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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * lowlevel.c
3 *
4 * PURPOSE
5 * Low Level Device Routines for the UDF filesystem
6 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * 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 <linux/udf_fs.h>
27#include "udf_sb.h"
28
29unsigned int
30udf_get_last_session(struct super_block *sb)
31{
32 struct cdrom_multisession ms_info;
33 unsigned int vol_desc_start;
34 struct block_device *bdev = sb->s_bdev;
35 int i;
36
37 vol_desc_start=0;
38 ms_info.addr_format=CDROM_LBA;
39 i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long) &ms_info);
40
41#define WE_OBEY_THE_WRITTEN_STANDARDS 1
42
43 if (i == 0)
44 {
45 udf_debug("XA disk: %s, vol_desc_start=%d\n",
46 (ms_info.xa_flag ? "yes" : "no"), ms_info.addr.lba);
47#if WE_OBEY_THE_WRITTEN_STANDARDS
48 if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
49#endif
50 vol_desc_start = ms_info.addr.lba;
51 }
52 else
53 {
54 udf_debug("CDROMMULTISESSION not supported: rc=%d\n", i);
55 }
56 return vol_desc_start;
57}
58
59unsigned long
60udf_get_last_block(struct super_block *sb)
61{
62 struct block_device *bdev = sb->s_bdev;
63 unsigned long lblock = 0;
64
65 if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock))
66 lblock = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
67
68 if (lblock)
69 return lblock - 1;
70 else
71 return 0;
72}