Re: [PATCH] xfs: new EOF fragmentation tests

Dave Chinner
2019-02-11T01:55:43Z

On Mon, Feb 11, 2019 at 12:36:47PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> These tests create substantial file fragmentation as a result of
> application actions that defeat post-EOF preallocation
> optimisations. They are intended to replicate known vectors for
> these problems, and provide a check that the fragmentation levels
> have been controlled. The mitigations we make may not completely
> remove fragmentation (e.g. they may demonstrate speculative delalloc
> related extent size growth) so the checks don't assume we'll end up
> with perfect layouts and hence check for an exceptable level of
> fragmentation rather than none.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> ---

Forgot to add that these tests go along with this patch series:

https://marc.info/?l=linux-xfs&m=154951612101291&w=2

And can be used to test whatever way we decide to minimise
fragmentation through maintianing post-EOF preallocation.

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com