From patchwork Thu Apr 6 18:10:46 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 9668021 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C7A71602B3 for ; Thu, 6 Apr 2017 18:11:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EA8D1285B7 for ; Thu, 6 Apr 2017 18:11:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DF0DC285BC; Thu, 6 Apr 2017 18:11:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3F588285B7 for ; Thu, 6 Apr 2017 18:11:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754124AbdDFSLG (ORCPT ); Thu, 6 Apr 2017 14:11:06 -0400 Received: from esa6.hgst.iphmx.com ([216.71.154.45]:8870 "EHLO esa6.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752478AbdDFSLC (ORCPT ); Thu, 6 Apr 2017 14:11:02 -0400 X-IronPort-AV: E=Sophos;i="5.37,160,1488816000"; d="scan'208";a="9115765" Received: from mail-co1nam03lp0021.outbound.protection.outlook.com (HELO NAM03-CO1-obe.outbound.protection.outlook.com) ([216.32.181.21]) by ob1.hgst.iphmx.com with ESMTP; 07 Apr 2017 02:11:02 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sharedspace.onmicrosoft.com; s=selector1-sharedspace-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version; bh=vQrCPqePYthpMLZ1Sh2APnNCZPEkZYcvc05zJgG9uOo=; b=fysfC7ztLjiC4cIA/yECO4jqZgxLJV3+C/uyRxdpbQAXTBba93b4GHwAg04l+w7HwEGc/7K0ebMuhZS+40IFcrOQphsD1RcU1Ob8VWGtTHOngsW0FehOIxuFW2X7wM9w6ivdJMSQdevwl0WVrPvYdWx6oLBvb/04vK/dgm+0rXE= Received: from MWHPR04CA0027.namprd04.prod.outlook.com (10.172.163.13) by BLUPR04MB103.namprd04.prod.outlook.com (10.255.213.149) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1005.10; Thu, 6 Apr 2017 18:10:58 +0000 Received: from SN1NAM04FT025.eop-NAM04.prod.protection.outlook.com (2a01:111:f400:7e4c::201) by MWHPR04CA0027.outlook.office365.com (2603:10b6:300:ee::13) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1019.17 via Frontend Transport; Thu, 6 Apr 2017 18:10:58 +0000 Authentication-Results: spf=pass (sender IP is 63.163.107.21) smtp.mailfrom=sandisk.com; kernel.dk; dkim=none (message not signed) header.d=none;kernel.dk; dmarc=bestguesspass action=none header.from=sandisk.com; Received-SPF: Pass (protection.outlook.com: domain of sandisk.com designates 63.163.107.21 as permitted sender) receiver=protection.outlook.com; client-ip=63.163.107.21; helo=milsmgep15.sandisk.com; Received: from milsmgep15.sandisk.com (63.163.107.21) by SN1NAM04FT025.mail.protection.outlook.com (10.152.88.103) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id 15.1.1019.14 via Frontend Transport; Thu, 6 Apr 2017 18:10:58 +0000 Received: from MILHUBIP04.sdcorp.global.sandisk.com (Unknown_Domain [10.201.67.162]) (using TLS with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by (Symantec Messaging Gateway) with SMTP id 6B.A6.29323.1B486E85; Thu, 6 Apr 2017 11:10:57 -0700 (PDT) Received: from milsmgip12.sandisk.com (10.177.8.100) by MILHUBIP04.sdcorp.global.sandisk.com (10.177.9.97) with Microsoft SMTP Server id 14.3.319.2; Thu, 6 Apr 2017 11:10:54 -0700 X-AuditID: 0ac94369-548749800000728b-eb-58e684b1ab46 