
+{
+	DIR *dirp;
+	int fd;
+	int incr;
+	struct statfs sfb;
+
+	if ((fd = open(name, 0)) == -1)
+		return (NULL);
+	if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
+	    (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
+		close(fd);
+		return (NULL);
+	}
+
+	/*
+	 * If CLBYTES is an exact multiple of DIRBLKSIZ, use a CLBYTES
+	 * buffer that it cluster boundary aligned.
+	 * Hopefully this can be a big win someday by allowing page
+	 * trades trade to user space to be done by getdirentries()
+	 */
+	if ((CLBYTES % DIRBLKSIZ) == 0)
+		incr = CLBYTES;
+	else
+		incr = DIRBLKSIZ;
+
+#ifdef MOUNT_UNION
+	/*
+	 * Determine whether this directory is the top of a union stack.
+	 */
+	if (fstatfs(fd, &sfb) < 0) {
+		free(dirp);
+		close(fd);
+		return (NULL);
+	}
+
+	if (sfb.f_type == MOUNT_UNION) {
+		int len = 0;
+		int space = 0;
+		char *buf = 0;
+		char *ddptr = 0;
+		int n;
+		struct dirent **dpv;
+
+		/*
+		 * The strategy here is to read all the directory
+		 * entries into a buffer, sort the buffer, and
+		 * remove duplicate entries by setting the inode
+		 * number to zero.
+		 */
+
+		/*
+		 * Fixup dd_loc to be non-zero to fake out readdir
+		 */
+		dirp->dd_loc = sizeof(void *);
+
+		do {
+			/*
+			 * Always make at least DIRBLKSIZ bytes
+			 * available to getdirentries
+			 */
+			if (space < DIRBLKSIZ) {
+				space += incr;
+				len += incr;
+				buf = realloc(buf, len);
+				if (buf == NULL) {
+					free(dirp);
+					close(fd);
+					return (NULL);
+				}
+				ddptr = buf + (len - space) + dirp->dd_loc;
+			}
+
+			n = getdirentries(fd, ddptr, space, &dirp->dd_seek);
+			if (n > 0) {
+				ddptr += n;
+				space -= n;
+			}
+		} while (n > 0);
+
+		/*
+		 * There is now a buffer full of (possibly) duplicate
+		 * names.
+		 */
+		dirp->dd_buf = buf;
+
+		/*
+		 * Go round this loop twice...
+		 *
+		 * Scan through the buffer, counting entries.
+		 * On the second pass, save pointers to each one.
+		 * Then sort the pointers and remove duplicate names.
+		 */
+		for (dpv = 0;;) {
+			n = 0;
+			ddptr = buf + dirp->dd_loc;
+			while (ddptr < buf + len) {
+				struct dirent *dp;
+
+				dp = (struct dirent *) ddptr;
+				if ((int)dp & 03)
+					break;
+				if ((dp->d_reclen <= 0) ||
+				    (dp->d_reclen > (buf + len + 1 - ddptr)))
+					break;
+				ddptr += dp->d_reclen;
+				if (dp->d_fileno) {
+					if (dpv)
+						dpv[n] = dp;
+					n++;
+				}
+			}
+
+			if (dpv) {
+				struct dirent *xp;
+
+				/*
+				 * If and when whiteouts happen,
+				 * this sort would need to be stable.
+				 */
+				heapsort(dpv, n, sizeof(*dpv), alphasort);
+
+				dpv[n] = NULL;
+				xp = NULL;
+
+				/*
+				 * Scan through the buffer in sort order,
+				 * zapping the inode number of any
+				 * duplicate names.
+				 */
+				for (n = 0; dpv[n]; n++) {
+					struct dirent *dp = dpv[n];
+
+					if ((xp == NULL) ||
+					    strcmp(dp->d_name, xp->d_name))
+						xp = dp;
+					else
+						dp->d_fileno = 0;
+				}
+
+				free(dpv);
+				break;
+			} else {
+				dpv = malloc((n+1) * sizeof(struct dirent *));
+				if (dpv == NULL)
+					break;
+			}
+		}
+
+		dirp->dd_len = len;
+		dirp->dd_size = ddptr - dirp->dd_buf;
+	} else
+#endif /* MOUNT_UNION */
+	{
+		dirp->dd_len = incr;
+		dirp->dd_buf = malloc(dirp->dd_len);
+		if (dirp->dd_buf == NULL) {
+			free(dirp);
+			close (fd);
+			return (NULL);
+		}
+		dirp->dd_seek = 0;
+		dirp->dd_loc = 0;
+	}
+
+	dirp->dd_fd = fd;
+
+	/*
+	 * Set up seek point for rewinddir.
+	 */
+	dirp->dd_rewind = telldir(dirp);
+
+	return (dirp);
+}
diff --git a/sys/miscfs/union/union.h b/sys/miscfs/union/union.h
new file mode 100644
index 0000000..463218a
--- /dev/null
+++ b/sys/miscfs/union/union.h
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 1994 The Regents of the University of California.
+ * Copyright (c) 1994 Jan-Simon Pendry.
+ * All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)union.h	8.2 (Berkeley) 2/17/94
+ */
+
+struct union_args {
+	char		*target;	/* Target of loopback  */
+	int		mntflags;	/* Options on the mount */
+};
+
+#define UNMNT_ABOVE	0x0001		/* Target appears below mount point */
+#define UNMNT_BELOW	0x0002		/* Target appears below mount point */
+#define UNMNT_REPLACE	0x0003		/* Target replaces mount point */
+#define UNMNT_OPMASK	0x0003
+
+struct union_mount {
+	struct vnode	*um_uppervp;
+	struct vnode	*um_lowervp;
+	struct ucred	*um_cred;	/* Credentials of user calling mount */
+	int		um_cmode;	/* cmask from mount process */
+	int		um_op;		/* Operation mode */
+};
+
+#ifdef KERNEL
+
+/*
+ * DEFDIRMODE is the mode bits used to create a shadow directory.
+ */
+#define VRWXMODE (VREAD|VWRITE|VEXEC)
+#define VRWMODE (VREAD|VWRITE)
+#define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
+#define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
+
+/*
+ * A cache of vnode references
+ */
+struct union_node {
+	LIST_ENTRY(union_node)	un_cache;	/* Hash chain */
+	struct vnode		*un_vnode;	/* Back pointer */
+	struct vnode	        *un_uppervp;	/* overlaying object */
+	struct vnode	        *un_lowervp;	/* underlying object */
+	struct vnode		*un_dirvp;	/* Parent dir of uppervp */
+	char			*un_path;	/* saved component name */
+	int			un_hash;	/* saved un_path hash value */
+	int			un_openl;	/* # of opens on lowervp */
+	int			un_flags;
+#ifdef DIAGNOSTIC
+	pid_t			un_pid;
+#endif
+};
+
+#define UN_WANT		0x01
+#define UN_LOCKED	0x02
+#define UN_ULOCK	0x04		/* Upper node is locked */
+#define UN_KLOCK	0x08		/* Keep upper node locked on vput */
+
+extern int union_allocvp __P((struct vnode **, struct mount *,
+				struct vnode *, struct vnode *,
+				struct componentname *, struct vnode *,
+				struct vnode *));
+extern int union_copyfile __P((struct proc *, struct ucred *,
+				struct vnode *, struct vnode *));
+extern int union_mkshadow __P((struct union_mount *, struct vnode *,
+				struct componentname *, struct vnode **));
+extern int union_vn_create __P((struct vnode **, struct union_node *,
+				struct proc *));
+extern int union_cn_close __P((struct vnode *, int, struct ucred *,
+				struct proc *));
+extern void union_removed_upper __P((struct union_node *un));
+extern struct vnode *union_lowervp __P((struct vnode *));
+extern void union_newlower __P((struct union_node *, struct vnode *));
+extern void union_newupper __P((struct union_node *, struct vnode *));
+
+#define	MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
+#define	VTOUNION(vp) ((struct union_node *)(vp)->v_data)
+#define	UNIONTOV(un) ((un)->un_vnode)
+#define	LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
+#define	UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
+#define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
+
+extern int (**union_vnodeop_p)();
+extern struct vfsops union_vfsops;
+#endif /* KERNEL */
diff --git a/sys/miscfs/union/union_subr.c b/sys/miscfs/union/union_subr.c
new file mode 100644
index 0000000..77947d1
--- /dev/null
+++ b/sys/miscfs/union/union_subr.c
@@ -0,0 +1,744 @@
+/*
+ * Copyright (c) 1994 Jan-Simon Pendry
+ * Copyright (c) 1994
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)union_subr.c	8.4 (Berkeley) 2/17/94
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/kernel.h>
+#include <sys/vnode.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/file.h>
+#include <sys/filedesc.h>
+#include <sys/queue.h>
+#include <miscfs/union/union.h>
+
+#ifdef DIAGNOSTIC
+#include <sys/proc.h>
+#endif
+
+/* must be power of two, otherwise change UNION_HASH() */
+#define NHASH 32
+
+/* unsigned int ... */
+#define UNION_HASH(u, l) \
+	(((((unsigned long) (u)) + ((unsigned long) l)) >> 8) & (NHASH-1))
+
+static LIST_HEAD(unhead, union_node) unhead[NHASH];
+static int unvplock[NHASH];
+
+int
+union_init()
+{
+	int i;
+
+	for (i = 0; i < NHASH; i++)
+		LIST_INIT(&unhead[i]);
+	bzero((caddr_t) unvplock, sizeof(unvplock));
+}
+
+static int
+union_list_lock(ix)
+	int ix;
+{
+
+	if (unvplock[ix] & UN_LOCKED) {
+		unvplock[ix] |= UN_WANT;
+		sleep((caddr_t) &unvplock[ix], PINOD);
+		return (1);
+	}
+
+	unvplock[ix] |= UN_LOCKED;
+
+	return (0);
+}
+
+static void
+union_list_unlock(ix)
+	int ix;
+{
+
+	unvplock[ix] &= ~UN_LOCKED;
+
+	if (unvplock[ix] & UN_WANT) {
+		unvplock[ix] &= ~UN_WANT;
+		wakeup((caddr_t) &unvplock[ix]);
+	}
+}
+
+void
+union_updatevp(un, uppervp, lowervp)
+	struct union_node *un;
+	struct vnode *uppervp;
+	struct vnode *lowervp;
+{
+	int ohash = UNION_HASH(un->un_uppervp, un->un_lowervp);
+	int nhash = UNION_HASH(uppervp, lowervp);
+
+	if (ohash != nhash) {
+		/*
+		 * Ensure locking is ordered from lower to higher
+		 * to avoid deadlocks.
