From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-874563-1516768758-2-15337014105172487096 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.25, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='com', MailFrom='org', XOriginatingCountry='US' X-Spam-charsets: plain='iso-8859-1' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1516768758; b=RHfMEvMUji7JBdITR8qgW5cbynRONsgiMI3Yfh+xpHQFEUm wbrilozC4aXWJXZiPrsqknu5lYhmIsBwhxp+7WIJXVIjVacEf1CTcnXOkA7UYQCy UyDKpvqHRO5eQL2mA0PIeGv85I/THv9E9M8pqmLvb85QKD4PDp5SEsVtmcIAPpjS ipERd+4v0mwNOAPevEmv0+7xX3GpKK5RpedWeZ7JpESw9bKoLlkdWYZXAQaoKjNW rxJJI0gpLgm+6XLfDSypn0PxGaJJan6T5giftD7nOtCIsackLmShY2/noOxOLteP DaKI9QvvZn/NhSOj3zViX04DL1WFgekWdXuD+Qg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :references:in-reply-to:content-type:content-transfer-encoding :mime-version:sender:list-id; s=arctest; t=1516768758; bh=ly6kx/ ECaTZSsx3z/DluiMzf55fRLwpJy9m1CWGEMMw=; b=L5XrjOkYh6ZtuUDKyNnrtn y0HL9f0O4XszEZFDHkha5/5j/j7qErTNiq60+bUyhGbueSz5JX68azkyXHEAPFrp IP409b5YB0hRQgVU+6DdO0vudxEKi4fALFcttLdIw4+64yPqt1o+hP5/gkZ+96Dj 4oysS4taPayr9Vl44hrlUGlopjD2A/YBAcullsjumEfVgP0jTWTyZiBSqostv43s m4EcdWB8h1A3MFrIq2qzFm1p3IUsm5m5adm9sn5NEwXcLS5C4Y8i9cmD9GqDAWSO KB6yRqyATCnJzKGgJdhn02y316PoI/e89joVLQ/YN6dOkavKtLFzrUP1Xc9Cza7A == ARC-Authentication-Results: i=1; mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=e9eFyS1k x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=selector1; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=microsoft.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=microsoft.com header.result=pass header_is_org_domain=yes Authentication-Results: mx5.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=e9eFyS1k x-bits=1024 x-keytype=rsa x-algorithm=sha256 x-selector=selector1; dmarc=pass (p=reject,has-list-id=yes,d=none) header.from=microsoft.com; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=microsoft.com header.result=pass header_is_org_domain=yes Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932326AbeAXER3 (ORCPT ); Tue, 23 Jan 2018 23:17:29 -0500 Received: from mail-sn1nam02on0108.outbound.protection.outlook.com ([104.47.36.108]:12096 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932374AbeAXERY (ORCPT ); Tue, 23 Jan 2018 23:17:24 -0500 From: Sasha Levin To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: Eduardo Otubo , "David S . Miller" , Sasha Levin Subject: [PATCH AUTOSEL for 4.9 23/55] xen-netfront: remove warning when unloading module Thread-Topic: [PATCH AUTOSEL for 4.9 23/55] xen-netfront: remove warning when unloading module Thread-Index: AQHTlMn+zQtgcTdFZ0GE1WYmebvUlw== Date: Wed, 24 Jan 2018 04:15:40 +0000 Message-ID: <20180124041521.32223-23-alexander.levin@microsoft.com> References: <20180124041521.32223-1-alexander.levin@microsoft.com> In-Reply-To: <20180124041521.32223-1-alexander.levin@microsoft.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [52.168.54.252] x-ms-publictraffictype: Email x-microsoft-exchange-diagnostics: 1;DM5PR2101MB0933;7:w72+ts3Q6jkk+INjWZPTW7zG/QLILdIJ99AfqE+PVLuS9JbNtcDTh9cEH9dnW8ccfwF+XjjY74TKYps5AJXd5dyJaKNR9gimtFltbYst6ERWDRj+2rqlklQw86GfrZNsYPg3n/EeIV9YCcvbYwisYevTONQTvX9S4OyNarWnph8Su9BI2tGX+AwbRmajgZoXcVX0wX+ol1tFpF4BhB7Llvp072m8cq6xeR/0QEbmDPZ6YagH2XB2qD3eRLwgncBg x-ms-office365-filtering-correlation-id: 136bde8c-a1ad-4af3-0e70-08d562e15df4 x-ms-office365-filtering-ht: Tenant x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:(7020095)(4652020)(5600026)(4604075)(3008032)(48565401081)(4534165)(4627221)(201703031133081)(201702281549075)(2017052603307)(7193020);SRVR:DM5PR2101MB0933; x-ms-traffictypediagnostic: DM5PR2101MB0933: x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(28532068793085)(89211679590171)(788757137089); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(61425038)(6040501)(2401047)(5005006)(8121501046)(10201501046)(93006095)(93001095)(3002001)(3231046)(2400081)(944501161)(6055026)(61426038)(61427038)(6041288)(20161123560045)(20161123558120)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123562045)(20161123564045)(6072148)(201708071742011);SRVR:DM5PR2101MB0933;BCL:0;PCL:0;RULEID:;SRVR:DM5PR2101MB0933; x-forefront-prvs: 