/*-
 *  modified for EXT2FS support in Lites 1.1
 *
 *  Aug 1995, Godmar Back (gback@cs.utah.edu)
 *  University of Utah, Department of Computer Science
 */
/*-
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 * (c) UNIX System Laboratories, Inc.
 * All or some portions of this file are derived from material licensed
 * to the University of California by American Telephone and Telegraph
 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
 * the permission of UNIX System Laboratories, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ufs_vnops.c	8.7 (Berkeley) 2/3/94
 *	@(#)ufs_vnops.c 8.27 (Berkeley) 5/27/95
 * $FreeBSD: src/sys/gnu/fs/ext2fs/ext2_vnops.c,v 1.105 2005/12/29 21:34:49 cracauer Exp $
 */

#include "opt_suiddir.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/resourcevar.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/unistd.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/namei.h>
#include <sys/lockf.h>
#include <sys/event.h>
#include <sys/conf.h>
#include <sys/file.h>

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

#include <fs/fifofs/fifo.h>

#include <sys/signalvar.h>
#include <ufs/ufs/dir.h>

#include <gnu/fs/ext2fs/inode.h>
#include <gnu/fs/ext2fs/ext2_mount.h>
#include <gnu/fs/ext2fs/ext2_fs_sb.h>
#include <gnu/fs/ext2fs/fs.h>
#include <gnu/fs/ext2fs/ext2_extern.h>
#include <gnu/fs/ext2fs/ext2_fs.h>

static int ext2_makeinode(int mode, struct vnode *, struct vnode **, struct componentname *);

static vop_access_t	ext2_access;
static vop_advlock_t	ext2_advlock;
static int ext2_chmod(struct vnode *, int, struct ucred *, struct thread *);
static int ext2_chown(struct vnode *, uid_t, gid_t, struct ucred *,
    struct thread *);
static vop_close_t	ext2_close;
static vop_create_t	ext2_create;
static vop_fsync_t	ext2_fsync;
static vop_getattr_t	ext2_getattr;
static vop_kqfilter_t	ext2_kqfilter;
static vop_link_t	ext2_link;
static vop_mkdir_t	ext2_mkdir;
static vop_mknod_t	ext2_mknod;
static vop_open_t	ext2_open;
static vop_pathconf_t	ext2_pathconf;
static vop_print_t	ext2_print;
static vop_read_t	ext2_read;
static vop_readlink_t	ext2_readlink;
static vop_remove_t	ext2_remove;
static vop_rename_t	ext2_rename;
static vop_rmdir_t	ext2_rmdir;
static vop_setattr_t	ext2_setattr;
static vop_strategy_t	ext2_strategy;
static vop_symlink_t	ext2_symlink;
static vop_write_t	ext2_write;
static vop_close_t	ext2fifo_close;
static vop_kqfilter_t	ext2fifo_kqfilter;
static int filt_ext2read(struct knote *kn, long hint);
static int filt_ext2write(struct knote *kn, long hint);
static int filt_ext2vnode(struct knote *kn, long hint);
static void filt_ext2detach(struct knote *kn);

/* Global vfs data structures for ext2. */
struct vop_vector ext2_vnodeops = {
	.vop_default =		&default_vnodeops,
	.vop_access =		ext2_access,
	.vop_advlock =		ext2_advlock,
	.vop_bmap =		ext2_bmap,
	.vop_cachedlookup =	ext2_lookup,
	.vop_close =		ext2_close,
	.vop_create =		ext2_create,
	.vop_fsync =		ext2_fsync,
	.vop_getattr =		ext2_getattr,
	.vop_inactive =		ext2_inactive,
	.vop_link =		ext2_link,
	.vop_lookup =		vfs_cache_lookup,
	.vop_mkdir =		ext2_mkdir,
	.vop_mknod =		ext2_mknod,
	.vop_open =		ext2_open,
	.vop_pathconf =		ext2_pathconf,
	.vop_poll =		vop_stdpoll,
	.vop_kqfilter =		ext2_kqfilter,
	.vop_print =		ext2_print,
	.vop_read =		ext2_read,
	.vop_readdir =		ext2_readdir,
	.vop_readlink =		ext2_readlink,
	.vop_reallocblks =	ext2_reallocblks,
	.vop_reclaim =		ext2_reclaim,
	.vop_remove =		ext2_remove,
	.vop_rename =		ext2_rename,
	.vop_rmdir =		ext2_rmdir,
	.vop_setattr =		ext2_setattr,
	.vop_strategy =		ext2_strategy,
	.vop_symlink =		ext2_symlink,
	.vop_write =		ext2_write,
};

struct vop_vector ext2_fifoops = {
	.vop_default =		&fifo_specops,
	.vop_access =		ext2_access,
	.vop_close =		ext2fifo_close,
	.vop_fsync =		ext2_fsync,
	.vop_getattr =		ext2_getattr,
	.vop_inactive =		ext2_inactive,
	.vop_kqfilter =		ext2fifo_kqfilter,
	.vop_print =		ext2_print,
	.vop_read =		VOP_PANIC,
	.vop_reclaim =		ext2_reclaim,
	.vop_setattr =		ext2_setattr,
	.vop_write =		VOP_PANIC,
};

#include <gnu/fs/ext2fs/ext2_readwrite.c>

/*
 * A virgin directory (no blushing please).
 * Note that the type and namlen fields are reversed relative to ext2.
 * Also, we don't use `struct odirtemplate', since it would just cause
 * endianness problems.
 */
static struct dirtemplate mastertemplate = {
	0, 12, 1, EXT2_FT_DIR, ".",
	0, DIRBLKSIZ - 12, 2, EXT2_FT_DIR, ".."
};
static struct dirtemplate omastertemplate = {
	0, 12, 1, EXT2_FT_UNKNOWN, ".",
	0, DIRBLKSIZ - 12, 2, EXT2_FT_UNKNOWN, ".."
};

void
ext2_itimes(vp)
	struct vnode *vp;
{
	struct inode *ip;
	struct timespec ts;

	ip = VTOI(vp);
	if ((ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_UPDATE)) == 0)
		return;
	if ((vp->v_type == VBLK || vp->v_type == VCHR))
		ip->i_flag |= IN_LAZYMOD;
	else
		ip->i_flag |= IN_MODIFIED;
	if ((vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
		vfs_timestamp(&ts);
		if (ip->i_flag & IN_ACCESS) {
			ip->i_atime = ts.tv_sec;
			ip->i_atimensec = ts.tv_nsec;
		}
		if (ip->i_flag & IN_UPDATE) {
			ip->i_mtime = ts.tv_sec;
			ip->i_mtimensec = ts.tv_nsec;
			ip->i_modrev++;
		}
		if (ip->i_flag & IN_CHANGE) {
			ip->i_ctime = ts.tv_sec;
			ip->i_ctimensec = ts.tv_nsec;
		}
	}
	ip->i_flag &= ~(IN_ACCESS | IN_CHANGE | IN_UPDATE);
}

