From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-874563-1516768495-2-13249261220868312935 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=1516768495; b=PlRqq3+ooPgqusvyP0QdOyapDTXHRlpAKLiWJtIrbY/oqvw W2uJNYDKD2+rV5V+1AZ6+DKzJ/TtMZRFhyegzRSuZMXkl89uqOKREiIzzoxP+HH2 oWxLg3PuN2R7+SKm+va903TrRdNY+v6pZ4DOVV7WpskzpdCO5wiei0E328H7f591 uRhLjWipWPWsCBpXGlkYBhZP2MwupBGRDLLW5TvKBjTAliXkefbD+HbEWWiGhy6C fxUh2NEifsLQX8LQ6YxF0Za8t4ZwS987E1CeqSzzygmtbR81TSjzLtEK7arCjmol fkWhhCG1ntOOgSt/Hr3daRCW9UbVTwarBdcClhw== 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=1516768495; bh=zoURWl proBuTmptzUDbJ79m2l4ZsUZ3/wUTyQQo2vq8=; b=W2GINjMBrcjAS/a5oSQmbv QENoh8Voz/yCUPtvhdsycidB1HL7ks42i674G4/h31I+epCQeK9GmU/ivWUt4Hfn SAaHSOc01QO7Not8jYJdfnCh8//lZVxEbU5pejCYbmZNMcGpkEVXD9TKJXq984Ww fbFJuCJOwblwDDx2hTQb3Mjb1LILQOnziNBTzbgd2G1pi53xFbtSZBmapj+jOwhl 0LEpepRphYRzcp3tMnIxdFb40a6jGuvSmdw/OxyRrncc9h61FxjByJsXvD56zEyo DIz+uZmkkQiZf1hEHzxbGFQtui1ZOwfDmRqrnHb43dwP5nBssIy1Zm81kUsWZscw == ARC-Authentication-Results: i=1; mx4.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=gilNhSw1 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: mx4.messagingengine.com; arc=none (no signatures found); dkim=pass (1024-bit rsa key sha256) header.d=microsoft.com header.i=@microsoft.com header.b=gilNhSw1 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 S932256AbeAXESq (ORCPT ); Tue, 23 Jan 2018 23:18:46 -0500 Received: from mail-sn1nam02on0098.outbound.protection.outlook.com ([104.47.36.98]:53569 "EHLO NAM02-SN1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932174AbeAXESM (ORCPT ); Tue, 23 Jan 2018 23:18:12 -0500 From: Sasha Levin To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" CC: Jiang Biao , Al Viro , Minchan Kim , Michal Hocko , "zhong.weidong@zte.com.cn" , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH AUTOSEL for 4.9 38/55] fs/mbcache.c: make count_objects() more robust Thread-Topic: [PATCH AUTOSEL for 4.9 38/55] fs/mbcache.c: make count_objects() more robust Thread-Index: AQHTlMoDWy9eIm1/U0uOWqdalVUAcw== Date: Wed, 24 Jan 2018 04:15:49 +0000 Message-ID: <20180124041521.32223-38-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:ftMft9aFMdkmQoe/C3m8hTkw1LW3rrbAtSy5dfDwPxIGBJTyd/G/cCTgVqQPiusAqE1c6aWU1Ne7Qe4dHP67h/oXvJMLgU9WrcxiC7HHUCh+262Zzi5VFUmubyknPttSD1Ktvids6qa/pNKDVu5H5lujakTmC7V4OiAZLbtEISwDpSogdFqudwDJKwxYxH4Mww0EzL0PMjdjxfyQ2jrOHCAUufXN2XXHb2RvJokMVsZGb7xvktc27XmTuNejrMOb x-ms-office365-filtering-correlation-id: 3279daf1-0c13-4f8f-2052-08d562e178b3 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)(42068640409301); 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)(966005)(2501003)(72206003)(59450400001)(4326008)(36756003)(3280700002)(3660700001)(102836004)(2906002)(5660300001)(53936002)(107886003)(2900100001)(6436002)(6512007)(6306002)(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: fZNkfXDVnjcdiEfRRGnGokhW37ZoquCEqrKpP5cHaecx1AVIZeWHOrQj77iWJhJWHX1Qy6T/8Q0+OTmqNMKYtA== 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: 3279daf1-0c13-4f8f-2052-08d562e178b3 X-MS-Exchange-CrossTenant-originalarrivaltime: 24 Jan 2018 04:15:49.1419 (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: Jiang Biao [ Upstream commit d5dabd633922ac5ee5bcc67748f7defb8b211469 ] When running ltp stress test for 7*24 hours, vmscan occasionally emits the following warning continuously: mb_cache_scan+0x0/0x3f0 negative objects to delete nr=3D-9232265467809300450 ... Tracing shows the freeable(mb_cache_count returns) is -1, which causes the continuous accumulation and overflow of total_scan. This patch makes sure that mb_cache_count() cannot return a negative value, which makes the mbcache shrinker more robust. Link: http://lkml.kernel.org/r/1511753419-52328-1-git-send-email-jiang.biao= 2@zte.com.cn Signed-off-by: Jiang Biao Cc: Al Viro Cc: Minchan Kim Cc: Michal Hocko Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/mbcache.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/mbcache.c b/fs/mbcache.c index c5bd19ffa326..35ab4187bfe1 100644 --- a/fs/mbcache.c +++ b/fs/mbcache.c @@ -269,6 +269,9 @@ static unsigned long mb_cache_count(struct shrinker *sh= rink, struct mb_cache *cache =3D container_of(shrink, struct mb_cache, c_shrink); =20 + /* Unlikely, but not impossible */ + if (unlikely(cache->c_entry_count < 0)) + return 0; return cache->c_entry_count; } =20 --=20 2.11.0