From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753114AbeDSSKh (ORCPT ); Thu, 19 Apr 2018 14:10:37 -0400 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:39447 "EHLO out3-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751184AbeDSSKf (ORCPT ); Thu, 19 Apr 2018 14:10:35 -0400 X-ME-Sender: Subject: Re: [Xen-devel] [PATCH] xen-netfront: Fix hang on device removal To: netdev@vger.kernel.org Cc: Jason Andryuk , xen-devel@lists.xenproject.org, Eduardo Otubo , Juergen Gross , Boris Ostrovsky , open list References: <20180228122323.3914-1-jandryuk@gmail.com> From: Simon Gaiser Message-ID: <1b07e839-5633-3b1e-1997-b86a891b2962@invisiblethingslab.com> Date: Thu, 19 Apr 2018 18:10:00 +0000 MIME-Version: 1.0 In-Reply-To: <20180228122323.3914-1-jandryuk@gmail.com> Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="myGTiVextl6vFeRqaSm5HcOSlnXDVaIsW" 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) --myGTiVextl6vFeRqaSm5HcOSlnXDVaIsW Content-Type: multipart/mixed; boundary="gwO90y9nkFM5w1gygVmy6KSInYvYfczEg"; protected-headers="v1" From: Simon Gaiser To: netdev@vger.kernel.org Cc: Jason Andryuk , xen-devel@lists.xenproject.org, Eduardo Otubo , Juergen Gross , Boris Ostrovsky , open list Message-ID: <1b07e839-5633-3b1e-1997-b86a891b2962@invisiblethingslab.com> Subject: Re: [Xen-devel] [PATCH] xen-netfront: Fix hang on device removal References: <20180228122323.3914-1-jandryuk@gmail.com> In-Reply-To: <20180228122323.3914-1-jandryuk@gmail.com> --gwO90y9nkFM5w1gygVmy6KSInYvYfczEg Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable 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, an= d > xennet_remove would hang indefinitely. This hang prevents system > shutdown. >=20 > xennet_remove must be able to handle XenbusStateUnknown, and > netback_changed must also wake up the wake_queue for that state as well= =2E >=20 > Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading modul= e") I think this should go into stable since AFAIK the hanging network device can only be fixed by rebooting the guest. AFAICS this affects all 4.* branches since 5b5971df3bc2 got backported to them. Upstream commit c2d2e6738a209f0f9dffa2dc8e7292fc45360d61. Simon --gwO90y9nkFM5w1gygVmy6KSInYvYfczEg-- --myGTiVextl6vFeRqaSm5HcOSlnXDVaIsW Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEE3E8ezGzG3N1CTQ//kO9xfO/xly8FAlrY27MACgkQkO9xfO/x ly+uSxAAyh4Burc07vRFEo20sKnzrVL5x7BqgQAznYOWKsB5D6Yb1VaG11GTZfBp G5FiaorTVm9zdqmIddxBgBZINtn2/SWvr5LwJfeYBjebBtccu+91CyeDT0P0T56l FVut4ON195ZLYfH8eXE8y9Nvqh8M50n9dmeINrrelYzLbrkP6h9TSJ1h1tz4Jing o+kBnjQJ9wGAuAQyWv2053ta/3oCYOI4DZsFcFhDZcCuEz6Kll4a/WeSA8QcLp9y m3iTqIAxtbom+DHfWaZnRD9GO4nxflDJb9Xt34TxJn3RKn34XZ+NSVUPkz2l44oS k6OowweN7/faH1SuVl2UTfcMflBNjISzQddXfHUpdfk9nNMSe9k3jnrRkWGfBmvA FbiBhmUXcEAVYRDdiOgKMtnKboY1lWKaNE1CdoVdMBo32FgJc1eKWOwV6LiQ1Xpo gNfjfZqmvJ8ok9Px4sg12wlSXkchtocRup48FTPHvdqdUAQXDwPM7iS1KGLKQ+QA 8OayJEV19dyLQDRPy2kqynxJzt/0qX0hp/bNWG4MPawWJmSi2h5Mt2UrFsKqXEXa 1DzGw0pmN2NaN8mdhcW1NEe098qh9qipIiEGHqN9qkYkt2wtYZF6+p/Vf6zX7lb7 7vVbIvctoeGDpN9Q8eZYTUTwuDHAZcVZed2Dikrj+nk37pDxYqo= =a9YR -----END PGP SIGNATURE----- --myGTiVextl6vFeRqaSm5HcOSlnXDVaIsW--