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 "udf_sb.h"
27 
udf_get_last_session(struct super_block * sb)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 
udf_get_last_block(struct super_block * sb)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 = bdev->bd_inode->i_size >> sb->s_blocksize_bits;
62 
63 	if (lblock)
64 		return lblock - 1;
65 	else
66 		return 0;
67 }
68