/*
 * device.c - Low level device io functions. Part of the Linux-NTFS project.
 *
 * Copyright (c) 2003 Anton Altaparmakov
 *
 * This program/include file is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as published
 * by the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program/include file is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (in the main directory of the Linux-NTFS
 * distribution in the file COPYING); if not, write to the Free Software
 * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "config.h"

#include <stdlib.h>
#include <errno.h>

#include "device.h"

/**
 * ntfs_device_alloc - allocate an ntfs device structure and pre-initialize it
 *
 * Allocate an ntfs device structure and pre-initialize it.
 *
 * On success return a pointer to the allocated ntfs device structure and on
 * error return NULL with errno set to the error code returned by malloc().
 */
struct ntfs_device *ntfs_device_alloc(void)
{
	struct ntfs_device *dev;

	dev = (struct ntfs_device *)malloc(sizeof(struct ntfs_device));
	if (dev) {
		dev->d_ops = NULL;
		dev->d_state = 0;
		dev->d_name = NULL;
		dev->d_private = NULL;
	}
	return dev;
}

/**
 * ntfs_device_free - free an ntfs device structure
 * @dev:	ntfs device structure to free
 *
 * Free the ntfs device structure @dev.
 *
 * Return 0 on success or -1 on error with errno set to the error code. The
 * following error codes are defined:
 *	EINVAL		Invalid pointer @dev.
 *	EBUSY		Device is still open. Close it before freeing it!
 */
int ntfs_device_free(struct ntfs_device *dev)
{
	if (!dev) {
		errno = EINVAL;
		return -1;
	}
	if (NDevOpen(dev)) {
		errno = EBUSY;
		return -1;
	}
	free(dev);
	return 0;
}