+		 */
+		if (nhash < ohash) {
+			int t = ohash;
+			ohash = nhash;
+			nhash = t;
+		}
+
+		while (union_list_lock(ohash))
+			continue;
+
+		while (union_list_lock(nhash))
+			continue;
+
+		LIST_REMOVE(un, un_cache);
+		union_list_unlock(ohash);
+	} else {	
+		while (union_list_lock(nhash))
+			continue;
+	}
+
+	if (un->un_lowervp != lowervp) {
+		if (un->un_lowervp) {
+			vrele(un->un_lowervp);
+			if (un->un_path) {
+				free(un->un_path, M_TEMP);
+				un->un_path = 0;
+			}
+			if (un->un_dirvp) {
+				vrele(un->un_dirvp);
+				un->un_dirvp = NULLVP;
+			}
+		}
+		un->un_lowervp = lowervp;
+	}
+
+	if (un->un_uppervp != uppervp) {
+		if (un->un_uppervp)
+			vrele(un->un_uppervp);
+
+		un->un_uppervp = uppervp;
+	}
+
+	if (ohash != nhash)
+		LIST_INSERT_HEAD(&unhead[nhash], un, un_cache);
+
+	union_list_unlock(nhash);
+}
+
+void
+union_newlower(un, lowervp)
+	struct union_node *un;
+	struct vnode *lowervp;
+{
+
+	union_updatevp(un, un->un_uppervp, lowervp);
+}
+
+void
+union_newupper(un, uppervp)
+	struct union_node *un;
+	struct vnode *uppervp;
+{
+
+	union_updatevp(un, uppervp, un->un_lowervp);
+}
+
+/*
+ * allocate a union_node/vnode pair.  the vnode is
+ * referenced and locked.  the new vnode is returned
+ * via (vpp).  (mp) is the mountpoint of the union filesystem,
+ * (dvp) is the parent directory where the upper layer object
+ * should exist (but doesn't) and (cnp) is the componentname
+ * information which is partially copied to allow the upper
+ * layer object to be created at a later time.  (uppervp)
+ * and (lowervp) reference the upper and lower layer objects
+ * being mapped.  either, but not both, can be nil.
+ * if supplied, (uppervp) is locked.
+ * the reference is either maintained in the new union_node
+ * object which is allocated, or they are vrele'd.
+ *
+ * all union_nodes are maintained on a singly-linked
+ * list.  new nodes are only allocated when they cannot
+ * be found on this list.  entries on the list are
+ * removed when the vfs reclaim entry is called.
+ *
+ * a single lock is kept for the entire list.  this is
+ * needed because the getnewvnode() function can block
+ * waiting for a vnode to become free, in which case there
+ * may be more than one process trying to get the same
+ * vnode.  this lock is only taken if we are going to
+ * call getnewvnode, since the kernel itself is single-threaded.
+ *
+ * if an entry is found on the list, then call vget() to
+ * take a reference.  this is done because there may be
+ * zero references to it and so it needs to removed from
+ * the vnode free list.
+ */
+int
+union_allocvp(vpp, mp, undvp, dvp, cnp, uppervp, lowervp)
+	struct vnode **vpp;
+	struct mount *mp;
+	struct vnode *undvp;
+	struct vnode *dvp;		/* may be null */
+	struct componentname *cnp;	/* may be null */
+	struct vnode *uppervp;		/* may be null */
+	struct vnode *lowervp;		/* may be null */
+{
+	int error;
+	struct union_node *un;
+	struct union_node **pp;
+	struct vnode *xlowervp = NULLVP;
+	int hash;
+	int try;
+
+	if (uppervp == NULLVP && lowervp == NULLVP)
+		panic("union: unidentifiable allocation");
+
+	if (uppervp && lowervp && (uppervp->v_type != lowervp->v_type)) {
+		xlowervp = lowervp;
+		lowervp = NULLVP;
+	}
+
+loop:
+	for (try = 0; try < 3; try++) {
+		switch (try) {
+		case 0:
+			if (lowervp == NULLVP)
+				continue;
+			hash = UNION_HASH(uppervp, lowervp);
+			break;
+
+		case 1:
+			if (uppervp == NULLVP)
+				continue;
+			hash = UNION_HASH(uppervp, NULLVP);
+			break;
+
+		case 2:
+			if (lowervp == NULLVP)
+				continue;
+			hash = UNION_HASH(NULLVP, lowervp);
+			break;
+		}
+
+		while (union_list_lock(hash))
+			continue;
+
+		for (un = unhead[hash].lh_first; un != 0;
+					un = un->un_cache.le_next) {
+			if ((un->un_lowervp == lowervp ||
+			     un->un_lowervp == NULLVP) &&
+			    (un->un_uppervp == uppervp ||
+			     un->un_uppervp == NULLVP) &&
+			    (UNIONTOV(un)->v_mount == mp)) {
+				if (vget(UNIONTOV(un), 0)) {
+					union_list_unlock(hash);
+					goto loop;
+				}
+				break;
+			}
+		}
+
+		union_list_unlock(hash);
+
+		if (un)
+			break;
+	}
+
+	if (un) {
+		/*
+		 * Obtain a lock on the union_node.
+		 * uppervp is locked, though un->un_uppervp
+		 * may not be.  this doesn't break the locking
+		 * hierarchy since in the case that un->un_uppervp
+		 * is not yet locked it will be vrele'd and replaced
+		 * with uppervp.
+		 */
+
+		if ((dvp != NULLVP) && (uppervp == dvp)) {
+			/*
+			 * Access ``.'', so (un) will already
+			 * be locked.  Since this process has
+			 * the lock on (uppervp) no other
+			 * process can hold the lock on (un).
+			 */
+#ifdef DIAGNOSTIC
+			if ((un->un_flags & UN_LOCKED) == 0)
+				panic("union: . not locked");
+			else if (curproc && un->un_pid != curproc->p_pid &&
+				    un->un_pid > -1 && curproc->p_pid > -1)
+				panic("union: allocvp not lock owner");
+#endif
+		} else {
+			if (un->un_flags & UN_LOCKED) {
+				vrele(UNIONTOV(un));
+				un->un_flags |= UN_WANT;
+				sleep((caddr_t) &un->un_flags, PINOD);
+				goto loop;
+			}
+			un->un_flags |= UN_LOCKED;
+
+#ifdef DIAGNOSTIC
+			if (curproc)
+				un->un_pid = curproc->p_pid;
+			else
+				un->un_pid = -1;
+#endif
+		}
+
+		/*
+		 * At this point, the union_node is locked,
+		 * un->un_uppervp may not be locked, and uppervp
+		 * is locked or nil.
+		 */
+
+		/*
+		 * Save information about the upper layer.
+		 */
+		if (uppervp != un->un_uppervp) {
+			union_newupper(un, uppervp);
+		} else if (uppervp) {
+			vrele(uppervp);
+		}
+
+		if (un->un_uppervp) {
+			un->un_flags |= UN_ULOCK;
+			un->un_flags &= ~UN_KLOCK;
+		}
+
+		/*
+		 * Save information about the lower layer.
+		 * This needs to keep track of pathname
+		 * and directory information which union_vn_create
+		 * might need.
+		 */
+		if (lowervp != un->un_lowervp) {
+			union_newlower(un, lowervp);
+			if (cnp && (lowervp != NULLVP) &&
+			    (lowervp->v_type == VREG)) {
+				un->un_hash = cnp->cn_hash;
+				un->un_path = malloc(cnp->cn_namelen+1,
+						M_TEMP, M_WAITOK);
+				bcopy(cnp->cn_nameptr, un->un_path,
+						cnp->cn_namelen);
+				un->un_path[cnp->cn_namelen] = '\0';
+				VREF(dvp);
+				un->un_dirvp = dvp;
+			}
+		} else if (lowervp) {
+			vrele(lowervp);
+		}
+		*vpp = UNIONTOV(un);
+		return (0);
+	}
+
+	/*
+	 * otherwise lock the vp list while we call getnewvnode
+	 * since that can block.
+	 */ 
+	hash = UNION_HASH(uppervp, lowervp);
+
+	if (union_list_lock(hash))
+		goto loop;
+
+	error = getnewvnode(VT_UNION, mp, union_vnodeop_p, vpp);
+	if (error) {
+		if (uppervp) {
+			if (dvp == uppervp)
+				vrele(uppervp);
+			else
+				vput(uppervp);
+		}
+		if (lowervp)
+			vrele(lowervp);
+
+		goto out;
+	}
+
+	MALLOC((*vpp)->v_data, void *, sizeof(struct union_node),
+		M_TEMP, M_WAITOK);
+
+	if (uppervp)
+		(*vpp)->v_type = uppervp->v_type;
+	else
+		(*vpp)->v_type = lowervp->v_type;
+	un = VTOUNION(*vpp);
+	un->un_vnode = *vpp;
+	un->un_uppervp = uppervp;
+	un->un_lowervp = lowervp;
+	un->un_openl = 0;
+	un->un_flags = UN_LOCKED;
+	if (un->un_uppervp)
+		un->un_flags |= UN_ULOCK;
+#ifdef DIAGNOSTIC
+	if (curproc)
+		un->un_pid = curproc->p_pid;
+	else
+		un->un_pid = -1;
+#endif
+	if (cnp && (lowervp != NULLVP) && (lowervp->v_type == VREG)) {
+		un->un_hash = cnp->cn_hash;
+		un->un_path = malloc(cnp->cn_namelen+1, M_TEMP, M_WAITOK);
+		bcopy(cnp->cn_nameptr, un->un_path, cnp->cn_namelen);
+		un->un_path[cnp->cn_namelen] = '\0';
+		VREF(dvp);
+		un->un_dirvp = dvp;
+	} else {
+		un->un_hash = 0;
+		un->un_path = 0;
+		un->un_dirvp = 0;
+	}
+
+	LIST_INSERT_HEAD(&unhead[hash], un, un_cache);
+
+	if (xlowervp)
+		vrele(xlowervp);
+
+out:
+	union_list_unlock(hash);
+
+	return (error);
+}
+
+int
+union_freevp(vp)
+	struct vnode *vp;
+{
+	struct union_node *un = VTOUNION(vp);
+
+	LIST_REMOVE(un, un_cache);
+
+	if (un->un_uppervp)
+		vrele(un->un_uppervp);
+	if (un->un_lowervp)
+		vrele(un->un_lowervp);
+	if (un->un_dirvp)
+		vrele(un->un_dirvp);
+	if (un->un_path)
+		free(un->un_path, M_TEMP);
+
+	FREE(vp->v_data, M_TEMP);
+	vp->v_data = 0;
+
+	return (0);
+}
+
+/*
+ * copyfile.  copy the vnode (fvp) to the vnode (tvp)
+ * using a sequence of reads and writes.  both (fvp)
+ * and (tvp) are locked on entry and exit.
+ */
+int
+union_copyfile(p, cred, fvp, tvp)
+	struct proc *p;
+	struct ucred *cred;
+	struct vnode *fvp;
+	struct vnode *tvp;
+{
+	char *buf;
+	struct uio uio;
+	struct iovec iov;
+	int error = 0;
+
+	/*
+	 * strategy:
+	 * allocate a buffer of size MAXBSIZE.
