From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65BBDC3DA7D for ; Mon, 19 Dec 2022 15:42:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232384AbiLSPmm (ORCPT ); Mon, 19 Dec 2022 10:42:42 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58090 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232359AbiLSPmg (ORCPT ); Mon, 19 Dec 2022 10:42:36 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC0DD120B6; Mon, 19 Dec 2022 07:42:35 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5927E6101A; Mon, 19 Dec 2022 15:42:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 444B1C433D2; Mon, 19 Dec 2022 15:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1671464554; bh=oiRflUUrN9bOaDwDQpqkHsr1lb3UHJCMBAT9e34G5mE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r5cDx+BtP2K4XWscbCzfdt8AoZagaehZj070cUl5VgcIS1p/YAUbp3ROeQZ192BKX q5AWMzNd7sErqwBkcyVIpBNAjtJrfc6dHqCmORCf8hxBGP6yYMXTxNuk0/ZMYeeqts mjX0w/5SGEE5rWy4bwI/UfZiC+zYiUW+YWBRPBT0= Date: Mon, 19 Dec 2022 16:42:32 +0100 From: Greg Kroah-Hartman To: Pratyush Yadav Cc: stable@vger.kernel.org, Wei Liu , Paul Durrant , "David S. Miller" , Marek =?iso-8859-1?Q?Marczykowski-G=F3recki?= , Jakub Kicinski , Sasha Levin , Puranjay Mohan , Maximilian Heyne , Julien Grall , xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5.4] xen-netback: move removal of "hotplug-status" to the right place Message-ID: References: <20221219153710.23782-1-ptyadav@amazon.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221219153710.23782-1-ptyadav@amazon.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 19, 2022 at 04:37:10PM +0100, Pratyush Yadav wrote: > The removal of "hotplug-status" has moved around a bit. First it was > moved from netback_remove() to hotplug_status_changed() in upstream > commit 1f2565780e9b ("xen-netback: remove 'hotplug-status' once it has > served its purpose"). Then the change was reverted in upstream commit > 0f4558ae9187 ("Revert "xen-netback: remove 'hotplug-status' once it has > served its purpose""), but it moved the removal to backend_disconnect(). > Then the upstream commit c55f34b6aec2 ("xen-netback: only remove > 'hotplug-status' when the vif is actually destroyed") moved it finally > back to netback_remove(). The thing to note being it is removed > unconditionally this time around. > > The story on v5.4.y adds to this confusion. Commit 60e4e3198ce8 ("Revert > "xen-netback: remove 'hotplug-status' once it has served its purpose"") > is backported to v5.4.y but the original commit that it tries to revert > was never present on 5.4. So the backport incorrectly ends up just > adding another xenbus_rm() of "hotplug-status" in backend_disconnect(). > > Now in v5.4.y it is removed in both backend_disconnect() and > netback_remove(). But it should only be removed in netback_remove(), as > the upstream version does. > > Removing "hotplug-status" in backend_disconnect() causes problems when > the frontend unilaterally disconnects, as explained in > c55f34b6aec2 ("xen-netback: only remove 'hotplug-status' when the vif is > actually destroyed"). > > Remove "hotplug-status" in the same place as it is done on the upstream > version to ensure unilateral re-connection of frontend continues to > work. > > Fixes: 60e4e3198ce8 ("Revert "xen-netback: remove 'hotplug-status' once it has served its purpose"") > Signed-off-by: Pratyush Yadav > --- > drivers/net/xen-netback/xenbus.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) Now queued up, thanks. greg k-h