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Revision 8cde7ad17e4f4ff8d12ff60dd09c0a291cb0b61c authored by Zheng Liu on 03 April 2013, 16:27:18 UTC, committed by Theodore Ts'o on 03 April 2013, 16:37:17 UTC 
ext4: fix big-endian bugs which could cause fs corruptions
 
When an extent was zeroed out, we forgot to do convert from cpu to le16.
It could make us hit a BUG_ON when we try to write dirty pages out.  So
fix it.

[ Also fix a bug found by Dmitry Monakhov where we were missing
  le32_to_cpu() calls in the new indirect punch hole code.

  There are a number of other big endian warnings found by static code
  analyzers, but we'll wait for the next merge window to fix them all
  up.  These fixes are designed to be Obviously Correct by code
  inspection, and easy to demonstrate that it won't make any
  difference (and hence, won't introduce any bugs) on little endian
  architectures such as x86.  --tytso ]

Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: CAI Qian <caiqian@redhat.com>
Reported-by: Christian Kujau <lists@nerdbynature.de>
Cc: Dmitry Monakhov <dmonakhov@openvz.org>
1 parent 07961ac
Raw File
lowlevel.c 
/*
 * 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 <asm/uaccess.h>

#include "udf_sb.h"

unsigned int udf_get_last_session(struct super_block *sb)
{
	struct cdrom_multisession ms_info;
	unsigned int vol_desc_start;
	struct block_device *bdev = sb->s_bdev;
	int i;

	vol_desc_start = 0;
	ms_info.addr_format = CDROM_LBA;
	i = ioctl_by_bdev(bdev, CDROMMULTISESSION, (unsigned long)&ms_info);

	if (i == 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 */
			vol_desc_start = ms_info.addr.lba;
	} else {
		udf_debug("CDROMMULTISESSION not supported: rc=%d\n", i);
	}
	return vol_desc_start;
}

unsigned long udf_get_last_block(struct super_block *sb)
{
	struct block_device *bdev = sb->s_bdev;
	unsigned long lblock = 0;

	/*
	 * ioctl failed or returned obviously bogus value?
	 * Try using the device size...
	 */
	if (ioctl_by_bdev(bdev, CDROM_LAST_WRITTEN, (unsigned long) &lblock) ||
	    lblock == 0)
		lblock = bdev->bd_inode->i_size >> sb->s_blocksize_bits;

	if (lblock)
		return lblock - 1;
	else
		return 0;
}
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