Re: ReiserFS / 2.4.6 / Data Corruption

Christoph Hellwig (hch@caldera.de)
Tue, 31 Jul 2001 00:50:49 +0200


On Mon, Jul 30, 2001 at 03:41:16PM -0700, Kip Macy wrote:
> How does compiling in debug infrastructure protect the user's data? By
> making the file system so slow that he won't use it? :-)

The <<reiserfs debugging code>> isn't debugging code in a strict sense.
It mostly it consists of sequences in the form of:

(sometimes there is also code that the documentation states as deadlock-
avoidance, why it is not enabled without _CHECK defined is left as
exercise to the reader)

#ifdef CONFIG_REISERFS_CHECK
if (condition_that_should_not_happen)
reiserfs_panic (sb, "some_obscure_error_code");
#endif

This way the system stops with a indication of the failing component
instead of silently corrupting disk contents. As reiserfs maintains
a log the recovery from that panic shouldn't take that long either.

(On the other hand I've seen some reiserfs systems that destroyed their
disk contents while trying to recover. That's a reason why I still
can't recomend using reiserfs for anything but /tmp, test machines
or proxy caches).

Christoph

-- 
Of course it doesn't work. We've performed a software upgrade.
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