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, info: &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, last_written: &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

source code of linux/fs/udf/lowlevel.c