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Message-ID: <4b0b46f29955956916765d8d615f96849c8ce3f7.camel@linaro.org>
Subject: Re: [PATCH v2] Revert "fuse: Apply flags2 only when userspace set
 the FUSE_INIT_EXT"
From:   =?ISO-8859-1?Q?Andr=E9?= Draszik <andre.draszik@linaro.org>
To:     Bernd Schubert <bschubert@ddn.com>
Cc:     Miklos Szeredi <mszeredi@redhat.com>,
        "stable@vger.kernel.org" <stable@vger.kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Date:   Wed, 18 Oct 2023 12:46:13 +0100
In-Reply-To: <717fd97a-6d14-4dc9-808c-d752d718fb80@ddn.com>
References: <20230904133321.104584-1-git@andred.net>
         <20231018111508.3913860-1-git@andred.net>
         <717fd97a-6d14-4dc9-808c-d752d718fb80@ddn.com>
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On Wed, 2023-10-18 at 11:39 +0000, Bernd Schubert wrote:
> On 10/18/23 13:15, Andr=C3=A9 Draszik wrote:
> > From: Andr=C3=A9 Draszik <andre.draszik@linaro.org>
> >=20
> > This reverts commit 3066ff93476c35679cb07a97cce37d9bb07632ff.
> >=20
> > This patch breaks all existing userspace by requiring updates as
> > mentioned in the commit message, which is not allowed.
> >=20
> > Revert to restore compatibility with existing userspace
> > implementations.
>=20
> Which fuse file system does it exactly break? In fact there haven't
> been=20
> added too many flags after - what exactly is broken?

The original patch broke the existing kernel <-> user ABI by now
requiring user space applications to pass in an extra flag.
There are various side-effects of this, like unbootable systems, just
because the kernel was updated.
Breaking the ABI is the one thing that is not allowed. This is not
specific to any particular fuse file system.

Kind Regards,
Andre