+	 * loop doing reads and writes, keeping track
+	 * of the current uio offset.
+	 * give up at the first sign of trouble.
+	 */
+
+	uio.uio_procp = p;
+	uio.uio_segflg = UIO_SYSSPACE;
+	uio.uio_offset = 0;
+
+	VOP_UNLOCK(fvp);				/* XXX */
+	LEASE_CHECK(fvp, p, cred, LEASE_READ);
+	VOP_LOCK(fvp);					/* XXX */
+	VOP_UNLOCK(tvp);				/* XXX */
+	LEASE_CHECK(tvp, p, cred, LEASE_WRITE);
+	VOP_LOCK(tvp);					/* XXX */
+
+	buf = malloc(MAXBSIZE, M_TEMP, M_WAITOK);
+
+	/* ugly loop follows... */
+	do {
+		off_t offset = uio.uio_offset;
+
+		uio.uio_iov = &iov;
+		uio.uio_iovcnt = 1;
+		iov.iov_base = buf;
+		iov.iov_len = MAXBSIZE;
+		uio.uio_resid = iov.iov_len;
+		uio.uio_rw = UIO_READ;
+		error = VOP_READ(fvp, &uio, 0, cred);
+
+		if (error == 0) {
+			uio.uio_iov = &iov;
+			uio.uio_iovcnt = 1;
+			iov.iov_base = buf;
+			iov.iov_len = MAXBSIZE - uio.uio_resid;
+			uio.uio_offset = offset;
+			uio.uio_rw = UIO_WRITE;
+			uio.uio_resid = iov.iov_len;
+
+			if (uio.uio_resid == 0)
+				break;
+
+			do {
+				error = VOP_WRITE(tvp, &uio, 0, cred);
+			} while ((uio.uio_resid > 0) && (error == 0));
+		}
+
+	} while (error == 0);
+
+	free(buf, M_TEMP);
+	return (error);
+}
+
+/*
+ * Create a shadow directory in the upper layer.
+ * The new vnode is returned locked.
+ *
+ * (um) points to the union mount structure for access to the
+ * the mounting process's credentials.
+ * (dvp) is the directory in which to create the shadow directory.
+ * it is unlocked on entry and exit.
+ * (cnp) is the componentname to be created.
+ * (vpp) is the returned newly created shadow directory, which
+ * is returned locked.
+ */
+int
+union_mkshadow(um, dvp, cnp, vpp)
+	struct union_mount *um;
+	struct vnode *dvp;
+	struct componentname *cnp;
+	struct vnode **vpp;
+{
+	int error;
+	struct vattr va;
+	struct proc *p = cnp->cn_proc;
+	struct componentname cn;
+
+	/*
+	 * policy: when creating the shadow directory in the
+	 * upper layer, create it owned by the user who did
+	 * the mount, group from parent directory, and mode
+	 * 777 modified by umask (ie mostly identical to the
+	 * mkdir syscall).  (jsp, kb)
+	 */
+
+	/*
+	 * A new componentname structure must be faked up because
+	 * there is no way to know where the upper level cnp came
+	 * from or what it is being used for.  This must duplicate
+	 * some of the work done by NDINIT, some of the work done
+	 * by namei, some of the work done by lookup and some of
+	 * the work done by VOP_LOOKUP when given a CREATE flag.
+	 * Conclusion: Horrible.
+	 *
+	 * The pathname buffer will be FREEed by VOP_MKDIR.
+	 */
+	cn.cn_pnbuf = malloc(cnp->cn_namelen+1, M_NAMEI, M_WAITOK);
+	bcopy(cnp->cn_nameptr, cn.cn_pnbuf, cnp->cn_namelen);
+	cn.cn_pnbuf[cnp->cn_namelen] = '\0';
+
+	cn.cn_nameiop = CREATE;
+	cn.cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN);
+	cn.cn_proc = cnp->cn_proc;
+	if (um->um_op == UNMNT_ABOVE)
+		cn.cn_cred = cnp->cn_cred;
+	else
+		cn.cn_cred = um->um_cred;
+	cn.cn_nameptr = cn.cn_pnbuf;
+	cn.cn_namelen = cnp->cn_namelen;
+	cn.cn_hash = cnp->cn_hash;
+	cn.cn_consume = cnp->cn_consume;
+
+	VREF(dvp);
+	if (error = relookup(dvp, vpp, &cn))
+		return (error);
+	vrele(dvp);
+
+	if (*vpp) {
+		VOP_ABORTOP(dvp, &cn);
+		VOP_UNLOCK(dvp);
+		vrele(*vpp);
+		*vpp = NULLVP;
+		return (EEXIST);
+	}
+
+	VATTR_NULL(&va);
+	va.va_type = VDIR;
+	va.va_mode = um->um_cmode;
+
+	/* LEASE_CHECK: dvp is locked */
+	LEASE_CHECK(dvp, p, p->p_ucred, LEASE_WRITE);
+
+	error = VOP_MKDIR(dvp, vpp, &cn, &va);
+	return (error);
+}
+
+/*
+ * union_vn_create: creates and opens a new shadow file
+ * on the upper union layer.  this function is similar
+ * in spirit to calling vn_open but it avoids calling namei().
+ * the problem with calling namei is that a) it locks too many
+ * things, and b) it doesn't start at the "right" directory,
+ * whereas relookup is told where to start.
+ */
+int
+union_vn_create(vpp, un, p)
+	struct vnode **vpp;
+	struct union_node *un;
+	struct proc *p;
+{
+	struct vnode *vp;
+	struct ucred *cred = p->p_ucred;
+	struct vattr vat;
+	struct vattr *vap = &vat;
+	int fmode = FFLAGS(O_WRONLY|O_CREAT|O_TRUNC|O_EXCL);
+	int error;
+	int cmode = UN_FILEMODE & ~p->p_fd->fd_cmask;
+	char *cp;
+	struct componentname cn;
+
+	*vpp = NULLVP;
+
+	/*
+	 * Build a new componentname structure (for the same
+	 * reasons outlines in union_mkshadow).
+	 * The difference here is that the file is owned by
+	 * the current user, rather than by the person who
+	 * did the mount, since the current user needs to be
+	 * able to write the file (that's why it is being
+	 * copied in the first place).
+	 */
+	cn.cn_namelen = strlen(un->un_path);
+	cn.cn_pnbuf = (caddr_t) malloc(cn.cn_namelen, M_NAMEI, M_WAITOK);
+	bcopy(un->un_path, cn.cn_pnbuf, cn.cn_namelen+1);
+	cn.cn_nameiop = CREATE;
+	cn.cn_flags = (LOCKPARENT|HASBUF|SAVENAME|SAVESTART|ISLASTCN);
+	cn.cn_proc = p;
+	cn.cn_cred = p->p_ucred;
+	cn.cn_nameptr = cn.cn_pnbuf;
+	cn.cn_hash = un->un_hash;
+	cn.cn_consume = 0;
+
+	VREF(un->un_dirvp);
+	if (error = relookup(un->un_dirvp, &vp, &cn))
+		return (error);
+	vrele(un->un_dirvp);
+
+	if (vp) {
+		VOP_ABORTOP(un->un_dirvp, &cn);
+		if (un->un_dirvp == vp)
+			vrele(un->un_dirvp);
+		else
+			vput(un->un_dirvp);
+		vrele(vp);
+		return (EEXIST);
+	}
+
+	/*
+	 * Good - there was no race to create the file
+	 * so go ahead and create it.  The permissions
+	 * on the file will be 0666 modified by the
+	 * current user's umask.  Access to the file, while
+	 * it is unioned, will require access to the top *and*
+	 * bottom files.  Access when not unioned will simply
+	 * require access to the top-level file.
+	 * TODO: confirm choice of access permissions.
+	 */
+	VATTR_NULL(vap);
+	vap->va_type = VREG;
+	vap->va_mode = cmode;
+	LEASE_CHECK(un->un_dirvp, p, cred, LEASE_WRITE);
+	if (error = VOP_CREATE(un->un_dirvp, &vp, &cn, vap))
+		return (error);
+
+	if (error = VOP_OPEN(vp, fmode, cred, p)) {
+		vput(vp);
+		return (error);
+	}
+
+	vp->v_writecount++;
+	*vpp = vp;
+	return (0);
+}
+
+int
+union_vn_close(vp, fmode, cred, p)
+	struct vnode *vp;
+	int fmode;
+	struct ucred *cred;
+	struct proc *p;
+{
+	if (fmode & FWRITE)
+		--vp->v_writecount;
+	return (VOP_CLOSE(vp, fmode));
+}
+
+void
+union_removed_upper(un)
+	struct union_node *un;
+{
+	if (un->un_flags & UN_ULOCK) {
+		un->un_flags &= ~UN_ULOCK;
+		VOP_UNLOCK(un->un_uppervp);
+	}
+
+	union_newupper(un, NULLVP);
+}
+
+struct vnode *
+union_lowervp(vp)
+	struct vnode *vp;
+{
+	struct union_node *un = VTOUNION(vp);
+
+	if (un->un_lowervp && (vp->v_type == un->un_lowervp->v_type)) {
+		if (vget(un->un_lowervp, 0))
+			return (NULLVP);
+	}
+
+	return (un->un_lowervp);
+}
diff --git a/sys/miscfs/union/union_vfsops.c b/sys/miscfs/union/union_vfsops.c
new file mode 100644
index 0000000..9fa2746
--- /dev/null
+++ b/sys/miscfs/union/union_vfsops.c
@@ -0,0 +1,550 @@
+/*
+ * Copyright (c) 1994 The Regents of the University of California.
+ * Copyright (c) 1994 Jan-Simon Pendry.
+ * All rights reserved.
+ *
+ * This code is derived from software donated to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)union_vfsops.c	8.7 (Berkeley) 3/5/94
+ */
+
+/*
+ * Union Layer
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/proc.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/filedesc.h>
+#include <sys/queue.h>
+#include <miscfs/union/union.h>
+
+/*
+ * Mount union filesystem
+ */
+int
+union_mount(mp, path, data, ndp, p)
+	struct mount *mp;
+	char *path;
+	caddr_t data;
+	struct nameidata *ndp;
+	struct proc *p;
+{
+	int error = 0;
+	struct union_args args;
+	struct vnode *lowerrootvp = NULLVP;
+	struct vnode *upperrootvp = NULLVP;
+	struct union_mount *um;
+	struct ucred *cred = 0;
+	struct ucred *scred;
+	struct vattr va;
+	char *cp;
+	int len;
+	u_int size;
+
+#ifdef UNION_DIAGNOSTIC
+	printf("union_mount(mp = %x)\n", mp);
+#endif
+
+	/*
+	 * Update is a no-op
+	 */
+	if (mp->mnt_flag & MNT_UPDATE) {
+		/*
+		 * Need to provide.
