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Date: Tue, 10 Mar 2009 17:34:37 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Valdis.Kletnieks@vt.edu
Cc: porte64@free.fr, linux-kernel@vger.kernel.org
Subject: Re: read-only partitions: does the policy apply to all metadata ?
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On Tue, 10 Mar 2009 13:22:39 -0400
Valdis.Kletnieks@vt.edu wrote:

> On Tue, 10 Mar 2009 17:26:44 BST, porte64@free.fr said:
> > When a partition is mounted as read-only, does the kernel
> > really prevent ANY byte to be written to it, including
> > any metadata ?
> 
> It's very hard to come up with a workable way to do a true read-only
> mount of a journaled filesystem such as ext3 - what do you do if there's
> anything in the journal that needs to be replayed?

Replay it to a snapshot backed by the r/o fs ...