/*
 * Create a regular file
 */
static int
ext2_create(ap)
	struct vop_create_args /* {
		struct vnode *a_dvp;
		struct vnode **a_vpp;
		struct componentname *a_cnp;
		struct vattr *a_vap;
	} */ *ap;
{
	int error;

	error =
	    ext2_makeinode(MAKEIMODE(ap->a_vap->va_type, ap->a_vap->va_mode),
	    ap->a_dvp, ap->a_vpp, ap->a_cnp);
	if (error)
		return (error);
	return (0);
}

static int
ext2_open(ap)
	struct vop_open_args /* {
		struct vnode *a_vp;
		int  a_mode;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{

	if (ap->a_vp->v_type == VBLK || ap->a_vp->v_type == VCHR)
		return (EOPNOTSUPP);

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

	vnode_create_vobject(ap->a_vp, VTOI(ap->a_vp)->i_size, ap->a_td);

	return (0);
}

/*
 * Close called.
 *
 * Update the times on the inode.
 */
static int
ext2_close(ap)
	struct vop_close_args /* {
		struct vnode *a_vp;
		int  a_fflag;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;

	VI_LOCK(vp);
	if (vp->v_usecount > 1)
		ext2_itimes(vp);
	VI_UNLOCK(vp);
	return (0);
}

static int
ext2_access(ap)
	struct vop_access_args /* {
		struct vnode *a_vp;
		int  a_mode;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct inode *ip = VTOI(vp);
	mode_t mode = ap->a_mode;
	int error;

	if (vp->v_type == VBLK || vp->v_type == VCHR)
		return (EOPNOTSUPP);

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

	/* If immutable bit set, nobody gets to write it. */
	if ((mode & VWRITE) && (ip->i_flags & (IMMUTABLE | SF_SNAPSHOT)))
		return (EPERM);

	error = vaccess(vp->v_type, ip->i_mode, ip->i_uid, ip->i_gid,
	    ap->a_mode, ap->a_cred, NULL);
	return (error);
}

static int
ext2_getattr(ap)
	struct vop_getattr_args /* {
		struct vnode *a_vp;
		struct vattr *a_vap;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct inode *ip = VTOI(vp);
	struct vattr *vap = ap->a_vap;

	ext2_itimes(vp);
	/*
	 * Copy from inode table
	 */
	vap->va_fsid = dev2udev(ip->i_devvp->v_rdev);
	vap->va_fileid = ip->i_number;
	vap->va_mode = ip->i_mode & ~IFMT;
	vap->va_nlink = ip->i_nlink;
	vap->va_uid = ip->i_uid;
	vap->va_gid = ip->i_gid;
	vap->va_rdev = ip->i_rdev;
	vap->va_size = ip->i_size;
	vap->va_atime.tv_sec = ip->i_atime;
	vap->va_atime.tv_nsec = ip->i_atimensec;
	vap->va_mtime.tv_sec = ip->i_mtime;
	vap->va_mtime.tv_nsec = ip->i_mtimensec;
	vap->va_ctime.tv_sec = ip->i_ctime;
	vap->va_ctime.tv_nsec = ip->i_ctimensec;
	vap->va_flags = ip->i_flags;
	vap->va_gen = ip->i_gen;
	vap->va_blocksize = vp->v_mount->mnt_stat.f_iosize;
	vap->va_bytes = dbtob((u_quad_t)ip->i_blocks);
	vap->va_type = IFTOVT(ip->i_mode);
	vap->va_filerev = ip->i_modrev;
	return (0);
}

/*
 * Set attribute vnode op. called from several syscalls
 */
static int
ext2_setattr(ap)
	struct vop_setattr_args /* {
		struct vnode *a_vp;
		struct vattr *a_vap;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{
	struct vattr *vap = ap->a_vap;
	struct vnode *vp = ap->a_vp;
	struct inode *ip = VTOI(vp);
	struct ucred *cred = ap->a_cred;
	struct thread *td = ap->a_td;
	int error;

	/*
	 * Check for unsettable attributes.
	 */
	if ((vap->va_type != VNON) || (vap->va_nlink != VNOVAL) ||
	    (vap->va_fsid != VNOVAL) || (vap->va_fileid != VNOVAL) ||
	    (vap->va_blocksize != VNOVAL) || (vap->va_rdev != VNOVAL) ||
	    ((int)vap->va_bytes != VNOVAL) || (vap->va_gen != VNOVAL)) {
		return (EINVAL);
	}
	if (vap->va_flags != VNOVAL) {
		if (vp->v_mount->mnt_flag & MNT_RDONLY)
			return (EROFS);
		/*
		 * Callers may only modify the file flags on objects they
		 * have VADMIN rights for.
		 */
		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
			return (error);
		/*
		 * Unprivileged processes and privileged processes in
		 * jail() are not permitted to unset system flags, or
		 * modify flags if any system flags are set.
		 * Privileged non-jail processes may not modify system flags
		 * if securelevel > 0 and any existing system flags are set.
		 */
		if (!suser_cred(cred, SUSER_ALLOWJAIL)) {
			if (ip->i_flags
			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
				error = securelevel_gt(cred, 0);
				if (error)
					return (error);
			}
			ip->i_flags = vap->va_flags;
		} else {
			if (ip->i_flags
			    & (SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
			    (vap->va_flags & UF_SETTABLE) != vap->va_flags)
				return (EPERM);
			ip->i_flags &= SF_SETTABLE;
			ip->i_flags |= (vap->va_flags & UF_SETTABLE);
		}
		ip->i_flag |= IN_CHANGE;
		if (vap->va_flags & (IMMUTABLE | APPEND))
			return (0);
	}
	if (ip->i_flags & (IMMUTABLE | APPEND))
		return (EPERM);
	/*
	 * Go through the fields and update iff not VNOVAL.
	 */
	if (vap->va_uid != (uid_t)VNOVAL || vap->va_gid != (gid_t)VNOVAL) {
		if (vp->v_mount->mnt_flag & MNT_RDONLY)
			return (EROFS);
		if ((error = ext2_chown(vp, vap->va_uid, vap->va_gid, cred,
		    td)) != 0)
			return (error);
	}
	if (vap->va_size != VNOVAL) {
		/*
		 * Disallow write attempts on read-only file systems;
		 * unless the file is a socket, fifo, or a block or
		 * character device resident on the file system.
		 */
		switch (vp->v_type) {
		case VDIR:
			return (EISDIR);
		case VLNK:
		case VREG:
			if (vp->v_mount->mnt_flag & MNT_RDONLY)
				return (EROFS);
			break;
		default:
			break;
		}
		if ((error = ext2_truncate(vp, vap->va_size, 0, cred, td)) != 0)
			return (error);
	}
	if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
		if (vp->v_mount->mnt_flag & MNT_RDONLY)
			return (EROFS);
		/*
		 * From utimes(2):
		 * If times is NULL, ... The caller must be the owner of
		 * the file, have permission to write the file, or be the
		 * super-user.
		 * If times is non-NULL, ... The caller must be the owner of
		 * the file or be the super-user.
		 */
		if ((error = VOP_ACCESS(vp, VADMIN, cred, td)) &&
		    ((vap->va_vaflags & VA_UTIMES_NULL) == 0 ||
		    (error = VOP_ACCESS(vp, VWRITE, cred, td))))
			return (error);
		if (vap->va_atime.tv_sec != VNOVAL)
			ip->i_flag |= IN_ACCESS;
		if (vap->va_mtime.tv_sec != VNOVAL)
			ip->i_flag |= IN_CHANGE | IN_UPDATE;
		ext2_itimes(vp);
		if (vap->va_atime.tv_sec != VNOVAL) {
			ip->i_atime = vap->va_atime.tv_sec;
			ip->i_atimensec = vap->va_atime.tv_nsec;
		}
		if (vap->va_mtime.tv_sec != VNOVAL) {
			ip->i_mtime = vap->va_mtime.tv_sec;
			ip->i_mtimensec = vap->va_mtime.tv_nsec;
		}
		error = ext2_update(vp, 0);
		if (error)
			return (error);
	}
	error = 0;
	if (vap->va_mode != (mode_t)VNOVAL) {
		if (vp->v_mount->mnt_flag & MNT_RDONLY)
			return (EROFS);
		error = ext2_chmod(vp, (int)vap->va_mode, cred, td);
	}
	return (error);
}

/*
 * Change the mode on a file.
 * Inode must be locked before calling.
 */
static int
ext2_chmod(vp, mode, cred, td)
	struct vnode *vp;
	int mode;
	struct ucred *cred;
	struct thread *td;
{
	struct inode *ip = VTOI(vp);
	int error;

	/*
	 * To modify the permissions on a file, must possess VADMIN
	 * for that file.
	 */
	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
		return (error);
	/*
	 * Privileged processes may set the sticky bit on non-directories,
	 * as well as set the setgid bit on a file with a group that the
	 * process is not a member of.
	 */
	if (suser_cred(cred, SUSER_ALLOWJAIL)) {
		if (vp->v_type != VDIR && (mode & S_ISTXT))
			return (EFTYPE);
		if (!groupmember(ip->i_gid, cred) && (mode & ISGID))
			return (EPERM);
	}
	ip->i_mode &= ~ALLPERMS;
	ip->i_mode |= (mode & ALLPERMS);
	ip->i_flag |= IN_CHANGE;
	return (0);
}

/*
 * Perform chown operation on inode ip;
 * inode must be locked prior to call.
 */
static int
ext2_chown(vp, uid, gid, cred, td)
	struct vnode *vp;
	uid_t uid;
	gid_t gid;
	struct ucred *cred;
	struct thread *td;
{
	struct inode *ip = VTOI(vp);
	uid_t ouid;
	gid_t ogid;
	int error = 0;

	if (uid == (uid_t)VNOVAL)
		uid = ip->i_uid;
	if (gid == (gid_t)VNOVAL)
		gid = ip->i_gid;
	/*
	 * To modify the ownership of a file, must possess VADMIN
	 * for that file.
	 */
	if ((error = VOP_ACCESS(vp, VADMIN, cred, td)))
		return (error);
	/*
	 * To change the owner of a file, or change the group of a file
	 * to a group of which we are not a member, the caller must
	 * have privilege.
	 */
	if ((uid != ip->i_uid || 
	    (gid != ip->i_gid && !groupmember(gid, cred))) &&
	    (error = suser_cred(cred, SUSER_ALLOWJAIL)))
		return (error);
	ogid = ip->i_gid;
	ouid = ip->i_uid;
	ip->i_gid = gid;
	ip->i_uid = uid;
	ip->i_flag |= IN_CHANGE;
	if (suser_cred(cred, SUSER_ALLOWJAIL) && (ouid != uid || ogid != gid))
		ip->i_mode &= ~(ISUID | ISGID);
	return (0);
}

