From patchwork Tue Feb 22 00:18:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= X-Patchwork-Id: 12754385 X-Patchwork-Delegate: kuba@kernel.org 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 DE340C433EF for ; Tue, 22 Feb 2022 00:19:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237556AbiBVATa (ORCPT ); Mon, 21 Feb 2022 19:19:30 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237815AbiBVATL (ORCPT ); Mon, 21 Feb 2022 19:19:11 -0500 Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F1E4925E85; Mon, 21 Feb 2022 16:18:32 -0800 (PST) Received: from compute3.internal (compute3.nyi.internal [10.202.2.43]) by mailout.west.internal (Postfix) with ESMTP id EC12B32020A4; Mon, 21 Feb 2022 19:18:30 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute3.internal (MEProxy); Mon, 21 Feb 2022 19:18:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm2; bh=XmMT3EWtd+ciLfBzi+9TAwPbS18Eh5Hhy+YbNx2fX t0=; b=ClWyCP3Q0+m9yPFE7QpnuAWSp8luBTmJ3dLZy+53AyJh/Zew6r3VyamYI iIhemKxWThFxC9kjEGU4HTzWxms0kukrEJ21uNabiUgyw1CWTJB8I6V/Yajjg6aG gJi1YtMtbrm7sM9Erce+fv++TOxyyHvQDRqtgOQNB2w83NYj3DclV9DMyMOCCNsa 4yZATPgb5G4jVwJtkfCtvFQN8JEHz6vt+tTs7J7HHu4aWtEHEEHMcn3ZO+9kB5jW VrLEjdY0doKSnZi71hE3tknHK7T/mwblYjPTeOwZu4g4jwtWSHWbG6ogEAKC9u+4 UhNrMNXlgXOqMVRm3xFGpr2MkjzXA== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrkeejgddvtdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhggtghogfesthekredtredtjeenucfhrhhomhepofgrrhgv khcuofgrrhgtiiihkhhofihskhhiqdfikphrvggtkhhiuceomhgrrhhmrghrvghksehinh hvihhsihgslhgvthhhihhnghhslhgrsgdrtghomheqnecuggftrfgrthhtvghrnhepffdt uefffeduhfelueegvdetheejvdehteelfeetfeekgfekkefggedtgefhieejnecuffhomh grihhnpehkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgr mhepmhgrihhlfhhrohhmpehmrghrmhgrrhgvkhesihhnvhhishhisghlvghthhhinhhgsh hlrggsrdgtohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 21 Feb 2022 19:18:28 -0500 (EST) From: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= To: linux-kernel@vger.kernel.org Cc: =?utf-8?q?Marek_Marczykowski-G=C3=B3recki?= , stable@vger.kernel.org, Michael Brown , Wei Liu , Paul Durrant , "David S. Miller" , Jakub Kicinski , xen-devel@lists.xenproject.org (moderated list:XEN NETWORK BACKEND DRIVER), netdev@vger.kernel.org (open list:XEN NETWORK BACKEND DRIVER) Subject: [PATCH v2 2/2] Revert "xen-netback: Check for hotplug-status existence before watching" Date: Tue, 22 Feb 2022 01:18:17 +0100 Message-Id: <20220222001817.2264967-2-marmarek@invisiblethingslab.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220222001817.2264967-1-marmarek@invisiblethingslab.com> References: <20220222001817.2264967-1-marmarek@invisiblethingslab.com> MIME-Version: 1.0 Organization: Invisible Things Lab Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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 Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Paul Durrant Reviewed-by: Michael Brown --- I believe this is the same issue as discussed at https://lore.kernel.org/xen-devel/20220113111946.GA4133739@dingwall.me.uk/ Cc: James Dingwall --- 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 3fad58d22155..990360d75cb6 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -824,15 +824,11 @@ 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);