Re: [RFC, PATCH 0/6] ext3: do not modify data on-disk when mounting read-only filesystem

Andrew Morton
2008-03-06T03:43:57Z

On Thu, 6 Mar 2008 01:59:08 +0000 "Duane Griffin" <duaneg@dghda.com> wrote:

> At present, as discussed in this LKML thread,
> http://marc.info/?l=linux-kernel&m=117607695406580, when a dirty ext3
> filesystem is mounted read-only it writes to the disk while replaying the
> journal log and cleaning up the orphan list. This behaviour may surprise users
> and can potentially cause data corruption/loss (e.g. if a system is suspended,
> booted into a different OS, then resumed).
>
> This patch series attempts to address this by using a block translation table
> instead of replaying the journal on a read-only filesystem.
>
> Patches 1-3 are independent cleanups/bug-fixes for things I came across while
> working on this. They could be submitted separately and are not required for
> following patches.
>
> Patch 4 is a refactoring change that simplifies the code prior to later
> substantive changes.
>
> Patch 5 introduces the translation table and support for a truly read-only
> journal into jbd.
>
> Patch 6 uses the facility introduced in patch 5 to add support for true
> read-only ext3.

I'll grab the first three for now, thanks.

Someone(tm) should do the jbd2 versions..