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/*
* lowlevel.c
*
* PURPOSE
* Low Level Device Routines for the UDF filesystem
*
* 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 <linux/uaccess.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);
if (i == 0) {
udf_debug("XA disk: %s, vol_desc_start=%d\n",
ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
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;
/*
* ioctl failed or returned obviously bogus value?
* Try using the device size...
*/
if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock) ||
lblock == 0)
lblock = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;
if (lblock)
return lblock - 1;
else
return 0;
}
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