/*
 * Synch an open file.
 */
/* ARGSUSED */
static int
ext2_fsync(ap)
	struct vop_fsync_args /* {
		struct vnode *a_vp;
		struct ucred *a_cred;
		int a_waitfor;
		struct thread *a_td;
	} */ *ap;
{
	/*
	 * Flush all dirty buffers associated with a vnode.
	 */
	ext2_discard_prealloc(VTOI(ap->a_vp));

	vop_stdfsync(ap);

	return (ext2_update(ap->a_vp, ap->a_waitfor == MNT_WAIT));
}

/*
 * Mknod vnode call
 */
/* ARGSUSED */
static int
ext2_mknod(ap)
	struct vop_mknod_args /* {
		struct vnode *a_dvp;
		struct vnode **a_vpp;
		struct componentname *a_cnp;
		struct vattr *a_vap;
	} */ *ap;
{
	struct vattr *vap = ap->a_vap;
	struct vnode **vpp = ap->a_vpp;
	struct inode *ip;
	ino_t ino;
	int error;

	error = ext2_makeinode(MAKEIMODE(vap->va_type, vap->va_mode),
	    ap->a_dvp, vpp, ap->a_cnp);
	if (error)
		return (error);
	ip = VTOI(*vpp);
	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
	if (vap->va_rdev != VNOVAL) {
		/*
		 * Want to be able to use this to make badblock
		 * inodes, so don't truncate the dev number.
		 */
		ip->i_rdev = vap->va_rdev;
	}
	/*
	 * Remove inode, then reload it through VFS_VGET so it is
	 * checked to see if it is an alias of an existing entry in
	 * the inode cache.	 XXX I don't believe this is necessary now.
	 */
	(*vpp)->v_type = VNON;
	ino = ip->i_number;	/* Save this before vgone() invalidates ip. */
	vgone(*vpp);
	vput(*vpp);
	error = VFS_VGET(ap->a_dvp->v_mount, ino, LK_EXCLUSIVE, vpp);
	if (error) {
		*vpp = NULL;
		return (error);
	}
	return (0);
}

static int
ext2_remove(ap)
	struct vop_remove_args /* {
		struct vnode *a_dvp;
		struct vnode *a_vp;
		struct componentname *a_cnp;
	} */ *ap;
{
	struct inode *ip;
	struct vnode *vp = ap->a_vp;
	struct vnode *dvp = ap->a_dvp;
	int error;

	ip = VTOI(vp);
	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
	    (VTOI(dvp)->i_flags & APPEND)) {
		error = EPERM;
		goto out;
	}
	error = ext2_dirremove(dvp, ap->a_cnp);
	if (error == 0) {
		ip->i_nlink--;
		ip->i_flag |= IN_CHANGE;
	}
out:
	return (error);
}

/*
 * link vnode call
 */
static int
ext2_link(ap)
	struct vop_link_args /* {
		struct vnode *a_tdvp;
		struct vnode *a_vp;
		struct componentname *a_cnp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct vnode *tdvp = ap->a_tdvp;
	struct componentname *cnp = ap->a_cnp;
	struct inode *ip;
	int error;

#ifdef DIAGNOSTIC
	if ((cnp->cn_flags & HASBUF) == 0)
		panic("ext2_link: no name");
#endif
	if (tdvp->v_mount != vp->v_mount) {
		error = EXDEV;
		goto out;
	}
	ip = VTOI(vp);
	if ((nlink_t)ip->i_nlink >= LINK_MAX) {
		error = EMLINK;
		goto out;
	}
	if (ip->i_flags & (IMMUTABLE | APPEND)) {
		error = EPERM;
		goto out;
	}
	ip->i_nlink++;
	ip->i_flag |= IN_CHANGE;
	error = ext2_update(vp, 1);
	if (!error)
		error = ext2_direnter(ip, tdvp, cnp);
	if (error) {
		ip->i_nlink--;
		ip->i_flag |= IN_CHANGE;
	}
out:
	return (error);
}

/*
 * Rename system call.
 *   See comments in sys/ufs/ufs/ufs_vnops.c
 */
static int
ext2_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;
{
	struct vnode *tvp = ap->a_tvp;
	struct vnode *tdvp = ap->a_tdvp;
	struct vnode *fvp = ap->a_fvp;
	struct vnode *fdvp = ap->a_fdvp;
	struct componentname *tcnp = ap->a_tcnp;
	struct componentname *fcnp = ap->a_fcnp;
	struct thread *td = fcnp->cn_thread;
	struct inode *ip, *xp, *dp;
	struct dirtemplate dirbuf;
	int doingdirectory = 0, oldparent = 0, newparent = 0;
	int error = 0;
	u_char namlen;

#ifdef DIAGNOSTIC
	if ((tcnp->cn_flags & HASBUF) == 0 ||
	    (fcnp->cn_flags & HASBUF) == 0)
		panic("ext2_rename: no name");
#endif
	/*
	 * Check for cross-device rename.
	 */
	if ((fvp->v_mount != tdvp->v_mount) ||
	    (tvp && (fvp->v_mount != tvp->v_mount))) {
		error = EXDEV;
abortit:
		if (tdvp == tvp)
			vrele(tdvp);
		else
			vput(tdvp);
		if (tvp)
			vput(tvp);
		vrele(fdvp);
		vrele(fvp);
		return (error);
	}

	if (tvp && ((VTOI(tvp)->i_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
	    (VTOI(tdvp)->i_flags & APPEND))) {
		error = EPERM;
		goto abortit;
	}

	/*
	 * Renaming a file to itself has no effect.  The upper layers should
	 * not call us in that case.  Temporarily just warn if they do.
	 */
	if (fvp == tvp) {
		printf("ext2_rename: fvp == tvp (can't happen)\n");
		error = 0;
		goto abortit;
	}

	if ((error = vn_lock(fvp, LK_EXCLUSIVE, td)) != 0)
		goto abortit;
	dp = VTOI(fdvp);
	ip = VTOI(fvp);
 	if (ip->i_nlink >= LINK_MAX) {
 		VOP_UNLOCK(fvp, 0, td);
 		error = EMLINK;
 		goto abortit;
 	}
	if ((ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))
	    || (dp->i_flags & APPEND)) {
		VOP_UNLOCK(fvp, 0, td);
		error = EPERM;
		goto abortit;
	}
	if ((ip->i_mode & IFMT) == IFDIR) {
		/*
		 * Avoid ".", "..", and aliases of "." for obvious reasons.
		 */
		if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.') ||
		    dp == ip || (fcnp->cn_flags | tcnp->cn_flags) & ISDOTDOT ||
		    (ip->i_flag & IN_RENAME)) {
			VOP_UNLOCK(fvp, 0, td);
			error = EINVAL;
			goto abortit;
		}
		ip->i_flag |= IN_RENAME;
		oldparent = dp->i_number;
		doingdirectory++;
	}
	vrele(fdvp);

