From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753366AbeDSUJ1 (ORCPT ); Thu, 19 Apr 2018 16:09:27 -0400 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:49417 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752153AbeDSUJ0 (ORCPT ); Thu, 19 Apr 2018 16:09:26 -0400 X-ME-Sender: Subject: Re: [Xen-devel] [PATCH] xen-netfront: Fix hang on device removal To: Jason Andryuk Cc: netdev@vger.kernel.org, xen-devel@lists.xenproject.org, Eduardo Otubo , Juergen Gross , Boris Ostrovsky , open list References: <20180228122323.3914-1-jandryuk@gmail.com> <1b07e839-5633-3b1e-1997-b86a891b2962@invisiblethingslab.com> From: Simon Gaiser Message-ID: <6ad676c8-476f-1181-1acd-985671f6c837@invisiblethingslab.com> Date: Thu, 19 Apr 2018 20:09:00 +0000 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="5u8trKVAeNy4LF1MR15s5bqCN9UIos27C" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --5u8trKVAeNy4LF1MR15s5bqCN9UIos27C Content-Type: multipart/mixed; boundary="jAv05fVE9GqNrG6iq4E36ns4Fw2mTx1hD"; protected-headers="v1" From: Simon Gaiser To: Jason Andryuk Cc: netdev@vger.kernel.org, xen-devel@lists.xenproject.org, Eduardo Otubo , Juergen Gross , Boris Ostrovsky , open list Message-ID: <6ad676c8-476f-1181-1acd-985671f6c837@invisiblethingslab.com> Subject: Re: [Xen-devel] [PATCH] xen-netfront: Fix hang on device removal References: <20180228122323.3914-1-jandryuk@gmail.com> <1b07e839-5633-3b1e-1997-b86a891b2962@invisiblethingslab.com> In-Reply-To: --jAv05fVE9GqNrG6iq4E36ns4Fw2mTx1hD Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Jason Andryuk: > On Thu, Apr 19, 2018 at 2:10 PM, Simon Gaiser > wrote: >> Jason Andryuk: >>> A toolstack may delete the vif frontend and backend xenstore entries >>> while xen-netfront is in the removal code path. In that case, the >>> checks for xenbus_read_driver_state would return XenbusStateUnknown, = and >>> xennet_remove would hang indefinitely. This hang prevents system >>> shutdown. >>> >>> xennet_remove must be able to handle XenbusStateUnknown, and >>> netback_changed must also wake up the wake_queue for that state as we= ll. >>> >>> Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading mod= ule") >> >> I think this should go into stable since AFAIK the hanging network >> device can only be fixed by rebooting the guest. AFAICS this affects a= ll >> 4.* branches since 5b5971df3bc2 got backported to them. >> >> Upstream commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61. >=20 > Simon, >=20 > Yes, I agree. I actually submitted the request to stable earlier > today, so hopefully it gets added soon. Ok, great. (I checked the stable patch queue, but didn't check the mailing list archive). > Have you experienced this hang? Yes, it's affecting the kernel shipped by Qubes OS (see [1]). Thanks, Simon. [1]: https://github.com/QubesOS/qubes-issues/issues/3657 --jAv05fVE9GqNrG6iq4E36ns4Fw2mTx1hD-- --5u8trKVAeNy4LF1MR15s5bqCN9UIos27C Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE3E8ezGzG3N1CTQ//kO9xfO/xly8FAlrY948ACgkQkO9xfO/x ly9FHg//QOF2+kbnv9PmuOMSIPxmcg80tWRRkhsa9ZEqrFY5EB1OcTYy1bNfPAS+ frypECcQSl6M2G9eyB+aLFMWnEkndKEAQowIS2iXzqQp/O1y8CoO2Rhnr8u45Ft4 zSRiR+Y2b4tOIqpkjwuUUN9kyVcMYgdpCX4uGrIWl4o7fvaEOd2rbfwVXcfkGANR TlwyED4FI1WgTq3rYl+WRC4lc1GvJMBl0lfwIGQFqnquj3yuOaLObDlJpEnJPRSz yH4VCNsevrupxvy0xNJkOzIQmHH/0aHCnXarSMC5b1xGQaODHCm+N+NophaeN7h3 jgD1F6qZKT7BANQnyNDq0J2W2jRVLxD7uFFo5x/kXWuwaDUFJ1+yvIpPALYzAWzR 9UnvvNKXmr4p1FFa3yeqBi2zn7Lm8AHpT9qsMH/5Uhas9PU3hmawsEk8wflS9jtX BZR34tmvVICAz/fFXJaN3+YK8HPrebcWz9TtAHCYNcD9vsc8B7A2fnVOxfWfrPc+ A1qZTC8HNtQB8KeNgwHMPQR/VHaq+fKFxcG9J4154KkAkmEkB5t2prjtT0Xo2tPo 8PZPVPz12K3eoeQU3ZwMkxle9k1dldN5R3d48fw5RpnLYY53arQhn+KzZR3wTEJx iuu3aqUZy45QD1HWHNIN/lBgGZKaYQniuTVKY797+gx8b7aJl3k= =Z+I/ -----END PGP SIGNATURE----- --5u8trKVAeNy4LF1MR15s5bqCN9UIos27C--