[PATCH] ext4: 48bit physical block number support in extents
[linux-2.6] / 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 <asm/uaccess.h>
25
26 #include <linux/udf_fs.h>
27 #include "udf_sb.h"
28
29 unsigned int 
30 udf_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
59 unsigned long
60 udf_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 }