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

	/*
	 * 1) Bump link count while we're moving stuff
	 *    around.  If we crash somewhere before
	 *    completing our work, the link count
	 *    may be wrong, but correctable.
	 */
	ip->i_nlink++;
	ip->i_flag |= IN_CHANGE;
	if ((error = ext2_update(fvp, 1)) != 0) {
		VOP_UNLOCK(fvp, 0, td);
		goto bad;
	}

	/*
	 * If ".." must be changed (ie the directory gets a new
	 * parent) then the source directory must not be in the
	 * directory heirarchy above the target, as this would
	 * orphan everything below the source directory. Also
	 * the user must have write permission in the source so
	 * as to be able to change "..". We must repeat the call
	 * to namei, as the parent directory is unlocked by the
	 * call to checkpath().
	 */
	error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_thread);
	VOP_UNLOCK(fvp, 0, td);
	if (oldparent != dp->i_number)
		newparent = dp->i_number;
	if (doingdirectory && newparent) {
		if (error)	/* write access check above */
			goto bad;
		if (xp != NULL)
			vput(tvp);
		error = ext2_checkpath(ip, dp, tcnp->cn_cred);
		if (error)
			goto out;
		VREF(tdvp);
		error = relookup(tdvp, &tvp, tcnp);
		if (error)
			goto out;
		vrele(tdvp);
		dp = VTOI(tdvp);
		xp = NULL;
		if (tvp)
			xp = VTOI(tvp);
	}
	/*
	 * 2) If target doesn't exist, link the target
	 *    to the source and unlink the source.
	 *    Otherwise, rewrite the target directory
	 *    entry to reference the source inode and
	 *    expunge the original entry's existence.
	 */
	if (xp == NULL) {
		if (dp->i_devvp != ip->i_devvp)
			panic("ext2_rename: EXDEV");
		/*
		 * Account for ".." in new directory.
		 * When source and destination have the same
		 * parent we don't fool with the link count.
		 */
		if (doingdirectory && newparent) {
			if ((nlink_t)dp->i_nlink >= LINK_MAX) {
				error = EMLINK;
				goto bad;
			}
			dp->i_nlink++;
			dp->i_flag |= IN_CHANGE;
			error = ext2_update(tdvp, 1);
			if (error)
				goto bad;
		}
		error = ext2_direnter(ip, tdvp, tcnp);
		if (error) {
			if (doingdirectory && newparent) {
				dp->i_nlink--;
				dp->i_flag |= IN_CHANGE;
				(void)ext2_update(tdvp, 1);
			}
			goto bad;
		}
		vput(tdvp);
	} else {
		if (xp->i_devvp != dp->i_devvp || xp->i_devvp != ip->i_devvp)
		       panic("ext2_rename: EXDEV");
		/*
		 * Short circuit rename(foo, foo).
		 */
		if (xp->i_number == ip->i_number)
			panic("ext2_rename: same file");
		/*
		 * If the parent directory is "sticky", then the user must
		 * own the parent directory, or the destination of the rename,
		 * otherwise the destination may not be changed (except by
		 * root). This implements append-only directories.
		 */
		if ((dp->i_mode & S_ISTXT) && tcnp->cn_cred->cr_uid != 0 &&
		    tcnp->cn_cred->cr_uid != dp->i_uid &&
		    xp->i_uid != tcnp->cn_cred->cr_uid) {
			error = EPERM;
			goto bad;
		}
		/*
		 * Target must be empty if a directory and have no links
		 * to it. Also, ensure source and target are compatible
		 * (both directories, or both not directories).
		 */
		if ((xp->i_mode&IFMT) == IFDIR) {
			if (! ext2_dirempty(xp, dp->i_number, tcnp->cn_cred) || 
			    xp->i_nlink > 2) {
				error = ENOTEMPTY;
				goto bad;
			}
			if (!doingdirectory) {
				error = ENOTDIR;
				goto bad;
			}
			cache_purge(tdvp);
		} else if (doingdirectory) {
			error = EISDIR;
			goto bad;
		}
		error = ext2_dirrewrite(dp, ip, tcnp);
		if (error)
			goto bad;
		/*
		 * If the target directory is in the same
		 * directory as the source directory,
		 * decrement the link count on the parent
		 * of the target directory.
		 */
		if (doingdirectory && !newparent) {
		       dp->i_nlink--;
		       dp->i_flag |= IN_CHANGE;
		}
		vput(tdvp);
		/*
		 * Adjust the link count of the target to
		 * reflect the dirrewrite above.  If this is
		 * a directory it is empty and there are
		 * no links to it, so we can squash the inode and
		 * any space associated with it.  We disallowed
		 * renaming over top of a directory with links to
		 * it above, as the remaining link would point to
		 * a directory without "." or ".." entries.
		 */
		xp->i_nlink--;
		if (doingdirectory) {
			if (--xp->i_nlink != 0)
				panic("ext2_rename: linked directory");
			error = ext2_truncate(tvp, (off_t)0, IO_SYNC,
			    tcnp->cn_cred, tcnp->cn_thread);
		}
		xp->i_flag |= IN_CHANGE;
		vput(tvp);
		xp = NULL;
	}

