From mboxrd@z Thu Jan 1 00:00:00 1970
From: bugzilla-daemon@bugzilla.kernel.org
Subject: [Bug 50981] ext4 : DATA CORRUPTION read and write on same 4096 page
range
Date: Mon, 26 Nov 2012 10:16:20 +0000 (UTC)
Message-ID: <20121126101620.32D0911FB81@bugzilla.kernel.org>
References:
Mime-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
To: linux-ext4@vger.kernel.org
Return-path:
Received: from mail.kernel.org ([198.145.19.201]:35381 "EHLO mail.kernel.org"
rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
id S1754829Ab2KZKQX (ORCPT );
Mon, 26 Nov 2012 05:16:23 -0500
Received: from mail.kernel.org (localhost [127.0.0.1])
by mail.kernel.org (Postfix) with ESMTP id D2E0D20207
for ; Mon, 26 Nov 2012 10:16:21 +0000 (UTC)
Received: from bugzilla.kernel.org (bugzilla.kernel.org [198.145.19.217])
by mail.kernel.org (Postfix) with ESMTP id 3CE1720203
for ; Mon, 26 Nov 2012 10:16:20 +0000 (UTC)
In-Reply-To:
Sender: linux-ext4-owner@vger.kernel.org
List-ID:
https://bugzilla.kernel.org/show_bug.cgi?id=50981
Zheng Liu changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |gnehzuil.liu@gmail.com
--- Comment #3 from Zheng Liu 2012-11-26 10:16:19 ---
IMHO, the reason seems to be that no any locking is taken by
generic_file_aio_read(). When ext4 does a buffered write, it will take i_mutex
to ensure that there is no other writer. But ext4 (ext3, btrfs, and vfat) uses
generic_file_aio_read() to do a buffered read, and it doesn't take i_mutex. So
it is easy to read a inconsistent data while doing a write. I am not very
familiar with xfs, but a rwlock will be taken when a read and/or a write is
being done. So that is why xfs hasn't this problem.
--
Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are watching the assignee of the bug.