+		 * 1. a way to convert between rdonly and rdwr mounts.
+		 * 2. support for nfs exports.
+		 */
+		error = EOPNOTSUPP;
+		goto bad;
+	}
+
+	/*
+	 * Take a copy of the process's credentials.  This isn't
+	 * quite right since the euid will always be zero and we
+	 * want to get the "real" users credentials.  So fix up
+	 * the uid field after taking the copy.
+	 */
+	cred = crdup(p->p_ucred);
+	cred->cr_uid = p->p_cred->p_ruid;
+
+	/*
+	 * Ensure the *real* user has write permission on the
+	 * mounted-on directory.  This allows the mount_union
+	 * command to be made setuid root so allowing anyone
+	 * to do union mounts onto any directory on which they
+	 * have write permission and which they also own.
+	 */
+	error = VOP_GETATTR(mp->mnt_vnodecovered, &va, cred, p);
+	if (error)
+		goto bad;
+	if ((va.va_uid != cred->cr_uid) && 
+	    (cred->cr_uid != 0)) {
+		error = EACCES;
+		goto bad;
+	}
+	error = VOP_ACCESS(mp->mnt_vnodecovered, VWRITE, cred, p);
+	if (error)
+		goto bad;
+
+	/*
+	 * Get argument
+	 */
+	if (error = copyin(data, (caddr_t)&args, sizeof(struct union_args)))
+		goto bad;
+
+	lowerrootvp = mp->mnt_vnodecovered;
+	VREF(lowerrootvp);
+
+	/*
+	 * Find upper node.  Use the real process credentials,
+	 * not the effective ones since this will have come
+	 * through a setuid process (mount_union).  All this
+	 * messing around with permissions is entirely bogus
+	 * and should be removed by allowing any user straight
+	 * past the mount system call.
+	 */
+	scred = p->p_ucred;
+	p->p_ucred = cred;
+	NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT,
+	       UIO_USERSPACE, args.target, p);
+	p->p_ucred = scred;
+
+	if (error = namei(ndp))
+		goto bad;
+
+	upperrootvp = ndp->ni_vp;
+	vrele(ndp->ni_dvp);
+	ndp->ni_dvp = NULL;
+
+	if (upperrootvp->v_type != VDIR) {
+		error = EINVAL;
+		goto bad;
+	}
+	
+	um = (struct union_mount *) malloc(sizeof(struct union_mount),
+				M_UFSMNT, M_WAITOK);	/* XXX */
+
+	/*
+	 * Keep a held reference to the target vnodes.
+	 * They are vrele'd in union_unmount.
+	 *
+	 * Depending on the _BELOW flag, the filesystems are
+	 * viewed in a different order.  In effect, this is the
+	 * same as providing a mount under option to the mount syscall.
+	 */
+
+	um->um_op = args.mntflags & UNMNT_OPMASK;
+	switch (um->um_op) {
+	case UNMNT_ABOVE:
+		um->um_lowervp = lowerrootvp;
+		um->um_uppervp = upperrootvp;
+		break;
+
+	case UNMNT_BELOW:
+		um->um_lowervp = upperrootvp;
+		um->um_uppervp = lowerrootvp;
+		break;
+
+	case UNMNT_REPLACE:
+		vrele(lowerrootvp);
+		lowerrootvp = NULLVP;
+		um->um_uppervp = upperrootvp;
+		um->um_lowervp = lowerrootvp;
+		break;
+
+	default:
+		error = EINVAL;
+		goto bad;
+	}
+
+	um->um_cred = cred;
+	um->um_cmode = UN_DIRMODE &~ p->p_fd->fd_cmask;
+
+	/*
+	 * Depending on what you think the MNT_LOCAL flag might mean,
+	 * you may want the && to be || on the conditional below.
+	 * At the moment it has been defined that the filesystem is
+	 * only local if it is all local, ie the MNT_LOCAL flag implies
+	 * that the entire namespace is local.  If you think the MNT_LOCAL
+	 * flag implies that some of the files might be stored locally
+	 * then you will want to change the conditional.
+	 */
+	if (um->um_op == UNMNT_ABOVE) {
+		if (((um->um_lowervp == NULLVP) ||
+		     (um->um_lowervp->v_mount->mnt_flag & MNT_LOCAL)) &&
+		    (um->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
+			mp->mnt_flag |= MNT_LOCAL;
+	}
+
+	/*
+	 * Copy in the upper layer's RDONLY flag.  This is for the benefit
+	 * of lookup() which explicitly checks the flag, rather than asking
+	 * the filesystem for it's own opinion.  This means, that an update
+	 * mount of the underlying filesystem to go from rdonly to rdwr
+	 * will leave the unioned view as read-only.
+	 */
+	mp->mnt_flag |= (um->um_uppervp->v_mount->mnt_flag & MNT_RDONLY);
+
+	/*
+	 * This is a user mount.  Privilege check for unmount
+	 * will be done in union_unmount.
+	 */
+	mp->mnt_flag |= MNT_USER;
+
+	mp->mnt_data = (qaddr_t) um;
+	getnewfsid(mp, MOUNT_UNION);
+
+	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
+	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
+
+	switch (um->um_op) {
+	case UNMNT_ABOVE:
+		cp = "<above>";
+		break;
+	case UNMNT_BELOW:
+		cp = "<below>";
+		break;
+	case UNMNT_REPLACE:
+		cp = "";
+		break;
+	}
+	len = strlen(cp);
+	bcopy(cp, mp->mnt_stat.f_mntfromname, len);
+
+	cp = mp->mnt_stat.f_mntfromname + len;
+	len = MNAMELEN - len;
+
+	(void) copyinstr(args.target, cp, len - 1, &size);
+	bzero(cp + size, len - size);
+
+#ifdef UNION_DIAGNOSTIC
+	printf("union_mount: from %s, on %s\n",
+		mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
+#endif
+	return (0);
+
+bad:
+	if (cred)
+		crfree(cred);
+	if (upperrootvp)
+		vrele(upperrootvp);
+	if (lowerrootvp)
+		vrele(lowerrootvp);
+	return (error);
+}
+
+/*
+ * VFS start.  Nothing needed here - the start routine
+ * on the underlying filesystem(s) will have been called
+ * when that filesystem was mounted.
+ */
+int
+union_start(mp, flags, p)
+	struct mount *mp;
+	int flags;
+	struct proc *p;
+{
+
+	return (0);
+}
+
+/*
+ * Free reference to union layer
+ */
+int
+union_unmount(mp, mntflags, p)
+	struct mount *mp;
+	int mntflags;
+	struct proc *p;
+{
+	struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
+	struct vnode *um_rootvp;
+	int error;
+	int flags = 0;
+	extern int doforce;
+
+#ifdef UNION_DIAGNOSTIC
+	printf("union_unmount(mp = %x)\n", mp);
+#endif
+
+	/* only the mounter, or superuser can unmount */
+	if ((p->p_cred->p_ruid != um->um_cred->cr_uid) &&
+	    (error = suser(p->p_ucred, &p->p_acflag)))
+		return (error);
+
+	if (mntflags & MNT_FORCE) {
+		/* union can never be rootfs so don't check for it */
+		if (!doforce)
+			return (EINVAL);
+		flags |= FORCECLOSE;
+	}
+
+	if (error = union_root(mp, &um_rootvp))
+		return (error);
+	if (um_rootvp->v_usecount > 1) {
+		vput(um_rootvp);
+		return (EBUSY);
+	}
+	if (error = vflush(mp, um_rootvp, flags)) {
+		vput(um_rootvp);
+		return (error);
+	}
+
+#ifdef UNION_DIAGNOSTIC
+	vprint("alias root of lower", um_rootvp);
+#endif	 
+	/*
+	 * Discard references to upper and lower target vnodes.
+	 */
+	if (um->um_lowervp)
+		vrele(um->um_lowervp);
+	vrele(um->um_uppervp);
+	crfree(um->um_cred);
+	/*
+	 * Release reference on underlying root vnode
+	 */
+	vput(um_rootvp);
+	/*
+	 * And blow it away for future re-use
+	 */
+	vgone(um_rootvp);
+	/*
+	 * Finally, throw away the union_mount structure
+	 */
+	free(mp->mnt_data, M_UFSMNT);	/* XXX */
+	mp->mnt_data = 0;
+	return (0);
+}
+
+int
+union_root(mp, vpp)
+	struct mount *mp;
+	struct vnode **vpp;
+{
+	struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
+	int error;
+	int loselock;
+
+#ifdef UNION_DIAGNOSTIC
+	printf("union_root(mp = %x, lvp = %x, uvp = %x)\n", mp,
+			um->um_lowervp,
+			um->um_uppervp);
+#endif
+
+	/*
+	 * Return locked reference to root.
+	 */
+	VREF(um->um_uppervp);
+	if ((um->um_op == UNMNT_BELOW) &&
+	     VOP_ISLOCKED(um->um_uppervp)) {
+		loselock = 1;
+	} else {
+		VOP_LOCK(um->um_uppervp);
+		loselock = 0;
+	}
+	if (um->um_lowervp)
+		VREF(um->um_lowervp);
+	error = union_allocvp(vpp, mp,
+			      (struct vnode *) 0,
+			      (struct vnode *) 0,
+			      (struct componentname *) 0,
+			      um->um_uppervp,
+			      um->um_lowervp);
+
+	if (error) {
+		if (!loselock)
+			VOP_UNLOCK(um->um_uppervp);
+		vrele(um->um_uppervp);
+		if (um->um_lowervp)
+			vrele(um->um_lowervp);
+	} else {
+		(*vpp)->v_flag |= VROOT;
+		if (loselock)
+			VTOUNION(*vpp)->un_flags &= ~UN_ULOCK;
+	}
+
+	return (error);
+}
+
+int
+union_quotactl(mp, cmd, uid, arg, p)
+	struct mount *mp;
+	int cmd;
+	uid_t uid;
+	caddr_t arg;
+	struct proc *p;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+union_statfs(mp, sbp, p)
+	struct mount *mp;
+	struct statfs *sbp;
+	struct proc *p;
+{
+	int error;
+	struct union_mount *um = MOUNTTOUNIONMOUNT(mp);
+	struct statfs mstat;
+	int lbsize;
+
+#ifdef UNION_DIAGNOSTIC
+	printf("union_statfs(mp = %x, lvp = %x, uvp = %x)\n", mp,
+			um->um_lowervp,
+	       		um->um_uppervp);
+#endif
+
+	bzero(&mstat, sizeof(mstat));
+
+	if (um->um_lowervp) {
+		error = VFS_STATFS(um->um_lowervp->v_mount, &mstat, p);
+		if (error)
+			return (error);
+	}
+
+	/* now copy across the "interesting" information and fake the rest */
+#if 0
+	sbp->f_type = mstat.f_type;
+	sbp->f_flags = mstat.f_flags;
+	sbp->f_bsize = mstat.f_bsize;
+	sbp->f_iosize = mstat.f_iosize;
+#endif
+	lbsize = mstat.f_bsize;
+	sbp->f_blocks = mstat.f_blocks;
+	sbp->f_bfree = mstat.f_bfree;
+	sbp->f_bavail = mstat.f_bavail;
+	sbp->f_files = mstat.f_files;
+	sbp->f_ffree = mstat.f_ffree;
+
+	error = VFS_STATFS(um->um_uppervp->v_mount, &mstat, p);
+	if (error)
+		return (error);
+
+	sbp->f_type = MOUNT_UNION;
+	sbp->f_flags = mstat.f_flags;
+	sbp->f_bsize = mstat.f_bsize;
+	sbp->f_iosize = mstat.f_iosize;
+
+	/*
+	 * if the lower and upper blocksizes differ, then frig the
+	 * block counts so that the sizes reported by df make some
+	 * kind of sense.  none of this makes sense though.