056297E276 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(346002)(39860400002)(376002)(366004)(39380400002)(396003)(189003)(199004)(105586002)(305945005)(478600001)(110136005)(10290500003)(76176011)(54906003)(106356001)(25786009)(66066001)(10090500001)(14454004)(3846002)(6116002)(1076002)(6346003)(97736004)(6506007)(5250100002)(2501003)(72206003)(59450400001)(4326008)(36756003)(3280700002)(3660700001)(102836004)(2906002)(5660300001)(53936002)(107886003)(2900100001)(6436002)(6512007)(99286004)(8936002)(68736007)(7736002)(86612001)(81156014)(86362001)(2950100002)(26005)(81166006)(8676002)(22452003)(6486002)(316002)(6666003)(22906009)(217873001);DIR:OUT;SFP:1102;SCL:1;SRVR:DM5PR2101MB0933;H:DM5PR2101MB1032.namprd21.prod.outlook.com;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; authentication-results: spf=none (sender IP is ) smtp.mailfrom=Alexander.Levin@microsoft.com; x-microsoft-antispam-message-info: F+KQ+6lt7QlTeTE7IZjX4ZWSFwwfA6V8bfccFWUsuPndzJCMkI2OQklws1INTtlTraLigRNcgSp2ZyHxtio9Mw== spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: microsoft.com X-MS-Exchange-CrossTenant-Network-Message-Id: 136bde8c-a1ad-4af3-0e70-08d562e15df4 X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Jan 2018 04:15:40.8370 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 72f988bf-86f1-41af-91ab-2d7cd011db47 X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM5PR2101MB0933 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: From: Eduardo Otubo [ Upstream commit 5b5971df3bc2775107ddad164018a8a8db633b81 ] v2: * Replace busy wait with wait_event()/wake_up_all() * Cannot garantee that at the time xennet_remove is called, the xen_netback state will not be XenbusStateClosed, so added a condition for that * There's a small chance for the xen_netback state is XenbusStateUnknown by the time the xen_netfront switches to Closed, so added a condition for that. When unloading module xen_netfront from guest, dmesg would output warning messages like below: [ 105.236836] xen:grant_table: WARNING: g.e. 0x903 still in use! [ 105.236839] deferring g.e. 0x903 (pfn 0x35805) This problem relies on netfront and netback being out of sync. By the time netfront revokes the g.e.'s netback didn't have enough time to free all of them, hence displaying the warnings on dmesg. The trick here is to make netfront to wait until netback frees all the g.e.= 's and only then continue to cleanup for the module removal, and this is done = by manipulating both device states. Signed-off-by: Eduardo Otubo Acked-by: Juergen Gross Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/xen-netfront.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 8d498a997e25..1a9dadf7b3cc 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -86,6 +86,8 @@ struct netfront_cb { /* IRQ name is queue name with "-tx" or "-rx" appended */ #define IRQ_NAME_SIZE (QUEUE_NAME_SIZE + 3) =20 +static DECLARE_WAIT_QUEUE_HEAD(module_unload_q); + struct netfront_stats { u64 packets; u64 bytes; @@ -2051,10 +2053,12 @@ static void netback_changed(struct xenbus_device *d= ev, break; =20 case XenbusStateClosed: + wake_up_all(&module_unload_q); if (dev->state =3D=3D XenbusStateClosed) break; /* Missed the backend's CLOSING state -- fallthrough */ case XenbusStateClosing: + wake_up_all(&module_unload_q); xenbus_frontend_closed(dev); break; } @@ -2160,6 +2164,20 @@ static int xennet_remove(struct xenbus_device *dev) =20 dev_dbg(&dev->dev, "%s\n", dev->nodename); =20 + if (xenbus_read_driver_state(dev->otherend) !=3D XenbusStateClosed) { + xenbus_switch_state(dev, XenbusStateClosing); + wait_event(module_unload_q, + xenbus_read_driver_state(dev->otherend) =3D=3D + XenbusStateClosing); + + xenbus_switch_state(dev, XenbusStateClosed); + wait_event(module_unload_q, + xenbus_read_driver_state(dev->otherend) =3D=3D + XenbusStateClosed || + xenbus_read_driver_state(dev->otherend) =3D=3D + XenbusStateUnknown); + } + xennet_disconnect_backend(info); =20 unregister_netdev(info->netdev); --=20 2.11.0