Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-cpufreq-sched'
[linux-2.6-microblaze.git] / fs / udf / lowlevel.c
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 <linux/uaccess.h>
25
26 #include "udf_sb.h"
27
28 unsigned 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
50 unsigned 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 = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;
62
63         if (lblock)
64                 return lblock - 1;
65         else
66                 return 0;
67 }