+	 */
+
+	if (mstat.f_bsize != lbsize) {
+		sbp->f_blocks = sbp->f_blocks * lbsize / mstat.f_bsize;
+		sbp->f_bfree = sbp->f_bfree * lbsize / mstat.f_bsize;
+		sbp->f_bavail = sbp->f_bavail * lbsize / mstat.f_bsize;
+	}
+	sbp->f_blocks += mstat.f_blocks;
+	sbp->f_bfree += mstat.f_bfree;
+	sbp->f_bavail += mstat.f_bavail;
+	sbp->f_files += mstat.f_files;
+	sbp->f_ffree += mstat.f_ffree;
+
+	if (sbp != &mp->mnt_stat) {
+		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
+		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
+		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
+	}
+	return (0);
+}
+
+int
+union_sync(mp, waitfor, cred, p)
+	struct mount *mp;
+	int waitfor;
+	struct ucred *cred;
+	struct proc *p;
+{
+
+	/*
+	 * XXX - Assumes no data cached at union layer.
+	 */
+	return (0);
+}
+
+int
+union_vget(mp, ino, vpp)
+	struct mount *mp;
+	ino_t ino;
+	struct vnode **vpp;
+{
+	
+	return (EOPNOTSUPP);
+}
+
+int
+union_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp)
+	struct mount *mp;
+	struct fid *fidp;
+	struct mbuf *nam;
+	struct vnode **vpp;
+	int *exflagsp;
+	struct ucred **credanonp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int
+union_vptofh(vp, fhp)
+	struct vnode *vp;
+	struct fid *fhp;
+{
+
+	return (EOPNOTSUPP);
+}
+
+int union_init __P((void));
+
+struct vfsops union_vfsops = {
+	union_mount,
+	union_start,
+	union_unmount,
+	union_root,
+	union_quotactl,
+	union_statfs,
+	union_sync,
+	union_vget,
+	union_fhtovp,
+	union_vptofh,
+	union_init,
+};
diff --git a/sys/miscfs/union/union_vnops.c b/sys/miscfs/union/union_vnops.c
new file mode 100644
index 0000000..96327b0
--- /dev/null
+++ b/sys/miscfs/union/union_vnops.c
@@ -0,0 +1,1495 @@
+/*
+ * Copyright (c) 1992, 1993, 1994 The Regents of the University of California.
+ * Copyright (c) 1992, 1993, 1994 Jan-Simon Pendry.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Jan-Simon Pendry.
+ *
+ * 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.
+ *
+ *	@(#)union_vnops.c	8.6 (Berkeley) 2/17/94
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/file.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/vnode.h>
+#include <sys/mount.h>
+#include <sys/namei.h>
+#include <sys/malloc.h>
+#include <sys/buf.h>
+#include <sys/queue.h>
+#include <miscfs/union/union.h>
+
+#define FIXUP(un) { \
+	if (((un)->un_flags & UN_ULOCK) == 0) { \
+		union_fixup(un); \
+	} \
+}
+
+static void
+union_fixup(un)
+	struct union_node *un;
+{
+
+	VOP_LOCK(un->un_uppervp);
+	un->un_flags |= UN_ULOCK;
+}
+
+static int
+union_lookup1(udvp, dvp, vpp, cnp)
+	struct vnode *udvp;
+	struct vnode *dvp;
+	struct vnode **vpp;
+	struct componentname *cnp;
+{
+	int error;
+	struct vnode *tdvp;
+	struct mount *mp;
+
+	/*
+	 * If stepping up the directory tree, check for going
+	 * back across the mount point, in which case do what
+	 * lookup would do by stepping back down the mount
+	 * hierarchy.
+	 */
+	if (cnp->cn_flags & ISDOTDOT) {
+		for (;;) {
+			/*
+			 * Don't do the NOCROSSMOUNT check
+			 * at this level.  By definition,
+			 * union fs deals with namespaces, not
+			 * filesystems.
+			 */
+			if ((dvp->v_flag & VROOT) == 0)
+				break;
+
+			tdvp = dvp;
+			dvp = dvp->v_mount->mnt_vnodecovered;
+			vput(tdvp);
+			VREF(dvp);
+			VOP_LOCK(dvp);
+		}
+	}
+
+        error = VOP_LOOKUP(dvp, &tdvp, cnp);
+	if (error)
+		return (error);
+
+	/*
+	 * The parent directory will have been unlocked, unless lookup
+	 * found the last component.  In which case, re-lock the node
+	 * here to allow it to be unlocked again (phew) in union_lookup.
+	 */
+	if (dvp != tdvp && !(cnp->cn_flags & ISLASTCN))
+		VOP_LOCK(dvp);
+
+	dvp = tdvp;
+
+	/*
+	 * Lastly check if the current node is a mount point in
+	 * which case walk up the mount hierarchy making sure not to
+	 * bump into the root of the mount tree (ie. dvp != udvp).
+	 */
+	while (dvp != udvp && (dvp->v_type == VDIR) &&
+	       (mp = dvp->v_mountedhere)) {
+
+		if (mp->mnt_flag & MNT_MLOCK) {
+			mp->mnt_flag |= MNT_MWAIT;
+			sleep((caddr_t) mp, PVFS);
+			continue;
+		}
+
+		if (error = VFS_ROOT(mp, &tdvp)) {
+			vput(dvp);
+			return (error);
+		}
+
+		vput(dvp);
+		dvp = tdvp;
+	}
+
+	*vpp = dvp;
+	return (0);
+}
+
+int
+union_lookup(ap)
+	struct vop_lookup_args /* {
+		struct vnodeop_desc *a_desc;
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+	int error;
+	int uerror, lerror;
+	struct vnode *uppervp, *lowervp;
+	struct vnode *upperdvp, *lowerdvp;
+	struct vnode *dvp = ap->a_dvp;
+	struct union_node *dun = VTOUNION(dvp);
+	struct componentname *cnp = ap->a_cnp;
+	int lockparent = cnp->cn_flags & LOCKPARENT;
+	int rdonly = cnp->cn_flags & RDONLY;
+	struct union_mount *um = MOUNTTOUNIONMOUNT(dvp->v_mount);
+	struct ucred *saved_cred;
+
+	cnp->cn_flags |= LOCKPARENT;
+
+	upperdvp = dun->un_uppervp;
+	lowerdvp = dun->un_lowervp;
+	uppervp = NULLVP;
+	lowervp = NULLVP;
+
+	/*
+	 * do the lookup in the upper level.
+	 * if that level comsumes additional pathnames,
+	 * then assume that something special is going
+	 * on and just return that vnode.
+	 */
+	if (upperdvp) {
+		FIXUP(dun);
+		uerror = union_lookup1(um->um_uppervp, upperdvp,
+					&uppervp, cnp);
+		/*if (uppervp == upperdvp)
+			dun->un_flags |= UN_KLOCK;*/
+
+		if (cnp->cn_consume != 0) {
+			*ap->a_vpp = uppervp;
+			if (!lockparent)
+				cnp->cn_flags &= ~LOCKPARENT;
+			return (uerror);
+		}
+	} else {
+		uerror = ENOENT;
+	}
+
+	/*
+	 * in a similar way to the upper layer, do the lookup
+	 * in the lower layer.   this time, if there is some
+	 * component magic going on, then vput whatever we got
+	 * back from the upper layer and return the lower vnode
+	 * instead.
+	 */
+	if (lowerdvp) {
+		int nameiop;
+
+		VOP_LOCK(lowerdvp);
+
+		/*
+		 * Only do a LOOKUP on the bottom node, since
+		 * we won't be making changes to it anyway.
+		 */
+		nameiop = cnp->cn_nameiop;
+		cnp->cn_nameiop = LOOKUP;
+		if (um->um_op == UNMNT_BELOW) {
+			saved_cred = cnp->cn_cred;
+			cnp->cn_cred = um->um_cred;
+		}
+		lerror = union_lookup1(um->um_lowervp, lowerdvp,
+				&lowervp, cnp);
+		if (um->um_op == UNMNT_BELOW)
+			cnp->cn_cred = saved_cred;
+		cnp->cn_nameiop = nameiop;
+
+		if (lowervp != lowerdvp)
+			VOP_UNLOCK(lowerdvp);
+
+		if (cnp->cn_consume != 0) {
+			if (uppervp) {
+				if (uppervp == upperdvp)
+					vrele(uppervp);
+				else
+					vput(uppervp);
+				uppervp = NULLVP;
+			}
+			*ap->a_vpp = lowervp;
+			if (!lockparent)
+				cnp->cn_flags &= ~LOCKPARENT;
+			return (lerror);
+		}
+	} else {
+		lerror = ENOENT;
+	}
+
+	if (!lockparent)
+		cnp->cn_flags &= ~LOCKPARENT;
+
+	/*
+	 * at this point, we have uerror and lerror indicating
+	 * possible errors with the lookups in the upper and lower
+	 * layers.  additionally, uppervp and lowervp are (locked)
+	 * references to existing vnodes in the upper and lower layers.
+	 *
+	 * there are now three cases to consider.
+	 * 1. if both layers returned an error, then return whatever
+	 *    error the upper layer generated.
+	 *
+	 * 2. if the top layer failed and the bottom layer succeeded
+	 *    then two subcases occur.
+	 *    a.  the bottom vnode is not a directory, in which
+	 *	  case just return a new union vnode referencing
+	 *	  an empty top layer and the existing bottom layer.
+	 *    b.  the bottom vnode is a directory, in which case
+	 *	  create a new directory in the top-level and
+	 *	  continue as in case 3.
+	 *
+	 * 3. if the top layer succeeded then return a new union
+	 *    vnode referencing whatever the new top layer and
+	 *    whatever the bottom layer returned.
