From patchwork Mon Mar 14 11:34:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 551812 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 25031C433EF for ; Mon, 14 Mar 2022 11:34:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238933AbiCNLgD (ORCPT ); Mon, 14 Mar 2022 07:36:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239054AbiCNLgB (ORCPT ); Mon, 14 Mar 2022 07:36:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 625C64248E; Mon, 14 Mar 2022 04:34:51 -0700 (PDT) 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 8CF8561142; Mon, 14 Mar 2022 11:34:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 98C8BC340E9; Mon, 14 Mar 2022 11:34:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1647257690; bh=Ulz2gD+h9I+lhii4moSixTK+YMoNJueQAZjdiler7Qo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zxoyFH6lWHLMgPmJfN5/zT7bDotTl7nLYPiT5ZjXZxu+JZe+zrVCf0JCi959upleY 7NtsdPtLg7hGgOf+11jcRQ5bcOGE7Xi5HDxxKB+8QYgSgQ19COrYdiGHD/W93/SLx1 VueRsazEGHQzjF7L03gwF/SMQa3DvM024Wcuz1I8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= , Paul Durrant , Michael Brown , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.9 11/20] Revert "xen-netback: Check for hotplug-status existence before watching" Date: Mon, 14 Mar 2022 12:34:12 +0100 Message-Id: <20220314112730.834019108@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220314112730.388955049@linuxfoundation.org> References: <20220314112730.388955049@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Marek Marczykowski-Górecki [ Upstream commit e8240addd0a3919e0fd7436416afe9aa6429c484 ] This reverts commit 2afeec08ab5c86ae21952151f726bfe184f6b23d. The reasoning in the commit was wrong - the code expected to setup the watch even if 'hotplug-status' didn't exist. In fact, it relied on the watch being fired the first time - to check if maybe 'hotplug-status' is already set to 'connected'. Not registering a watch for non-existing path (which is the case if hotplug script hasn't been executed yet), made the backend not waiting for the hotplug script to execute. This in turns, made the netfront think the interface is fully operational, while in fact it was not (the vif interface on xen-netback side might not be configured yet). This was a workaround for 'hotplug-status' erroneously being removed. But since that is reverted now, the workaround is not necessary either. More discussion at https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Paul Durrant Reviewed-by: Michael Brown Link: https://lore.kernel.org/r/20220222001817.2264967-2-marmarek@invisiblethingslab.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/xen-netback/xenbus.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index e6646c8a7bdb..78788402edd8 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -1040,15 +1040,11 @@ static void connect(struct backend_info *be) xenvif_carrier_on(be->vif); unregister_hotplug_status_watch(be); - if (xenbus_exists(XBT_NIL, dev->nodename, "hotplug-status")) { - err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, - NULL, hotplug_status_changed, - "%s/%s", dev->nodename, - "hotplug-status"); - if (err) - goto err; + err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch, NULL, + hotplug_status_changed, + "%s/%s", dev->nodename, "hotplug-status"); + if (!err) be->have_hotplug_status_watch = 1; - } netif_tx_wake_all_queues(be->vif->dev);