	/*
	 * 3) Unlink the source.
	 */
	fcnp->cn_flags &= ~MODMASK;
	fcnp->cn_flags |= LOCKPARENT | LOCKLEAF;
	VREF(fdvp);
	error = relookup(fdvp, &fvp, fcnp);
	if (error == 0)
		vrele(fdvp);
	if (fvp != NULL) {
		xp = VTOI(fvp);
		dp = VTOI(fdvp);
	} else {
		/*
		 * From name has disappeared.
		 */
		if (doingdirectory)
			panic("ext2_rename: lost dir entry");
		vrele(ap->a_fvp);
		return (0);
	}
	/*
	 * Ensure that the directory entry still exists and has not
	 * changed while the new name has been entered. If the source is
	 * a file then the entry may have been unlinked or renamed. In
	 * either case there is no further work to be done. If the source
	 * is a directory then it cannot have been rmdir'ed; its link
	 * count of three would cause a rmdir to fail with ENOTEMPTY.
	 * The IN_RENAME flag ensures that it cannot be moved by another
	 * rename.
	 */
	if (xp != ip) {
		if (doingdirectory)
			panic("ext2_rename: lost dir entry");
	} else {
		/*
		 * If the source is a directory with a
		 * new parent, the link count of the old
		 * parent directory must be decremented
		 * and ".." set to point to the new parent.
		 */
		if (doingdirectory && newparent) {
			dp->i_nlink--;
			dp->i_flag |= IN_CHANGE;
			error = vn_rdwr(UIO_READ, fvp, (caddr_t)&dirbuf,
				sizeof (struct dirtemplate), (off_t)0,
				UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
				tcnp->cn_cred, NOCRED, (int *)0,
				(struct thread *)0);
			if (error == 0) {
				/* Like ufs little-endian: */
				namlen = dirbuf.dotdot_type;
				if (namlen != 2 ||
				    dirbuf.dotdot_name[0] != '.' ||
				    dirbuf.dotdot_name[1] != '.') {
					ext2_dirbad(xp, (doff_t)12,
					    "rename: mangled dir");
				} else {
					dirbuf.dotdot_ino = newparent;
					(void) vn_rdwr(UIO_WRITE, fvp,
					    (caddr_t)&dirbuf,
					    sizeof (struct dirtemplate),
					    (off_t)0, UIO_SYSSPACE,
					    IO_NODELOCKED | IO_SYNC |
					    IO_NOMACCHECK, tcnp->cn_cred,
					    NOCRED, (int *)0,
					    (struct thread *)0);
					cache_purge(fdvp);
				}
			}
		}
		error = ext2_dirremove(fdvp, fcnp);
		if (!error) {
			xp->i_nlink--;
			xp->i_flag |= IN_CHANGE;
		}
		xp->i_flag &= ~IN_RENAME;
	}
	if (dp)
		vput(fdvp);
	if (xp)
		vput(fvp);
	vrele(ap->a_fvp);
	return (error);

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

/*
 * Mkdir system call
 */
static int
ext2_mkdir(ap)
	struct vop_mkdir_args /* {
		struct vnode *a_dvp;
		struct vnode **a_vpp;
		struct componentname *a_cnp;
		struct vattr *a_vap;
	} */ *ap;
{
	struct vnode *dvp = ap->a_dvp;
	struct vattr *vap = ap->a_vap;
	struct componentname *cnp = ap->a_cnp;
	struct inode *ip, *dp;
	struct vnode *tvp;
	struct dirtemplate dirtemplate, *dtp;
	int error, dmode;

#ifdef DIAGNOSTIC
	if ((cnp->cn_flags & HASBUF) == 0)
		panic("ext2_mkdir: no name");
#endif
	dp = VTOI(dvp);
	if ((nlink_t)dp->i_nlink >= LINK_MAX) {
		error = EMLINK;
		goto out;
	}
	dmode = vap->va_mode & 0777;
	dmode |= IFDIR;
	/*
	 * Must simulate part of ext2_makeinode here to acquire the inode,
	 * but not have it entered in the parent directory. The entry is
	 * made later after writing "." and ".." entries.
	 */
	error = ext2_valloc(dvp, dmode, cnp->cn_cred, &tvp);
	if (error)
		goto out;
	ip = VTOI(tvp);
	ip->i_gid = dp->i_gid;
#ifdef SUIDDIR
	{
		/*
		 * if we are hacking owners here, (only do this where told to)
		 * and we are not giving it TOO root, (would subvert quotas)
		 * then go ahead and give it to the other user.
		 * The new directory also inherits the SUID bit. 
		 * If user's UID and dir UID are the same,
		 * 'give it away' so that the SUID is still forced on.
		 */
		if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
		   (dp->i_mode & ISUID) && dp->i_uid) {
			dmode |= ISUID;
			ip->i_uid = dp->i_uid;
		} else {
			ip->i_uid = cnp->cn_cred->cr_uid;
		}
	}
#else
	ip->i_uid = cnp->cn_cred->cr_uid;
#endif
	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
	ip->i_mode = dmode;
	tvp->v_type = VDIR;	/* Rest init'd in getnewvnode(). */
	ip->i_nlink = 2;
	if (cnp->cn_flags & ISWHITEOUT)
		ip->i_flags |= UF_OPAQUE;
	error = ext2_update(tvp, 1);

	/*
	 * Bump link count in parent directory
	 * to reflect work done below.  Should
	 * be done before reference is created
	 * so reparation is possible if we crash.
	 */
	dp->i_nlink++;
	dp->i_flag |= IN_CHANGE;
	error = ext2_update(dvp, 1);
	if (error)
		goto bad;

	/* Initialize directory with "." and ".." from static template. */
	if (EXT2_HAS_INCOMPAT_FEATURE(ip->i_e2fs->s_es,
	    EXT2_FEATURE_INCOMPAT_FILETYPE))
		dtp = &mastertemplate;
	else
		dtp = &omastertemplate;
	dirtemplate = *dtp;
	dirtemplate.dot_ino = ip->i_number;
	dirtemplate.dotdot_ino = dp->i_number;
	/* note that in ext2 DIRBLKSIZ == blocksize, not DEV_BSIZE 
	 * so let's just redefine it - for this function only
	 */
#undef  DIRBLKSIZ 
#define DIRBLKSIZ  VTOI(dvp)->i_e2fs->s_blocksize
	dirtemplate.dotdot_reclen = DIRBLKSIZ - 12;
	error = vn_rdwr(UIO_WRITE, tvp, (caddr_t)&dirtemplate,
	    sizeof (dirtemplate), (off_t)0, UIO_SYSSPACE,
	    IO_NODELOCKED | IO_SYNC | IO_NOMACCHECK, cnp->cn_cred, NOCRED,
	    (int *)0, (struct thread *)0);
	if (error) {
		dp->i_nlink--;
		dp->i_flag |= IN_CHANGE;
		goto bad;
	}
	if (DIRBLKSIZ > VFSTOEXT2(dvp->v_mount)->um_mountp->mnt_stat.f_bsize)
		/* XXX should grow with balloc() */
		panic("ext2_mkdir: blksize");
	else {
		ip->i_size = DIRBLKSIZ;
		ip->i_flag |= IN_CHANGE;
	}

	/* Directory set up, now install its entry in the parent directory. */
	error = ext2_direnter(ip, dvp, cnp);
	if (error) {
		dp->i_nlink--;
		dp->i_flag |= IN_CHANGE;
	}
bad:
	/*
	 * No need to do an explicit VOP_TRUNCATE here, vrele will do this
	 * for us because we set the link count to 0.
	 */
	if (error) {
		ip->i_nlink = 0;
		ip->i_flag |= IN_CHANGE;
		vput(tvp);
	} else
		*ap->a_vpp = tvp;
out:
	return (error);
#undef  DIRBLKSIZ
#define DIRBLKSIZ  DEV_BSIZE
}

/*
 * Rmdir system call.
 */
static int
ext2_rmdir(ap)
	struct vop_rmdir_args /* {
		struct vnode *a_dvp;
		struct vnode *a_vp;
		struct componentname *a_cnp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct vnode *dvp = ap->a_dvp;
	struct componentname *cnp = ap->a_cnp;
	struct thread *td = cnp->cn_thread;
	struct inode *ip, *dp;
	int error;

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

	/*
	 * Verify the directory is empty (and valid).
	 * (Rmdir ".." won't be valid since
	 *  ".." will contain a reference to
	 *  the current directory and thus be
	 *  non-empty.)
	 */
	error = 0;
	if (ip->i_nlink != 2 || !ext2_dirempty(ip, dp->i_number, cnp->cn_cred)) {
		error = ENOTEMPTY;
		goto out;
	}
	if ((dp->i_flags & APPEND)
	    || (ip->i_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
		error = EPERM;
		goto out;
	}
	/*
	 * Delete reference to directory before purging
	 * inode.  If we crash in between, the directory
	 * will be reattached to lost+found,
	 */
	error = ext2_dirremove(dvp, cnp);
	if (error)
		goto out;
	dp->i_nlink--;
	dp->i_flag |= IN_CHANGE;
	cache_purge(dvp);
	VOP_UNLOCK(dvp, 0, td);
	/*
	 * Truncate inode.  The only stuff left
	 * in the directory is "." and "..".  The
	 * "." reference is inconsequential since
	 * we're quashing it.  The ".." reference
	 * has already been adjusted above.  We've
	 * removed the "." reference and the reference
	 * in the parent directory, but there may be
	 * other hard links so decrement by 2 and
	 * worry about them later.
	 */
	ip->i_nlink -= 2;
	error = ext2_truncate(vp, (off_t)0, IO_SYNC, cnp->cn_cred, td);
	cache_purge(ITOV(ip));
	vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, td);
out:
	return (error);
}

/*
 * symlink -- make a symbolic link
 */
static int
ext2_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 vnode *vp, **vpp = ap->a_vpp;
	struct inode *ip;
	int len, error;

	error = ext2_makeinode(IFLNK | ap->a_vap->va_mode, ap->a_dvp,
	    vpp, ap->a_cnp);
	if (error)
		return (error);
	vp = *vpp;
	len = strlen(ap->a_target);
	if (len < vp->v_mount->mnt_maxsymlinklen) {
		ip = VTOI(vp);
		bcopy(ap->a_target, (char *)ip->i_shortlink, len);
		ip->i_size = len;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	} else
		error = vn_rdwr(UIO_WRITE, vp, ap->a_target, len, (off_t)0,
		    UIO_SYSSPACE, IO_NODELOCKED | IO_NOMACCHECK,
		    ap->a_cnp->cn_cred, NOCRED, (int *)0, (struct thread *)0);
	if (error)
		vput(vp);
	return (error);
}

/*
 * Return target name of a symbolic link
 */
static int
ext2_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;
	struct inode *ip = VTOI(vp);
	int isize;

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

/*
 * Calculate the logical to physical mapping if not done already,
 * then call the device strategy routine.
 *
 * In order to be able to swap to a file, the ext2_bmaparray() operation may not
 * deadlock on memory.  See ext2_bmap() for details.
 */
static int
ext2_strategy(ap)
	struct vop_strategy_args /* {
		struct vnode *a_vp;
		struct buf *a_bp;
	} */ *ap;
{
	struct buf *bp = ap->a_bp;
	struct vnode *vp = ap->a_vp;
	struct inode *ip;
	struct bufobj *bo;
	int32_t blkno;
	int error;

	ip = VTOI(vp);
	if (vp->v_type == VBLK || vp->v_type == VCHR)
		panic("ext2_strategy: spec");
	if (bp->b_blkno == bp->b_lblkno) {
		error = ext2_bmaparray(vp, bp->b_lblkno, &blkno, NULL, NULL);
		bp->b_blkno = blkno;
		if (error) {
			bp->b_error = error;
			bp->b_ioflags |= BIO_ERROR;
			bufdone(bp);
			return (error);
		}
		if ((long)bp->b_blkno == -1)
			vfs_bio_clrbuf(bp);
	}
	if ((long)bp->b_blkno == -1) {
		bufdone(bp);
		return (0);
	}
	bp->b_iooffset = dbtob(bp->b_blkno);
	bo = VFSTOEXT2(vp->v_mount)->um_bo;
	BO_STRATEGY(bo, bp);
	return (0);
}

/*
 * Print out the contents of an inode.
 */
static int
ext2_print(ap)
	struct vop_print_args /* {
		struct vnode *a_vp;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct inode *ip = VTOI(vp);

	vn_printf(ip->i_devvp, "\tino %lu", (u_long)ip->i_number);
	if (vp->v_type == VFIFO)
		fifo_printinfo(vp);
	printf("\n");
	return (0);
}

/*
 * Close wrapper for fifos.
 *
 * Update the times on the inode then do device close.
 */
static int
ext2fifo_close(ap)
	struct vop_close_args /* {
		struct vnode *a_vp;
		int  a_fflag;
		struct ucred *a_cred;
		struct thread *a_td;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;

	VI_LOCK(vp);
	if (vp->v_usecount > 1)
		ext2_itimes(vp);
	VI_UNLOCK(vp);
	return (fifo_specops.vop_close(ap));
}

/*
 * Kqfilter wrapper for fifos.
 *
 * Fall through to ext2 kqfilter routines if needed 
 */
static int
ext2fifo_kqfilter(ap)
	struct vop_kqfilter_args *ap;
{
	int error;

	error = fifo_specops.vop_kqfilter(ap);
	if (error)
		error = ext2_kqfilter(ap);
	return (error);
}

