1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * lowlevel.c
4 *
5 * PURPOSE
6 *  Low Level Device Routines for the UDF filesystem
7 *
8 * COPYRIGHT
9 *  (C) 1999-2001 Ben Fennema
10 *
11 * HISTORY
12 *
13 *  03/26/99 blf  Created.
14 */
15
16#include "udfdecl.h"
17
18#include <linux/blkdev.h>
19#include <linux/cdrom.h>
20#include <linux/uaccess.h>
21
22#include "udf_sb.h"
23
24unsigned int udf_get_last_session(struct super_block *sb)
25{
26	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
27	struct cdrom_multisession ms_info;
28
29	if (!cdi) {
30		udf_debug("CDROMMULTISESSION not supported.\n");
31		return 0;
32	}
33
34	ms_info.addr_format = CDROM_LBA;
35	if (cdrom_multisession(cdi, &ms_info) == 0) {
36		udf_debug("XA disk: %s, vol_desc_start=%d\n",
37			  ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
38		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
39			return ms_info.addr.lba;
40	}
41	return 0;
42}
43
44udf_pblk_t udf_get_last_block(struct super_block *sb)
45{
46	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
47	unsigned long lblock = 0;
48
49	/*
50	 * The cdrom layer call failed or returned obviously bogus value?
51	 * Try using the device size...
52	 */
53	if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0) {
54		if (sb_bdev_nr_blocks(sb) > ~(udf_pblk_t)0)
55			return 0;
56		lblock = sb_bdev_nr_blocks(sb);
57	}
58
59	if (lblock)
60		return lblock - 1;
61	return 0;
62}
63