1/*
2 * lowlevel.c
3 *
4 * PURPOSE
5 *  Low Level Device Routines for the UDF filesystem
6 *
7 * COPYRIGHT
8 *	This file is distributed under the terms of the GNU General Public
9 *	License (GPL). Copies of the GPL can be obtained from:
10 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
11 *	Each contributing author retains all rights to their own work.
12 *
13 *  (C) 1999-2001 Ben Fennema
14 *
15 * HISTORY
16 *
17 *  03/26/99 blf  Created.
18 */
19
20#include "udfdecl.h"
21
22#include <linux/blkdev.h>
23#include <linux/cdrom.h>
24#include <asm/uaccess.h>
25
26#include "udf_sb.h"
27
28unsigned int udf_get_last_session(struct super_block *sb)
29{
30	struct cdrom_multisession ms_info;
31	unsigned int vol_desc_start;
32	struct block_device *bdev = sb->s_bdev;
33	int i;
34
35	vol_desc_start = 0;
36	ms_info.addr_format = CDROM_LBA;
37	i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long)&ms_info);
38
39	if (i == 0) {
40		udf_debug("XA disk: %s, vol_desc_start=%d\n",
41			  (ms_info.xa_flag ? "yes" : "no"), ms_info.addr.lba);
42		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
43			vol_desc_start = ms_info.addr.lba;
44	} else {
45		udf_debug("CDROMMULTISESSION not supported: rc=%d\n", i);
46	}
47	return vol_desc_start;
48}
49
50unsigned long udf_get_last_block(struct super_block *sb)
51{
52	struct block_device *bdev = sb->s_bdev;
53	unsigned long lblock = 0;
54
55	/*
56	 * ioctl failed or returned obviously bogus value?
57	 * Try using the device size...
58	 */
59	if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock) ||
60	    lblock == 0)
61		lblock = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
62
63	if (lblock)
64		return lblock - 1;
65	else
66		return 0;
67}
68