Re: [PATCH -mm] fault-injection: reject-failure-if-any-caller-lies-within-specified range

From: Akinobu Mita
Date: Mon Nov 20 2006 - 14:58:30 EST


On Mon, Nov 20, 2006 at 11:24:22AM -0800, Don Mullis wrote:
> > This test is a little intentional.
> > (Normal I/O may fail, but journal commit I/O doesn't fail)
>
> I'm not sure in what sense the test could be called "intentional".

Because make_fault_request just injects failures randomly. there is no
difference between normal I/O and journal commit I/O.

The problem is the make_fault_request doesn't have clever setting such as
md/faulty module can simulate broken sectors.

> The patch raises the default stacktrace-depth from 10 to 32, and
> although there is indeed no guarantee this is enough, in practice I
> found the filesystem became hopelessly scrambled before ever hitting one
> of the kjournald cases again.

You can set /debug/fail_make_request/times smaller value so that
you can see what happened in filesystem before kjournald hits failure.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/