+	 */
+
+	*ap->a_vpp = NULLVP;
+
+	/* case 1. */
+	if ((uerror != 0) && (lerror != 0)) {
+		return (uerror);
+	}
+
+	/* case 2. */
+	if (uerror != 0 /* && (lerror == 0) */ ) {
+		if (lowervp->v_type == VDIR) { /* case 2b. */
+			dun->un_flags &= ~UN_ULOCK;
+			VOP_UNLOCK(upperdvp);
+			uerror = union_mkshadow(um, upperdvp, cnp, &uppervp);
+			VOP_LOCK(upperdvp);
+			dun->un_flags |= UN_ULOCK;
+
+			if (uerror) {
+				if (lowervp) {
+					vput(lowervp);
+					lowervp = NULLVP;
+				}
+				return (uerror);
+			}
+		}
+	}
+
+	if (lowervp)
+		VOP_UNLOCK(lowervp);
+
+	error = union_allocvp(ap->a_vpp, dvp->v_mount, dvp, upperdvp, cnp,
+			      uppervp, lowervp);
+
+	if (error) {
+		if (uppervp)
+			vput(uppervp);
+		if (lowervp)
+			vrele(lowervp);
+	} else {
+		if (*ap->a_vpp != dvp)
+			if (!lockparent || !(cnp->cn_flags & ISLASTCN))
+				VOP_UNLOCK(dvp);
+	}
+
+	return (error);
+}
+
+int
+union_create(ap)
+	struct vop_create_args /* {
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+		struct vattr *a_vap;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_dvp);
+	struct vnode *dvp = un->un_uppervp;
+
+	if (dvp) {
+		int error;
+		struct vnode *vp;
+
+		FIXUP(un);
+
+		VREF(dvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		error = VOP_CREATE(dvp, &vp, ap->a_cnp, ap->a_vap);
+		if (error)
+			return (error);
+
+		error = union_allocvp(
+				ap->a_vpp,
+				ap->a_dvp->v_mount,
+				ap->a_dvp,
+				NULLVP,
+				ap->a_cnp,
+				vp,
+				NULLVP);
+		if (error)
+			vput(vp);
+		return (error);
+	}
+
+	vput(ap->a_dvp);
+	return (EROFS);
+}
+
+int
+union_mknod(ap)
+	struct vop_mknod_args /* {
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+		struct vattr *a_vap;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_dvp);
+	struct vnode *dvp = un->un_uppervp;
+
+	if (dvp) {
+		int error;
+		struct vnode *vp;
+
+		FIXUP(un);
+
+		VREF(dvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		error = VOP_MKNOD(dvp, &vp, ap->a_cnp, ap->a_vap);
+		if (error)
+			return (error);
+
+		if (vp) {
+			error = union_allocvp(
+					ap->a_vpp,
+					ap->a_dvp->v_mount,
+					ap->a_dvp,
+					NULLVP,
+					ap->a_cnp,
+					vp,
+					NULLVP);
+			if (error)
+				vput(vp);
+		}
+		return (error);
+	}
+
+	vput(ap->a_dvp);
+	return (EROFS);
+}
+
+int
+union_open(ap)
+	struct vop_open_args /* {
+		struct vnodeop_desc *a_desc;
+		struct vnode *a_vp;
+		int a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_vp);
+	struct vnode *tvp;
+	int mode = ap->a_mode;
+	struct ucred *cred = ap->a_cred;
+	struct proc *p = ap->a_p;
+	int error;
+
+	/*
+	 * If there is an existing upper vp then simply open that.
+	 */
+	tvp = un->un_uppervp;
+	if (tvp == NULLVP) {
+		/*
+		 * If the lower vnode is being opened for writing, then
+		 * copy the file contents to the upper vnode and open that,
+		 * otherwise can simply open the lower vnode.
+		 */
+		tvp = un->un_lowervp;
+		if ((ap->a_mode & FWRITE) && (tvp->v_type == VREG)) {
+			struct vnode *vp;
+			int i;
+
+			/*
+			 * Open the named file in the upper layer.  Note that
+			 * the file may have come into existence *since* the
+			 * lookup was done, since the upper layer may really
+			 * be a loopback mount of some other filesystem...
+			 * so open the file with exclusive create and barf if
+			 * it already exists.
+			 * XXX - perhaps should re-lookup the node (once more
+			 * with feeling) and simply open that.  Who knows.
+			 */
+			error = union_vn_create(&vp, un, p);
+			if (error)
+				return (error);
+
+			/* at this point, uppervp is locked */
+			union_newupper(un, vp);
+			un->un_flags |= UN_ULOCK;
+
+			/*
+			 * Now, if the file is being opened with truncation,
+			 * then the (new) upper vnode is ready to fly,
+			 * otherwise the data from the lower vnode must be
+			 * copied to the upper layer first.  This only works
+			 * for regular files (check is made above).
+			 */
+			if ((mode & O_TRUNC) == 0) {
+				/*
+				 * XXX - should not ignore errors
+				 * from VOP_CLOSE
+				 */
+				VOP_LOCK(tvp);
+				error = VOP_OPEN(tvp, FREAD, cred, p);
+				if (error == 0) {
+					error = union_copyfile(p, cred,
+						       tvp, un->un_uppervp);
+					VOP_UNLOCK(tvp);
+					(void) VOP_CLOSE(tvp, FREAD);
+				} else {
+					VOP_UNLOCK(tvp);
+				}
+
+#ifdef UNION_DIAGNOSTIC
+				if (!error)
+					uprintf("union: copied up %s\n",
+								un->un_path);
+#endif
+			}
+
+			un->un_flags &= ~UN_ULOCK;
+			VOP_UNLOCK(un->un_uppervp);
+			union_vn_close(un->un_uppervp, FWRITE, cred, p);
+			VOP_LOCK(un->un_uppervp);
+			un->un_flags |= UN_ULOCK;
+
+			/*
+			 * Subsequent IOs will go to the top layer, so
+			 * call close on the lower vnode and open on the
+			 * upper vnode to ensure that the filesystem keeps
+			 * its references counts right.  This doesn't do
+			 * the right thing with (cred) and (FREAD) though.
+			 * Ignoring error returns is not righ, either.
+			 */
+			for (i = 0; i < un->un_openl; i++) {
+				(void) VOP_CLOSE(tvp, FREAD);
+				(void) VOP_OPEN(un->un_uppervp, FREAD, cred, p);
+			}
+			un->un_openl = 0;
+
+			if (error == 0)
+				error = VOP_OPEN(un->un_uppervp, mode, cred, p);
+			return (error);
+		}
+
+		/*
+		 * Just open the lower vnode
+		 */
+		un->un_openl++;
+		VOP_LOCK(tvp);
+		error = VOP_OPEN(tvp, mode, cred, p);
+		VOP_UNLOCK(tvp);
+
+		return (error);
+	}
+
+	FIXUP(un);
+
+	error = VOP_OPEN(tvp, mode, cred, p);
+
+	return (error);
+}
+
+int
+union_close(ap)
+	struct vop_close_args /* {
+		struct vnode *a_vp;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_vp);
+	struct vnode *vp;
+
+	if (un->un_uppervp) {
+		vp = un->un_uppervp;
+	} else {
+#ifdef UNION_DIAGNOSTIC
+		if (un->un_openl <= 0)
+			panic("union: un_openl cnt");
+#endif
+		--un->un_openl;
+		vp = un->un_lowervp;
+	}
+
+	return (VOP_CLOSE(vp, ap->a_fflag, ap->a_cred, ap->a_p));
+}
+
+/*
+ * Check access permission on the union vnode.
+ * The access check being enforced is to check
+ * against both the underlying vnode, and any
+ * copied vnode.  This ensures that no additional
+ * file permissions are given away simply because
+ * the user caused an implicit file copy.
+ */
+int
+union_access(ap)
+	struct vop_access_args /* {
+		struct vnodeop_desc *a_desc;
+		struct vnode *a_vp;
+		int a_mode;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_vp);
+	int error = EACCES;
+	struct vnode *vp;
+
+	if (vp = un->un_uppervp) {
+		FIXUP(un);
+		return (VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p));
+	}
+
+	if (vp = un->un_lowervp) {
+		VOP_LOCK(vp);
+		error = VOP_ACCESS(vp, ap->a_mode, ap->a_cred, ap->a_p);
+		if (error == 0) {
+			struct union_mount *um = MOUNTTOUNIONMOUNT(vp->v_mount);
+
+			if (um->um_op == UNMNT_BELOW)
+				error = VOP_ACCESS(vp, ap->a_mode,
+						um->um_cred, ap->a_p);
+		}
+		VOP_UNLOCK(vp);
+		if (error)
+			return (error);
+	}
+
+	return (error);
+}
+
+/*
+ *  We handle getattr only to change the fsid.
+ */
+int
+union_getattr(ap)
+	struct vop_getattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	int error;
+	struct union_node *un = VTOUNION(ap->a_vp);
+	struct vnode *vp = un->un_uppervp;
+	struct vattr *vap;
+	struct vattr va;
+
+
+	/*
+	 * Some programs walk the filesystem hierarchy by counting
+	 * links to directories to avoid stat'ing all the time.
+	 * This means the link count on directories needs to be "correct".
+	 * The only way to do that is to call getattr on both layers
+	 * and fix up the link count.  The link count will not necessarily
+	 * be accurate but will be large enough to defeat the tree walkers.
+	 */
+
+	vap = ap->a_vap;
+
+	vp = un->un_uppervp;
+	if (vp != NULLVP) {
+		FIXUP(un);
+		error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
+		if (error)
+			return (error);
+	}
+
+	if (vp == NULLVP) {
+		vp = un->un_lowervp;
+	} else if (vp->v_type == VDIR) {
+		vp = un->un_lowervp;
+		vap = &va;
+	} else {
+		vp = NULLVP;
+	}
+
+	if (vp != NULLVP) {
+		VOP_LOCK(vp);
+		error = VOP_GETATTR(vp, vap, ap->a_cred, ap->a_p);
+		VOP_UNLOCK(vp);
+		if (error)
+			return (error);
+	}
+
+	if ((vap != ap->a_vap) && (vap->va_type == VDIR))
+		ap->a_vap->va_nlink += vap->va_nlink;
+
+	vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
+	return (0);
+}
+
+int
+union_setattr(ap)
+	struct vop_setattr_args /* {
+		struct vnode *a_vp;
+		struct vattr *a_vap;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_vp);
+	int error;
+
+	/*
+	 * Handle case of truncating lower object to zero size,
+	 * by creating a zero length upper object.  This is to
+	 * handle the case of open with O_TRUNC and O_CREAT.
+	 */
+	if ((un->un_uppervp == NULLVP) &&
+	    /* assert(un->un_lowervp != NULLVP) */
+	    (un->un_lowervp->v_type == VREG) &&
+	    (ap->a_vap->va_size == 0)) {
+		struct vnode *vp;
+
+		error = union_vn_create(&vp, un, ap->a_p);
+		if (error)
+			return (error);
+
+		/* at this point, uppervp is locked */
+		union_newupper(un, vp);
+
+		VOP_UNLOCK(vp);
+		union_vn_close(un->un_uppervp, FWRITE, ap->a_cred, ap->a_p);
+		VOP_LOCK(vp);
+		un->un_flags |= UN_ULOCK;
+	}
+
+	/*
+	 * Try to set attributes in upper layer,
+	 * otherwise return read-only filesystem error.
