lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue, 26 Apr 2011 08:25:58 -0400
From:	Ted Ts'o <tytso@....edu>
To:	Ding Dinghua <dingdinghua85@...il.com>
Cc:	Yongqiang Yang <xiaoqiangnk@...il.com>,
	Niraj Kulkarni <kulkarniniraj14@...il.com>,
	linux-ext4@...r.kernel.org
Subject: Re: Need of revoke mechanism in JBD

On Tue, Apr 26, 2011 at 05:23:21PM +0800, Ding Dinghua wrote:
> I think it's not only a performance issue but more important, a
> correctness issue.
> Revoke table is used for preventing the wrong replay of journal which
> cause data corruption:
> If block A has been journalled its modification, committed to journal
> and hasn't been checkpointed,
> and in later transactions block A is freed and reused for data in
> no-journalled-data mode, then If
> we don't have revoke table which recording the releasing event, replay
> of journal will overwrite the new data,
> which causing data corruption.

Yes, this is correct.  It should be covered fairly well in Stephen
Tweedie's, "Journaling the ext2fs file system" paper, which you can
find at:

https://ext4.wiki.kernel.org/index.php/Publications

if you'd like more details.

Hope this helps!

						- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists