linux-kernel - Re: [PATCH v5 1/1] Allow non-extending parallel direct writes on the same file.

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Message-ID: <CAJfpegtRzDbcayn7MYKpgO1MBFeBihyfRB402JHtJkbXg1dvLg@mail.gmail.com>
Date:   Fri, 17 Jun 2022 09:36:10 +0200
From:   Miklos Szeredi <miklos@...redi.hu>
To:     Dharmendra Singh <dharamhans87@...il.com>
Cc:     Vivek Goyal <vgoyal@...hat.com>, linux-fsdevel@...r.kernel.org,
        fuse-devel <fuse-devel@...ts.sourceforge.net>,
        linux-kernel@...r.kernel.org, Bernd Schubert <bschubert@....com>,
        Dharmendra Singh <dsingh@....com>
Subject: Re: [PATCH v5 1/1] Allow non-extending parallel direct writes on the
 same file.

On Fri, 17 Jun 2022 at 09:10, Dharmendra Singh <dharamhans87@...il.com> wrote:

> This patch relaxes the exclusive lock for direct non-extending writes
> only. File size extending writes might not need the lock either,
> but we are not entirely sure if there is a risk to introduce any
> kind of regression. Furthermore, benchmarking with fio does not
> show a difference between patch versions that take on file size
> extension a) an exclusive lock and b) a shared lock.

I'm okay with this, but ISTR Bernd noted a real-life scenario where
this is not sufficient.  Maybe that should be mentioned in the patch
header?

Thanks,
Miklos