From: Theodore Ts'o <tytso@mit.edu>
To: Jan Kara <jack@suse.cz>
Cc: linux-ext4@vger.kernel.org
Subject: Re: ext4: Forbid journal_async_commit in data=ordered mode
Date: Tue, 25 Nov 2014 20:20:02 -0500 [thread overview]
Message-ID: <20141126012002.GA28130@thunk.org> (raw)
In-Reply-To: <1416930975-13676-1-git-send-email-jack@suse.cz>
On Tue, Nov 25, 2014 at 04:56:15PM +0100, Jan Kara wrote:
> Option journal_async_commit breaks gurantees of data=ordered mode as it
> sends only a single cache flush after writing a transaction commit
> block. Thus even though the transaction including the commit block is
> fully stored on persistent storage, file data may still linger in drives
> caches and will be lost on power failure. Since all checksums match on
> journal recovery, we replay the transaction thus possibly exposing stale
> user data.
>
> To fix this data exposure issue, remove the possibility to use
> journal_async_commit in data=ordered mode.
>
> Signed-off-by: Jan Kara <jack@suse.cz>
Applied, thanks.
- Ted
next prev parent reply other threads:[~2014-11-26 1:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-25 15:56 [PATCH] ext4: Forbid journal_async_commit in data=ordered mode Jan Kara
2014-11-26 1:20 ` Theodore Ts'o [this message]
2014-12-24 7:31 ` alex chen
2014-12-29 19:19 ` Jan Kara
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