/*
 * Copyright (c) 1992, 1993, 1995
 *	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
 *
 * $FreeBSD: src/sys/miscfs/fdesc/fdesc_vfsops.c,v 1.22.2.3 2002/08/23 17:42:39 njl Exp $
 * $DragonFly: src/sys/vfs/fdesc/fdesc_vfsops.c,v 1.22 2006/09/05 00:55:50 dillon Exp $
 */

/*
 * /dev/fd Filesystem
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/filedesc.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/socket.h>
#include <sys/vnode.h>

#include "fdesc.h"

extern struct vop_ops fdesc_vnode_vops;

static MALLOC_DEFINE(M_FDESCMNT, "FDESC mount", "FDESC mount structure");

static int	fdesc_mount (struct mount *mp, char *path, caddr_t data,
				struct ucred *cred);
static int	fdesc_unmount (struct mount *mp, int mntflags);
static int	fdesc_statfs (struct mount *mp, struct statfs *sbp,
				struct ucred *cred);
  
/*
 * Mount the per-process file descriptors (/dev/fd)
 */
static int
fdesc_mount(struct mount *mp, char *path, caddr_t data, struct ucred *cred)
{
	int error = 0;
	struct fdescmount *fmp;
	struct vnode *rvp;

	if (path == NULL)
		panic("fdesc_mount: cannot mount as root");

	/*
	 * Update is a no-op
	 */
	if (mp->mnt_flag & MNT_UPDATE)
		return (EOPNOTSUPP);

	vfs_add_vnodeops(mp, &fdesc_vnode_vops, &mp->mnt_vn_norm_ops);

	error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
	if (error)
		return (error);

	MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
				M_FDESCMNT, 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;
	vfs_getnewfsid(mp);

	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
	bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
	fdesc_statfs(mp, &mp->mnt_stat, cred);
	return (0);
}

static int
fdesc_unmount(struct mount *mp, int mntflags)
{
	int error;
	int flags = 0;

	if (mntflags & MNT_FORCE)
		flags |= FORCECLOSE;

	/*
	 * Clear out buffer cache.  I don't think we
	 * ever get anything cached at this level at the
	 * moment, but who knows...
	 *
	 * There is 1 extra root vnode reference corresponding
	 * to f_root.
	 */
	if ((error = vflush(mp, 1, flags)) != 0)
		return (error);

	/*
	 * Finally, throw away the fdescmount structure
	 */
	kfree(mp->mnt_data, M_FDESCMNT);	/* XXX */
	mp->mnt_data = 0;

	return (0);
}

int
fdesc_root(struct mount *mp, struct vnode **vpp)
{
	struct vnode *vp;
	int error;

	/*
	 * Return locked reference to root.
	 */
	vp = VFSTOFDESC(mp)->f_root;
	error = vget(vp, LK_EXCLUSIVE | LK_RETRY);
	if (error == 0)
		*vpp = vp;
	return (error);
}

static int
fdesc_statfs(struct mount *mp, struct statfs *sbp, struct ucred *cred)
{
	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;		/* dummy up these fields */
	sbp->f_ffree = 0;
	if (sbp != &mp->mnt_stat) {
		sbp->f_type = mp->mnt_vfc->vfc_typenum;
		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
	}
	return (0);
}

static struct vfsops fdesc_vfsops = {
	.vfs_mount =    	fdesc_mount,
	.vfs_unmount =  	fdesc_unmount,
	.vfs_root =     	fdesc_root,
	.vfs_statfs =   	fdesc_statfs,
	.vfs_sync =     	vfs_stdsync,
	.vfs_init =     	fdesc_init,
	.vfs_uninit =   	fdesc_uninit
};

VFS_SET(fdesc_vfsops, fdesc, VFCF_SYNTHETIC);