root/fs/udf/lowlevel.c

DEFINITIONS

1. udf_get_last_session
2. udf_get_last_block

/*
 * 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 <asm/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);

#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;
}