From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60545) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bMsM2-0007fb-Ao for qemu-devel@nongnu.org; Tue, 12 Jul 2016 03:43:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bMsLx-0005OL-C9 for qemu-devel@nongnu.org; Tue, 12 Jul 2016 03:43:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53572) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bMsLx-0005OE-4O for qemu-devel@nongnu.org; Tue, 12 Jul 2016 03:43:37 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 8B057C00FBB4 for ; Tue, 12 Jul 2016 07:43:34 +0000 (UTC) References: <20160711144847.16651-1-marcandre.lureau@redhat.com> From: Jason Wang Message-ID: <57849FA1.3050705@redhat.com> Date: Tue, 12 Jul 2016 15:43:29 +0800 MIME-Version: 1.0 In-Reply-To: <20160711144847.16651-1-marcandre.lureau@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] tap: use an exit notifier to call down_script List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: marcandre.lureau@redhat.com, qemu-devel@nongnu.org Cc: pbonzini@redhat.com, akong@redhat.com On 2016=E5=B9=B407=E6=9C=8811=E6=97=A5 22:48, marcandre.lureau@redhat.com= wrote: > From: Marc-Andr=C3=A9 Lureau > > We would like to move back net_cleanup() at the end of main function, > like it used to be until f30dbae63a46f23116715dff8d130c, but minimum > tap cleanup is necessary regarless at exit() time. Use an exit notifier > to call TAP down_script. If net_cleanup() is called first, then remove > the exit notifier as it will become a dangling pointer otherwise. > > Signed-off-by: Marc-Andr=C3=A9 Lureau > Suggested-by: Paolo Bonzini This looks like a tap specific solution. But at least slirp wants to do=20 some cleanup too. We need a generic solution. Does it work if we use=20 atexit(net_chr_cleanup) and first cleanup net and then chr at that functi= on? > --- > net/tap.c | 27 ++++++++++++++++++++------- > 1 file changed, 20 insertions(+), 7 deletions(-) > > diff --git a/net/tap.c b/net/tap.c > index 676bad4..e9c32f3 100644 > --- a/net/tap.c > +++ b/net/tap.c > @@ -58,6 +58,7 @@ typedef struct TAPState { > bool enabled; > VHostNetState *vhost_net; > unsigned host_vnet_hdr_len; > + Notifier exit; > } TAPState; > =20 > static void launch_script(const char *setup_script, const char *ifnam= e, > @@ -292,10 +293,22 @@ static void tap_set_offload(NetClientState *nc, i= nt csum, int tso4, > tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); > } > =20 > +static void tap_exit_notify(Notifier *notifier, void *data) > +{ > + TAPState *s =3D container_of(notifier, TAPState, exit); > + Error *err =3D NULL; > + > + if (s->down_script[0]) { > + launch_script(s->down_script, s->down_script_arg, s->fd, &err)= ; > + if (err) { > + error_report_err(err); > + } > + } > +} > + > static void tap_cleanup(NetClientState *nc) > { > TAPState *s =3D DO_UPCAST(TAPState, nc, nc); > - Error *err =3D NULL; > =20 > if (s->vhost_net) { > vhost_net_cleanup(s->vhost_net); > @@ -304,12 +317,8 @@ static void tap_cleanup(NetClientState *nc) > =20 > qemu_purge_queued_packets(nc); > =20 > - if (s->down_script[0]) { > - launch_script(s->down_script, s->down_script_arg, s->fd, &err)= ; > - if (err) { > - error_report_err(err); > - } > - } > + tap_exit_notify(&s->exit, NULL); > + qemu_remove_exit_notifier(&s->exit); > =20 > tap_read_poll(s, false); > tap_write_poll(s, false); > @@ -379,6 +388,10 @@ static TAPState *net_tap_fd_init(NetClientState *p= eer, > } > tap_read_poll(s, true); > s->vhost_net =3D NULL; > + > + s->exit.notify =3D tap_exit_notify; > + qemu_add_exit_notifier(&s->exit); > + > return s; > } > =20