Re: [RFC 0/4] Fix gfs2 readahead deadlocks

From: Andreas Gruenbacher
Date: Thu Jul 02 2020 - 14:23:22 EST


On Thu, Jul 2, 2020 at 8:11 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, Jul 2, 2020 at 9:51 AM Andreas Gruenbacher <agruenba@xxxxxxxxxx> wrote:
> >
> > Of this patch queue, either only the first patch or all four patches can
> > be applied to fix gfs2's current issues in 5.8. Please let me know what
> > you think.
>
> I think the IOCB_NOIO flag looks fine (apart from the nit I pointed
> out), and we could do that.

Ok, that's a step forward.

> However, is the "revert and reinstate" looks odd. Is the reinstate so
> different from the original that it makes sense to do that way?
>
> Or was it done that way only to give the choice of just doing the revert?
>
> Because if so, I think I'd rather just see a "fix" rather than
> "revert+reinstate".

I only did the "revert and reinstate" so that the revert alone will
give us a working gfs2 in 5.8. If there's agreement to add the
IOCB_NOIO flag, then we can just fix gfs2 (basically
https://lore.kernel.org/linux-fsdevel/20200619093916.1081129-3-agruenba@xxxxxxxxxx/
with IOCB_CACHED renamed to IOCB_NOIO).

Thanks,
Andreas