Re: ReiserFS data corruption in very simple configuration

Stephen C. Tweedie
2001-10-03T16:14:41Z

Hi,

On Sun, Sep 30, 2001 at 08:38:31PM -0700, Mike Fedyk wrote:

> >From what you're describing, it looks like the contents of test after a
> truncate won't be overwritten by another transaction until the deletion of
> those blocks has made it to disk... So, while in ordered, or journal mode,
> I'd end up with "a" in test, but with writeback mode there is no such
> guarantee.
>
> Am I missing something?
>
> Are there any known cases where ext3 will not be able to recover pervious
> data when a write wasn't able to complete?

It depends on what the application is doing. Applications often open
an existing file with O_TRUNC, write to it, then close it. If you
crash between the truncate and the write being committed, then you'll
get a perfectly legal, sane, consistent, empty file on recovery.

--Stephen