+	 */
+	if (un->un_uppervp != NULLVP) {
+		FIXUP(un);
+		error = VOP_SETATTR(un->un_uppervp, ap->a_vap,
+					ap->a_cred, ap->a_p);
+	} else {
+		error = EROFS;
+	}
+
+	return (error);
+}
+
+int
+union_read(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_vp);
+	int dolock = (vp == LOWERVP(ap->a_vp));
+
+	if (dolock)
+		VOP_LOCK(vp);
+	else
+		FIXUP(VTOUNION(ap->a_vp));
+	error = VOP_READ(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
+	if (dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_write(ap)
+	struct vop_read_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		int  a_ioflag;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_vp);
+	int dolock = (vp == LOWERVP(ap->a_vp));
+
+	if (dolock)
+		VOP_LOCK(vp);
+	else
+		FIXUP(VTOUNION(ap->a_vp));
+	error = VOP_WRITE(vp, ap->a_uio, ap->a_ioflag, ap->a_cred);
+	if (dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_ioctl(ap)
+	struct vop_ioctl_args /* {
+		struct vnode *a_vp;
+		int  a_command;
+		caddr_t  a_data;
+		int  a_fflag;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	return (VOP_IOCTL(OTHERVP(ap->a_vp), ap->a_command, ap->a_data,
+				ap->a_fflag, ap->a_cred, ap->a_p));
+}
+
+int
+union_select(ap)
+	struct vop_select_args /* {
+		struct vnode *a_vp;
+		int  a_which;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	return (VOP_SELECT(OTHERVP(ap->a_vp), ap->a_which, ap->a_fflags,
+				ap->a_cred, ap->a_p));
+}
+
+int
+union_mmap(ap)
+	struct vop_mmap_args /* {
+		struct vnode *a_vp;
+		int  a_fflags;
+		struct ucred *a_cred;
+		struct proc *a_p;
+	} */ *ap;
+{
+
+	return (VOP_MMAP(OTHERVP(ap->a_vp), ap->a_fflags,
+				ap->a_cred, ap->a_p));
+}
+
+int
+union_fsync(ap)
+	struct vop_fsync_args /* {
+		struct vnode *a_vp;
+		struct ucred *a_cred;
+		int  a_waitfor;
+		struct proc *a_p;
+	} */ *ap;
+{
+	int error = 0;
+	struct vnode *targetvp = OTHERVP(ap->a_vp);
+
+	if (targetvp) {
+		int dolock = (targetvp == LOWERVP(ap->a_vp));
+
+		if (dolock)
+			VOP_LOCK(targetvp);
+		else
+			FIXUP(VTOUNION(ap->a_vp));
+		error = VOP_FSYNC(targetvp, ap->a_cred,
+					ap->a_waitfor, ap->a_p);
+		if (dolock)
+			VOP_UNLOCK(targetvp);
+	}
+
+	return (error);
+}
+
+int
+union_seek(ap)
+	struct vop_seek_args /* {
+		struct vnode *a_vp;
+		off_t  a_oldoff;
+		off_t  a_newoff;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+
+	return (VOP_SEEK(OTHERVP(ap->a_vp), ap->a_oldoff, ap->a_newoff, ap->a_cred));
+}
+
+int
+union_remove(ap)
+	struct vop_remove_args /* {
+		struct vnode *a_dvp;
+		struct vnode *a_vp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+	int error;
+	struct union_node *dun = VTOUNION(ap->a_dvp);
+	struct union_node *un = VTOUNION(ap->a_vp);
+
+	if (dun->un_uppervp && un->un_uppervp) {
+		struct vnode *dvp = dun->un_uppervp;
+		struct vnode *vp = un->un_uppervp;
+
+		FIXUP(dun);
+		VREF(dvp);
+		dun->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		FIXUP(un);
+		VREF(vp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_vp);
+
+		error = VOP_REMOVE(dvp, vp, ap->a_cnp);
+		if (!error)
+			union_removed_upper(un);
+
+		/*
+		 * XXX: should create a whiteout here
+		 */
+	} else {
+		/*
+		 * XXX: should create a whiteout here
+		 */
+		vput(ap->a_dvp);
+		vput(ap->a_vp);
+		error = EROFS;
+	}
+
+	return (error);
+}
+
+int
+union_link(ap)
+	struct vop_link_args /* {
+		struct vnode *a_vp;
+		struct vnode *a_tdvp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+	int error;
+	struct union_node *dun = VTOUNION(ap->a_vp);
+	struct union_node *un = VTOUNION(ap->a_tdvp);
+
+	if (dun->un_uppervp && un->un_uppervp) {
+		struct vnode *dvp = dun->un_uppervp;
+		struct vnode *vp = un->un_uppervp;
+
+		FIXUP(dun);
+		VREF(dvp);
+		dun->un_flags |= UN_KLOCK;
+		vput(ap->a_vp);
+		FIXUP(un);
+		VREF(vp);
+		vrele(ap->a_tdvp);
+
+		error = VOP_LINK(dvp, vp, ap->a_cnp);
+	} else {
+		/*
+		 * XXX: need to copy to upper layer
+		 * and do the link there.
+		 */
+		vput(ap->a_vp);
+		vrele(ap->a_tdvp);
+		error = EROFS;
+	}
+
+	return (error);
+}
+
+int
+union_rename(ap)
+	struct vop_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;
+	} */ *ap;
+{
+	int error;
+
+	struct vnode *fdvp = ap->a_fdvp;
+	struct vnode *fvp = ap->a_fvp;
+	struct vnode *tdvp = ap->a_tdvp;
+	struct vnode *tvp = ap->a_tvp;
+
+	if (fdvp->v_op == union_vnodeop_p) {	/* always true */
+		struct union_node *un = VTOUNION(fdvp);
+		if (un->un_uppervp == NULLVP) {
+			error = EROFS;
+			goto bad;
+		}
+
+		FIXUP(un);
+		fdvp = un->un_uppervp;
+		VREF(fdvp);
+		vrele(ap->a_fdvp);
+	}
+
+	if (fvp->v_op == union_vnodeop_p) {	/* always true */
+		struct union_node *un = VTOUNION(fvp);
+		if (un->un_uppervp == NULLVP) {
+			error = EROFS;
+			goto bad;
+		}
+
+		FIXUP(un);
+		fvp = un->un_uppervp;
+		VREF(fvp);
+		vrele(ap->a_fvp);
+	}
+
+	if (tdvp->v_op == union_vnodeop_p) {
+		struct union_node *un = VTOUNION(tdvp);
+		if (un->un_uppervp == NULLVP) {
+			error = EROFS;
+			goto bad;
+		}
+
+		tdvp = un->un_uppervp;
+		VREF(tdvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_tdvp);
+	}
+
+	if (tvp && tvp->v_op == union_vnodeop_p) {
+		struct union_node *un = VTOUNION(tvp);
+		if (un->un_uppervp == NULLVP) {
+			error = EROFS;
+			goto bad;
+		}
+
+		tvp = un->un_uppervp;
+		VREF(tvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_tvp);
+	}
+
+	return (VOP_RENAME(fdvp, fvp, ap->a_fcnp, tdvp, tvp, ap->a_tcnp));
+
+bad:
+	vrele(fdvp);
+	vrele(fvp);
+	vput(tdvp);
+	if (tvp)
+		vput(tvp);
+
+	return (error);
+}
+
+int
+union_mkdir(ap)
+	struct vop_mkdir_args /* {
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+		struct vattr *a_vap;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_dvp);
+	struct vnode *dvp = un->un_uppervp;
+
+	if (dvp) {
+		int error;
+		struct vnode *vp;
+
+		FIXUP(un);
+		VREF(dvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		error = VOP_MKDIR(dvp, &vp, ap->a_cnp, ap->a_vap);
+		if (error)
+			return (error);
+
+		error = union_allocvp(
+				ap->a_vpp,
+				ap->a_dvp->v_mount,
+				ap->a_dvp,
+				NULLVP,
+				ap->a_cnp,
+				vp,
+				NULLVP);
+		if (error)
+			vput(vp);
+		return (error);
+	}
+
+	vput(ap->a_dvp);
+	return (EROFS);
+}
+
+int
+union_rmdir(ap)
+	struct vop_rmdir_args /* {
+		struct vnode *a_dvp;
+		struct vnode *a_vp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+	int error;
+	struct union_node *dun = VTOUNION(ap->a_dvp);
+	struct union_node *un = VTOUNION(ap->a_vp);
+
+	if (dun->un_uppervp && un->un_uppervp) {
+		struct vnode *dvp = dun->un_uppervp;
+		struct vnode *vp = un->un_uppervp;
+
+		FIXUP(dun);
+		VREF(dvp);
+		dun->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		FIXUP(un);
+		VREF(vp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_vp);
+
+		error = VOP_RMDIR(dvp, vp, ap->a_cnp);
+		if (!error)
+			union_removed_upper(un);
+
+		/*
+		 * XXX: should create a whiteout here
+		 */
+	} else {
+		/*
+		 * XXX: should create a whiteout here
+		 */
+		vput(ap->a_dvp);
+		vput(ap->a_vp);
+		error = EROFS;
+	}
+
+	return (error);
+}
+
+int
+union_symlink(ap)
+	struct vop_symlink_args /* {
+		struct vnode *a_dvp;
+		struct vnode **a_vpp;
+		struct componentname *a_cnp;
+		struct vattr *a_vap;
+		char *a_target;
+	} */ *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_dvp);
+	struct vnode *dvp = un->un_uppervp;
+
+	if (dvp) {
+		int error;
+		struct vnode *vp;
+		struct mount *mp = ap->a_dvp->v_mount;
+
+		FIXUP(un);
+		VREF(dvp);
+		un->un_flags |= UN_KLOCK;
+		vput(ap->a_dvp);
+		error = VOP_SYMLINK(dvp, &vp, ap->a_cnp,
+					ap->a_vap, ap->a_target);
+		*ap->a_vpp = NULLVP;
+		return (error);
+	}
+
+	vput(ap->a_dvp);
+	return (EROFS);
+}
+
+/*
+ * union_readdir works in concert with getdirentries and
+ * readdir(3) to provide a list of entries in the unioned
+ * directories.  getdirentries is responsible for walking
+ * down the union stack.  readdir(3) is responsible for
+ * eliminating duplicate names from the returned data stream.
