WSL2-Linux-Kernel/fs/udf/lowlevel.c

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1.5 KiB
C
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/*
* lowlevel.c
*
* PURPOSE
* Low Level Device Routines for the UDF filesystem
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1999-2001 Ben Fennema
*
* HISTORY
*
* 03/26/99 blf Created.
*/
#include "udfdecl.h"
#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <linux/uaccess.h>
#include "udf_sb.h"
unsigned int udf_get_last_session(struct super_block *sb)
{
struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
struct cdrom_multisession ms_info;
if (!cdi) {
udf_debug("CDROMMULTISESSION not supported.\n");
return 0;
}
ms_info.addr_format = CDROM_LBA;
if (cdrom_multisession(cdi, &ms_info) == 0) {
udf_debug("XA disk: %s, vol_desc_start=%d\n",
ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
return ms_info.addr.lba;
}
return 0;
}
unsigned long udf_get_last_block(struct super_block *sb)
{
struct block_device *bdev = sb->s_bdev;
struct cdrom_device_info *cdi = disk_to_cdi(bdev->bd_disk);
unsigned long lblock = 0;
/*
* The cdrom layer call failed or returned obviously bogus value?
* Try using the device size...
*/
if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0)
lblock = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;
if (lblock)
return lblock - 1;
return 0;
}