From: "Mike Snitzer" <snitzer@gmail.com>
Subject: Re: [PATCH 1/2] ext3: add an option to control error handling on file data
Date: Wed, 30 Jul 2008 11:14:02 -0400
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To: "Hidehiro Kawai" <hidehiro.kawai.ez@hitachi.com>
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On Tue, Jul 29, 2008 at 10:52 PM, Hidehiro Kawai
<hidehiro.kawai.ez@hitachi.com> wrote:
> If the journal doesn't abort when it gets an IO error in file data
> blocks, the file data corruption will spread silently.  Because
> most of applications and commands do buffered writes without fsync(),
> they don't notice the IO error.  It's scary for mission critical
> systems.  On the other hand, if the journal aborts whenever it gets
> an IO error in file data blocks, the system will easily become
> inoperable.  So this patch introduces a filesystem option to
> determine whether it aborts the journal or just call printk() when
> it gets an IO error in file data.
>
> If you mount a ext3 fs with data_err=abort option, it aborts on file
> data write error.  If you mount it with data_err=ignore, it doesn't
> abort, just call printk().  data_err=abort is default, because
> people have used this error handling policy for three years.

Hidehiro,

Thanks for making this configurable!

But given how surprised many of us were when we found out that
jbd/ext3 has been aborting on file data blocks isn't this our chance
to correct that long-standing oversight?  Shouldn't the default be
data_err=ignore?  Or would changing this behavior cause more harm than
good?

I don't feel strongly either way, having the "data_err" option makes
this issue moot for me, but I figured I'd raise the question (in the
interest of review).

Mike