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 <20230220193754.470330-8-aleksandr.mikhalitsyn@canonical.com> <381a19bb-d17e-b48b-8259-6287dbe170df@fastmail.fm>
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From:   Aleksandr Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Date:   Mon, 6 Mar 2023 15:09:31 +0100
Message-ID: <CAEivzxf8HKs2FJwTohzGVcb0TRNy9QJbEALC3dni3zx+tOb9Gg@mail.gmail.com>
Subject: Re: [RFC PATCH 7/9] fuse: add fuse device ioctl(FUSE_DEV_IOC_REINIT)
To:     Bernd Schubert <bernd.schubert@fastmail.fm>
Cc:     mszeredi@redhat.com, Al Viro <viro@zeniv.linux.org.uk>,
        Amir Goldstein <amir73il@gmail.com>,
        =?UTF-8?Q?St=C3=A9phane_Graber?= <stgraber@ubuntu.com>,
        Seth Forshee <sforshee@kernel.org>,
        Christian Brauner <brauner@kernel.org>,
        Andrei Vagin <avagin@gmail.com>,
        Pavel Tikhomirov <ptikhomirov@virtuozzo.com>,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        criu@openvz.org
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On Fri, Mar 3, 2023 at 8:26=E2=80=AFPM Bernd Schubert
<bernd.schubert@fastmail.fm> wrote:
>
>
>
> On 2/20/23 20:37, Alexander Mikhalitsyn wrote:
> > This ioctl aborts fuse connection and then reinitializes it,
> > sends FUSE_INIT request to allow a new userspace daemon
> > to pick up the fuse connection.
> >
> > Cc: Miklos Szeredi <mszeredi@redhat.com>
> > Cc: Al Viro <viro@zeniv.linux.org.uk>
> > Cc: Amir Goldstein <amir73il@gmail.com>
> > Cc: St=C3=83=C2=A9phane Graber <stgraber@ubuntu.com>
> > Cc: Seth Forshee <sforshee@kernel.org>
> > Cc: Christian Brauner <brauner@kernel.org>
> > Cc: Andrei Vagin <avagin@gmail.com>
> > Cc: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
> > Cc: linux-fsdevel@vger.kernel.org
> > Cc: linux-kernel@vger.kernel.org
> > Cc: criu@openvz.org
> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.c=
om>
> > ---
> >   fs/fuse/dev.c             | 132 +++++++++++++++++++++++++++++++++++++=
+
> >   include/uapi/linux/fuse.h |   1 +
> >   2 files changed, 133 insertions(+)
> >
> > diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
> > index 737764c2295e..0f53ffd63957 100644
> > --- a/fs/fuse/dev.c
> > +++ b/fs/fuse/dev.c
> > @@ -2187,6 +2187,112 @@ void fuse_abort_conn(struct fuse_conn *fc)
> >   }
> >   EXPORT_SYMBOL_GPL(fuse_abort_conn);
> >
> > +static int fuse_reinit_conn(struct fuse_conn *fc)
> > +{
> > +     struct fuse_iqueue *fiq =3D &fc->iq;
> > +     struct fuse_dev *fud;
> > +     unsigned int i;
> > +
> > +     if (fc->conn_gen + 1 < fc->conn_gen)
> > +             return -EOVERFLOW;
> > +
> > +     fuse_abort_conn(fc);
> > +     fuse_wait_aborted(fc);
>
> Shouldn't this also try to flush all data first?

I think we should. Thanks for pointing to that!

I've read all your comments and I'll prepare -v2 series soon.

Thanks a lot, Bernd!

>