lowlevel.c
/*
* lowlevel.c
*
* PURPOSE
* Low Level Device Routines for the UDF filesystem
*
* CONTACTS
* E-mail regarding any portion of the Linux UDF file system should be
* directed to the development team mailing list (run by majordomo):
* linux_udf@hpesjro.fc.hp.com
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1999-2001 Ben Fennema
*
* HISTORY
*
* 03/26/99 blf Created.
*/
#include "udfdecl.h"
#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <asm/uaccess.h>
#include <linux/udf_fs.h>
#include "udf_sb.h"
unsigned int
udf_get_last_session(struct super_block *sb)
{
struct cdrom_multisession ms_info;
unsigned int vol_desc_start;
struct block_device *bdev = sb->s_bdev;
int i;
vol_desc_start=0;
ms_info.addr_format=CDROM_LBA;
i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long) &ms_info);
#define WE_OBEY_THE_WRITTEN_STANDARDS 1
if (i == 0)
{
udf_debug("XA disk: %s, vol_desc_start=%d\n",
(ms_info.xa_flag ? "yes" : "no"), ms_info.addr.lba);
#if WE_OBEY_THE_WRITTEN_STANDARDS
if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
#endif
vol_desc_start = ms_info.addr.lba;
}
else
{
udf_debug("CDROMMULTISESSION not supported: rc=%d\n", i);
}
return vol_desc_start;
}
unsigned long
udf_get_last_block(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
unsigned long lblock = 0;
if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock))
lblock = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
if (lblock)
return lblock - 1;
else
return 0;
}