From patchwork Mon Feb 21 03:42:13 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: 12753001 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 64182C433F5 for ; Mon, 21 Feb 2022 03:42:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344380AbiBUDnK (ORCPT ); Sun, 20 Feb 2022 22:43:10 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:44368 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344371AbiBUDnI (ORCPT ); Sun, 20 Feb 2022 22:43:08 -0500 Received: from wout3-smtp.messagingengine.com (wout3-smtp.messagingengine.com [64.147.123.19]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 742F33C70E; Sun, 20 Feb 2022 19:42:45 -0800 (PST) Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailout.west.internal (Postfix) with ESMTP id 412EC32001BB; Sun, 20 Feb 2022 22:42:44 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute5.internal (MEProxy); Sun, 20 Feb 2022 22:42:45 -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=kRJmWAWFjKOALsTRLgibyhb8NsyL7NusOB/YUc9eB kM=; b=hd0w/MJf6l//ha5NyaJHPHtK+xblj4CF7MnwjPQP918OiOgwP+vE+zlRl vkKsrgeohaO+ZE2PT3ab/v5Bc9Lk+yhUhBm09xahRA0oGJ3NTTz1cuqxoEotitz4 mjy7FKfgTgsNNgnWzt5bk4ujJFPRPZVdhbEFkj4iCTwJqJ5gnUoKQYC8/t0eQ70k HC6j3ozXuG1GM2BG5LH52Y0kkfPIfAxBZPdE/BASgP0MnByqcAXv7wfm+lR+/awr aBxwKvbMEafVx1ppp2sukMezYqZmd5zK3LuF8M4os1aelsbNjxNcbeUiW+UdLHLJ RmtUwsrOae1YyHt21nbhMq9AKRyNw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvvddrkeehgdeitdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpefhvffufffkofgjfhggtghogfesthekredtredtjeenucfhrhhomhepofgrrhgv khcuofgrrhgtiiihkhhofihskhhiqdfikphrvggtkhhiuceomhgrrhhmrghrvghksehinh hvihhsihgslhgvthhhihhnghhslhgrsgdrtghomheqnecuggftrfgrthhtvghrnhepffdt uefffeduhfelueegvdetheejvdehteelfeetfeekgfekkefggedtgefhieejnecuffhomh grihhnpehkvghrnhgvlhdrohhrghenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgr mhepmhgrihhlfhhrohhmpehmrghrmhgrrhgvkhesihhnvhhishhisghlvghthhhinhhgsh hlrggsrdgtohhm X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 20 Feb 2022 22:42:42 -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 2/2] Revert "xen-netback: Check for hotplug-status existence before watching" Date: Mon, 21 Feb 2022 04:42:13 +0100 Message-Id: <20220221034214.2237097-2-marmarek@invisiblethingslab.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220221034214.2237097-1-marmarek@invisiblethingslab.com> References: <20220221034214.2237097-1-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 --- 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 ce0f3035bee8..9d7a3a92959f 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);