/*
 * Return POSIX pathconf information applicable to ext2 filesystems.
 */
static int
ext2_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_NAME_MAX:
		*ap->a_retval = NAME_MAX;
		return (0);
	case _PC_PATH_MAX:
		*ap->a_retval = PATH_MAX;
		return (0);
	case _PC_PIPE_BUF:
		*ap->a_retval = PIPE_BUF;
		return (0);
	case _PC_CHOWN_RESTRICTED:
		*ap->a_retval = 1;
		return (0);
	case _PC_NO_TRUNC:
		*ap->a_retval = 1;
		return (0);
	default:
		return (EINVAL);
	}
	/* NOTREACHED */
}

/*
 * Advisory record locking support
 */
static int
ext2_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;
{
	struct inode *ip = VTOI(ap->a_vp);

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

/*
 * Initialize the vnode associated with a new inode, handle aliased
 * vnodes.
 */
int
ext2_vinit(mntp, fifoops, vpp)
	struct mount *mntp;
	struct vop_vector *fifoops;
	struct vnode **vpp;
{
	struct inode *ip;
	struct vnode *vp;

	vp = *vpp;
	ip = VTOI(vp);
	vp->v_type = IFTOVT(ip->i_mode);
	if (vp->v_type == VFIFO)
		vp->v_op = fifoops;

	if (ip->i_number == ROOTINO)
		vp->v_vflag |= VV_ROOT;
	ip->i_modrev = init_va_filerev();
	*vpp = vp;
	return (0);
}

/*
 * Allocate a new inode.
 */
static int
ext2_makeinode(mode, dvp, vpp, cnp)
	int mode;
	struct vnode *dvp;
	struct vnode **vpp;
	struct componentname *cnp;
{
	struct inode *ip, *pdir;
	struct vnode *tvp;
	int error;

	pdir = VTOI(dvp);
#ifdef DIAGNOSTIC
	if ((cnp->cn_flags & HASBUF) == 0)
		panic("ext2_makeinode: no name");
#endif
	*vpp = NULL;
	if ((mode & IFMT) == 0)
		mode |= IFREG;

	error = ext2_valloc(dvp, mode, cnp->cn_cred, &tvp);
	if (error) {
		return (error);
	}
	ip = VTOI(tvp);
	ip->i_gid = pdir->i_gid;
#ifdef SUIDDIR
	{
		/*
		 * if we are
		 * not the owner of the directory,
		 * and we are hacking owners here, (only do this where told to)
		 * and we are not giving it TOO root, (would subvert quotas)
		 * then go ahead and give it to the other user.
		 * Note that this drops off the execute bits for security.
		 */
		if ( (dvp->v_mount->mnt_flag & MNT_SUIDDIR) &&
		     (pdir->i_mode & ISUID) &&
		     (pdir->i_uid != cnp->cn_cred->cr_uid) && pdir->i_uid) {
			ip->i_uid = pdir->i_uid;
			mode &= ~07111;
		} else {
			ip->i_uid = cnp->cn_cred->cr_uid;
		}
	}
#else
	ip->i_uid = cnp->cn_cred->cr_uid;
#endif
	ip->i_flag |= IN_ACCESS | IN_CHANGE | IN_UPDATE;
	ip->i_mode = mode;
	tvp->v_type = IFTOVT(mode);	/* Rest init'd in getnewvnode(). */
	ip->i_nlink = 1;
	if ((ip->i_mode & ISGID) && !groupmember(ip->i_gid, cnp->cn_cred) &&
	    suser_cred(cnp->cn_cred, SUSER_ALLOWJAIL))
		ip->i_mode &= ~ISGID;

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

	/*
	 * Make sure inode goes to disk before directory entry.
	 */
	error = ext2_update(tvp, 1);
	if (error)
		goto bad;
	error = ext2_direnter(ip, dvp, cnp);
	if (error)
		goto bad;

	*vpp = tvp;
	return (0);

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

static struct filterops ext2read_filtops = 
	{ 1, NULL, filt_ext2detach, filt_ext2read };
static struct filterops ext2write_filtops = 
	{ 1, NULL, filt_ext2detach, filt_ext2write };
static struct filterops ext2vnode_filtops = 
	{ 1, NULL, filt_ext2detach, filt_ext2vnode };

static int
ext2_kqfilter(ap)
	struct vop_kqfilter_args /* {
		struct vnode *a_vp;
		struct knote *a_kn;
	} */ *ap;
{
	struct vnode *vp = ap->a_vp;
	struct knote *kn = ap->a_kn;

	switch (kn->kn_filter) {
	case EVFILT_READ:
		kn->kn_fop = &ext2read_filtops;
		break;
	case EVFILT_WRITE:
		kn->kn_fop = &ext2write_filtops;
		break;
	case EVFILT_VNODE:
		kn->kn_fop = &ext2vnode_filtops;
		break;
	default:
		return (1);
	}

	kn->kn_hook = (caddr_t)vp;

	if (vp->v_pollinfo == NULL)
		v_addpollinfo(vp);
	if (vp->v_pollinfo == NULL)
		return ENOMEM;
	knlist_add(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);

	return (0);
}

static void
filt_ext2detach(struct knote *kn)
{
	struct vnode *vp = (struct vnode *)kn->kn_hook;

	KASSERT(vp->v_pollinfo != NULL, ("Mising v_pollinfo"));
	knlist_remove(&vp->v_pollinfo->vpi_selinfo.si_note, kn, 0);
}

/*ARGSUSED*/
static int
filt_ext2read(struct knote *kn, long hint)
{
	struct vnode *vp = (struct vnode *)kn->kn_hook;
	struct inode *ip = VTOI(vp);

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

        kn->kn_data = ip->i_size - kn->kn_fp->f_offset;
        return (kn->kn_data != 0);
}

/*ARGSUSED*/
static int
filt_ext2write(struct knote *kn, long hint)
{

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

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

static int
filt_ext2vnode(struct knote *kn, long hint)
{

	if (kn->kn_sfflags & hint)
		kn->kn_fflags |= hint;
	if (hint == NOTE_REVOKE) {
		kn->kn_flags |= EV_EOF;
		return (1);
	}
	return (kn->kn_fflags != 0);
}