+ */
+int
+union_readdir(ap)
+	struct vop_readdir_args /* {
+		struct vnodeop_desc *a_desc;
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error = 0;
+	struct union_node *un = VTOUNION(ap->a_vp);
+
+	if (un->un_uppervp) {
+		FIXUP(un);
+		error = VOP_READDIR(un->un_uppervp, ap->a_uio, ap->a_cred);
+	}
+
+	return (error);
+}
+
+int
+union_readlink(ap)
+	struct vop_readlink_args /* {
+		struct vnode *a_vp;
+		struct uio *a_uio;
+		struct ucred *a_cred;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_vp);
+	int dolock = (vp == LOWERVP(ap->a_vp));
+
+	if (dolock)
+		VOP_LOCK(vp);
+	else
+		FIXUP(VTOUNION(ap->a_vp));
+	error = VOP_READLINK(vp, ap->a_uio, ap->a_cred);
+	if (dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_abortop(ap)
+	struct vop_abortop_args /* {
+		struct vnode *a_dvp;
+		struct componentname *a_cnp;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_dvp);
+	struct union_node *un = VTOUNION(ap->a_dvp);
+	int islocked = un->un_flags & UN_LOCKED;
+	int dolock = (vp == LOWERVP(ap->a_dvp));
+
+	if (islocked) {
+		if (dolock)
+			VOP_LOCK(vp);
+		else
+			FIXUP(VTOUNION(ap->a_dvp));
+	}
+	error = VOP_ABORTOP(vp, ap->a_cnp);
+	if (islocked && dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_inactive(ap)
+	struct vop_inactive_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	/*
+	 * Do nothing (and _don't_ bypass).
+	 * Wait to vrele lowervp until reclaim,
+	 * so that until then our union_node is in the
+	 * cache and reusable.
+	 *
+	 * NEEDSWORK: Someday, consider inactive'ing
+	 * the lowervp and then trying to reactivate it
+	 * with capabilities (v_id)
+	 * like they do in the name lookup cache code.
+	 * That's too much work for now.
+	 */
+
+#ifdef UNION_DIAGNOSTIC
+	struct union_node *un = VTOUNION(ap->a_vp);
+
+	if (un->un_flags & UN_LOCKED)
+		panic("union: inactivating locked node");
+#endif
+
+	return (0);
+}
+
+int
+union_reclaim(ap)
+	struct vop_reclaim_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	union_freevp(ap->a_vp);
+
+	return (0);
+}
+
+int
+union_lock(ap)
+	struct vop_lock_args *ap;
+{
+	struct vnode *vp = ap->a_vp;
+	struct union_node *un;
+
+start:
+	while (vp->v_flag & VXLOCK) {
+		vp->v_flag |= VXWANT;
+		sleep((caddr_t)vp, PINOD);
+	}
+
+	un = VTOUNION(vp);
+
+	if (un->un_uppervp) {
+		if ((un->un_flags & UN_ULOCK) == 0) {
+			un->un_flags |= UN_ULOCK;
+			VOP_LOCK(un->un_uppervp);
+		}
+#ifdef DIAGNOSTIC
+		if (un->un_flags & UN_KLOCK)
+			panic("union: dangling upper lock");
+#endif
+	}
+
+	if (un->un_flags & UN_LOCKED) {
+#ifdef DIAGNOSTIC
+		if (curproc && un->un_pid == curproc->p_pid &&
+			    un->un_pid > -1 && curproc->p_pid > -1)
+			panic("union: locking against myself");
+#endif
+		un->un_flags |= UN_WANT;
+		sleep((caddr_t) &un->un_flags, PINOD);
+		goto start;
+	}
+
+#ifdef DIAGNOSTIC
+	if (curproc)
+		un->un_pid = curproc->p_pid;
+	else
+		un->un_pid = -1;
+#endif
+
+	un->un_flags |= UN_LOCKED;
+	return (0);
+}
+
+int
+union_unlock(ap)
+	struct vop_lock_args *ap;
+{
+	struct union_node *un = VTOUNION(ap->a_vp);
+
+#ifdef DIAGNOSTIC
+	if ((un->un_flags & UN_LOCKED) == 0)
+		panic("union: unlock unlocked node");
+	if (curproc && un->un_pid != curproc->p_pid &&
+			curproc->p_pid > -1 && un->un_pid > -1)
+		panic("union: unlocking other process's union node");
+#endif
+
+	un->un_flags &= ~UN_LOCKED;
+
+	if ((un->un_flags & (UN_ULOCK|UN_KLOCK)) == UN_ULOCK)
+		VOP_UNLOCK(un->un_uppervp);
+
+	un->un_flags &= ~(UN_ULOCK|UN_KLOCK);
+
+	if (un->un_flags & UN_WANT) {
+		un->un_flags &= ~UN_WANT;
+		wakeup((caddr_t) &un->un_flags);
+	}
+
+#ifdef DIAGNOSTIC
+	un->un_pid = 0;
+#endif
+
+	return (0);
+}
+
+int
+union_bmap(ap)
+	struct vop_bmap_args /* {
+		struct vnode *a_vp;
+		daddr_t  a_bn;
+		struct vnode **a_vpp;
+		daddr_t *a_bnp;
+		int *a_runp;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_vp);
+	int dolock = (vp == LOWERVP(ap->a_vp));
+
+	if (dolock)
+		VOP_LOCK(vp);
+	else
+		FIXUP(VTOUNION(ap->a_vp));
+	error = VOP_BMAP(vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp);
+	if (dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_print(ap)
+	struct vop_print_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+	struct vnode *vp = ap->a_vp;
+
+	printf("\ttag VT_UNION, vp=%x, uppervp=%x, lowervp=%x\n",
+			vp, UPPERVP(vp), LOWERVP(vp));
+	return (0);
+}
+
+int
+union_islocked(ap)
+	struct vop_islocked_args /* {
+		struct vnode *a_vp;
+	} */ *ap;
+{
+
+	return ((VTOUNION(ap->a_vp)->un_flags & UN_LOCKED) ? 1 : 0);
+}
+
+int
+union_pathconf(ap)
+	struct vop_pathconf_args /* {
+		struct vnode *a_vp;
+		int a_name;
+		int *a_retval;
+	} */ *ap;
+{
+	int error;
+	struct vnode *vp = OTHERVP(ap->a_vp);
+	int dolock = (vp == LOWERVP(ap->a_vp));
+
+	if (dolock)
+		VOP_LOCK(vp);
+	else
+		FIXUP(VTOUNION(ap->a_vp));
+	error = VOP_PATHCONF(vp, ap->a_name, ap->a_retval);
+	if (dolock)
+		VOP_UNLOCK(vp);
+
+	return (error);
+}
+
+int
+union_advlock(ap)
+	struct vop_advlock_args /* {
+		struct vnode *a_vp;
+		caddr_t  a_id;
+		int  a_op;
+		struct flock *a_fl;
+		int  a_flags;
+	} */ *ap;
+{
+
+	return (VOP_ADVLOCK(OTHERVP(ap->a_vp), ap->a_id, ap->a_op,
+				ap->a_fl, ap->a_flags));
+}
+
+
+/*
+ * XXX - vop_strategy must be hand coded because it has no
+ * vnode in its arguments.
+ * This goes away with a merged VM/buffer cache.
+ */
+int
+union_strategy(ap)
+	struct vop_strategy_args /* {
+		struct buf *a_bp;
+	} */ *ap;
+{
+	struct buf *bp = ap->a_bp;
+	int error;
+	struct vnode *savedvp;
+
+	savedvp = bp->b_vp;
+	bp->b_vp = OTHERVP(bp->b_vp);
+
+#ifdef DIAGNOSTIC
+	if (bp->b_vp == NULLVP)
+		panic("union_strategy: nil vp");
+	if (((bp->b_flags & B_READ) == 0) &&
+	    (bp->b_vp == LOWERVP(savedvp)))
+		panic("union_strategy: writing to lowervp");
+#endif
+
+	error = VOP_STRATEGY(bp);
+	bp->b_vp = savedvp;
+
+	return (error);
+}
+
+/*
+ * Global vfs data structures
+ */
+int (**union_vnodeop_p)();
+struct vnodeopv_entry_desc union_vnodeop_entries[] = {
+	{ &vop_default_desc, vn_default_error },
+	{ &vop_lookup_desc, union_lookup },		/* lookup */
+	{ &vop_create_desc, union_create },		/* create */
+	{ &vop_mknod_desc, union_mknod },		/* mknod */
+	{ &vop_open_desc, union_open },			/* open */
+	{ &vop_close_desc, union_close },		/* close */
+	{ &vop_access_desc, union_access },		/* access */
+	{ &vop_getattr_desc, union_getattr },		/* getattr */
+	{ &vop_setattr_desc, union_setattr },		/* setattr */
+	{ &vop_read_desc, union_read },			/* read */
+	{ &vop_write_desc, union_write },		/* write */
+	{ &vop_ioctl_desc, union_ioctl },		/* ioctl */
+	{ &vop_select_desc, union_select },		/* select */
+	{ &vop_mmap_desc, union_mmap },			/* mmap */
+	{ &vop_fsync_desc, union_fsync },		/* fsync */
+	{ &vop_seek_desc, union_seek },			/* seek */
+	{ &vop_remove_desc, union_remove },		/* remove */
+	{ &vop_link_desc, union_link },			/* link */
+	{ &vop_rename_desc, union_rename },		/* rename */
+	{ &vop_mkdir_desc, union_mkdir },		/* mkdir */
+	{ &vop_rmdir_desc, union_rmdir },		/* rmdir */
+	{ &vop_symlink_desc, union_symlink },		/* symlink */
+	{ &vop_readdir_desc, union_readdir },		/* readdir */
+	{ &vop_readlink_desc, union_readlink },		/* readlink */
+	{ &vop_abortop_desc, union_abortop },		/* abortop */
+	{ &vop_inactive_desc, union_inactive },		/* inactive */
+	{ &vop_reclaim_desc, union_reclaim },		/* reclaim */
+	{ &vop_lock_desc, union_lock },			/* lock */
+	{ &vop_unlock_desc, union_unlock },		/* unlock */
+	{ &vop_bmap_desc, union_bmap },			/* bmap */
+	{ &vop_strategy_desc, union_strategy },		/* strategy */
+	{ &vop_print_desc, union_print },		/* print */
+	{ &vop_islocked_desc, union_islocked },		/* islocked */
+	{ &vop_pathconf_desc, union_pathconf },		/* pathconf */
+	{ &vop_advlock_desc, union_advlock },		/* advlock */
+#ifdef notdef
+	{ &vop_blkatoff_desc, union_blkatoff },		/* blkatoff */
+	{ &vop_valloc_desc, union_valloc },		/* valloc */
+	{ &vop_vfree_desc, union_vfree },		/* vfree */
+	{ &vop_truncate_desc, union_truncate },		/* truncate */
+	{ &vop_update_desc, union_update },		/* update */
+	{ &vop_bwrite_desc, union_bwrite },		/* bwrite */
+#endif
+	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
+};
+struct vnodeopv_desc union_vnodeop_opv_desc =
+	{ &union_vnodeop_p, union_vnodeop_entries };