Received: from exp-402881.sdcorp.global.sandisk.com ( [10.177.9.6]) by (Symantec Messaging Gateway) with SMTP id 37.8A.18148.DA486E85; Thu, 6 Apr 2017 11:10:53 -0700 (PDT) From: Bart Van Assche To: Jens Axboe CC: , Bart Van Assche , Christoph Hellwig , Hannes Reinecke Subject: [PATCH v3 1/5] blk-mq: Make it safe to use RCU to iterate over blk_mq_tag_set.tag_list Date: Thu, 6 Apr 2017 11:10:46 -0700 Message-ID: <20170406181050.12137-2-bart.vanassche@sandisk.com> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170406181050.12137-1-bart.vanassche@sandisk.com> References: <20170406181050.12137-1-bart.vanassche@sandisk.com> X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrELMWRmVeSWpSXmKPExsXCddJ5ke7GlmcRBl2PFS1W3+1ns1jwZi+b xcrVR5ks9t7SdmDxuHy21GP3zQY2j/VbrrJ4fN4kF8ASxWWTkpqTWZZapG+XwJWxbnoPU8Ev 7oo9H+4wNzC2cXUxcnJICJhIXPo0j6mLkYtDSGApk8SeM63MIAkhge2MEjdeicAUnV52jw2i aCOjxJefz1hAEmwCRhLf3s8Es0UEFCR6fq8EK2IWmMIoce7+FnaQhLBAvETj8y9ARRwcLAIq EnM3a4CEeQXsJaYs/sgCsUBeYtGmGWA2p4CDxMOTh5lAyoWAan6vcYMoaWKVmP7PDKJVUOLk zCdg5cwCEhIHX7yAulld4uSS+UwTGIVmISmbhaRsASPTKkax3Myc4tz01AJDU73ixLyUzOJs veT83E2MkJDO3MF494n3IUYBDkYlHt4FT59ECLEmlhVX5h5ilOBgVhLhTat/FiHEm5JYWZVa lB9fVJqTWnyIUZqDRUmc95zM1AghgfTEktTs1NSC1CKYLBMHp1QD44TJwf/Xbrxop1hhf75M RbI07aXYk3w9o0sKS2vvuOWZJWkfrL27bG41u++8U1N+9GkrXHa/zDArxNzlXjXH4zfbJSuS hRp3ch3gb9Cs7ezcvq0xjGeJq47vbEfB785+91btyjpYuHCP8s8fvTsdXuZ1r3oYba0SIWXw t53NIYPRQKemI5RPiaU4I9FQi7moOBEA+clYY2UCAAA= X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrCJMWRmVeSWpSXmKPExsXCtZGTTXdty7MIg31rLS1W3+1nszj4s43R YsGbvWwWK1cfZbLYe0vbgdXj8tlSj903G9g8pq05z+SxfstVFo/Pm+QCWKO4bFJSczLLUov0 7RK4MtZN72Eq+MVdsefDHeYGxjauLkZODgkBE4nTy+6xdTFycQgJrGeUaJ40gQkkwSZgJPHt /UwWEFtEQEGi5/dKsCJmgSmMEktffGADSQgLxEs0Pv8CVsQioCqxbOdOsDivgL3EvVstTBAb 5CUWbZoBVsMp4CDx8ORhoDgH0DZ7id9r3CYwci9gZFjFKJabmVOcm55ZYGikV5yYl5JZnK2X nJ+7iRESDlE7GK9PND/EyMTBKdXAKHa1c5LJm4r94tbJskJXt+nG8+4I2jntRrF1/7RW5+7S mXX6X9Y1lWj08e6e0pUt/U9q8QmDyLeLju3f3MPW8lsnWGfhH2P13p2xG9fkXBRV4mO5myX3 5YyShdDX+e8XlrzZWLd88fslP62/rJvlcX79sdt9EdWxioXxuSdij+4SvmvweVZBvBJLcUai oRZzUXEiAJ5Vvzq3AQAA MIME-Version: 1.0 X-EOPAttributedMessage: 0 X-MS-Office365-Filtering-HT: Tenant X-Forefront-Antispam-Report: CIP:63.163.107.21; IPV:NLI; CTRY:US; EFV:NLI; SFV:NSPM; SFS:(10019020)(6009001)(39450400003)(39410400002)(39840400002)(39400400002)(39850400002)(2980300002)(438002)(199003)(189002)(9170700003)(77096006)(76176999)(110136004)(50986999)(356003)(106466001)(8936002)(48376002)(8676002)(50466002)(38730400002)(36756003)(5003940100001)(2906002)(33646002)(1076002)(50226002)(189998001)(4326008)(6916009)(47776003)(305945005)(2950100002)(53936002)(86362001)(5660300001)(6666003)(81166006)(54906002); DIR:OUT; SFP:1102; SCL:1; SRVR:BLUPR04MB103; H:milsmgep15.sandisk.com; FPR:; SPF:Pass; MLV:sfv; A:1; MX:1; LANG:en; X-Microsoft-Exchange-Diagnostics: 1; SN1NAM04FT025; 1: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 X-MS-Office365-Filtering-Correlation-Id: eca70d6c-b9da-47ac-fc07-08d47d1846bf X-Microsoft-Antispam: UriScan:; BCL:0; PCL:0; RULEID:(22001)(8251501002)(2017030254075)(201703131423075)(201703031133081)(201702281549075); SRVR:BLUPR04MB103; X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 3: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 X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 25:ONvHlVotaEECQGfeGItFzmVSlbafKKigNbGdU1T9cDGeH+gtx/hUi88WMynYiR3nKYVKIe1fvNKcSfZ9Ei9rtWqqP06fLHLbpk8zlyhebXt2R20MFJNilijzgm4Y1ihWFxVvqkyVQUN6ub5voP8M8a9qSZhcSfPNsXjumfjvthK4ZG8XmemqHbO61EpnTCpdLlhnGFP0xwPaufZeBa5YVBpDTYYkfs5ZiNeryeR69Qb09YlkzflIHFSzi/UbWEKk3xwK2aV9ByDuZkia3QaGnZdfhSY6Stl3BnlNhTki+vZkp9HthOMuA9FrvLuMbS1dkFFdGqgz4Hb6b5KPuzRcPdR1fXp43+tPXJRJFCPl8qegcPnxOoFbFLa2yXaQyVgDMS/2iBGrek4sseRbq0Lup3aCODpyu1Qb+4pDXH08LbABm8bwViNIcszJ4a+6YfvSlMZnapukd8Q4Qai5Xhppyw==; 31:5AiwUljkLbheP4iwi2yL+GJht4D1MuEmFwh6OKfAsxS68uJ+zZl0N+OjihCzAXP7EKXmhoIYTmyJha1VlEeT6U6ntfkAjvJQJ546V/tbsVUE1MvmTJQy1XSkz6vfGSP7+nsvhynuSOWQq52L2ls8LfCRmhk9BQGIftI4Ob+DvU4aMTEiP/ZDPJOcSntS3Xo3vihqw3kUXqXQat3DHx+67+HmawPMutgFyRNAYagFeS9CyZyP55iS4HG7iKBeGVqz WDCIPOUTBOUND: EOP-TRUE X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 20: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 X-Microsoft-Antispam-PRVS: X-Exchange-Antispam-Report-Test: UriScan:(42932892334569); X-Exchange-Antispam-Report-CFA-Test: BCL:0; PCL:0; RULEID:(6040450)(601004)(2401047)(5005006)(8121501046)(13016025)(13018025)(3002001)(10201501046)(93006095)(93004095)(6055026)(6041248)(20161123560025)(20161123564025)(20161123555025)(201703131423075)(201702281528075)(201703061421075)(20161123562025)(6072148); SRVR:BLUPR04MB103; BCL:0; PCL:0; RULEID:; SRVR:BLUPR04MB103; X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 4:S808Og+78OD+sdt2bs/tVbGoLmyRmV3VfDUCTGMpTi0ViR3AdFQBWVyL9YkZQDG4bzmMEbaiLZZ58l02Q2JFQgFMP+qwH2NQDJWIe2I2mcU8qxfpTeCpsEUbeRdxTyyU8xVeYzfvj40TDkycj3vPy5mr9S7FsyWX3PG72v3VIVWOPiwWdSBFOSLZUNgkPvZFhlIf/c40lhHHFj2gebtwsx5Z3zgh8kVq3tNy9MyOeqZ3MHnW9dChU+irp+zi+wuUboyAKOWCI/9K0olNoZd0WQm9lcQhlKGYqEKy9dXLf0VbpHUXnTnf6uuN2QboLXcSjLcJPnfiFN4espv2H4khIvw+k8gl/vXxWSHnGhDgZDExJ6XDKdZL0KvNdqwFNt/2mVkGBwCNKVpdku6WAfuf07HEbOa1NjRxaA+R1lx1xKopvJ19LBWcsyt9vlZpC2cWU4GI3HOkvxx4QYkbiDa1rbff2VBhEN+oD1a/NI5t/b94/qGVQT8WudX8b/1//h6pbHTnKicF8qojLBvmT5Pwmjm+AqrNQRtdlbZb+IUD4c+RHaGuOYDCXAyCT91+jHuYwbvaono1e5msBscmLlKvXXfpv43fViW7UOUgAO+vZ4pqo3iKILivMXfiKkT5gon1PII6mDbQ49xKNlh4A9EtwcFLi3pyCGOp5KSvxoaHg3i3gBIFYYezYlNU+0VHFY3ZGg7JNO6rH+zTpG6lBa9rm8pItpjOf6LkzJGPkJG1yS3FuoL/0ZuQdZZfgm69/kd5eprkMUxZnEOgC0l/z3W9CUIzqzPm/fckiQfDJlqNrXZ2qZUWfHXjaOWwhlcYAYm/ X-Forefront-PRVS: 02698DF457 X-Microsoft-Exchange-Diagnostics: =?us-ascii?Q?1; BLUPR04MB103; 23:BiGLt0DY0NRzwkpUgJvCeoSanZEKW/D8bTg45PDRQH?= =?us-ascii?Q?BQQABFYi3zHx5TJIekm41YxkuBGUkCkSmfrvq/8MxufdsW7cTKTra0E7S8+A?= =?us-ascii?Q?jvypZ+uHK6NLkzeOS2o4DgOnuhVtT8alwVs0qjVGLy/6mZs37uJTWpXusrdI?= =?us-ascii?Q?L7+l6ySv1nRUZAh77TgC8t+k1zsmgk7kQdYKtTiUtsmJpNc5wGr02w6454cB?= =?us-ascii?Q?0ZxVLCpRBEwld5mU4SFLR/qv4n2plU9N+izlBIYK/BmmOC5yVtqgZSGetaEN?= =?us-ascii?Q?DwY3FMcjSYIg5Rc65GhFcMt/CN/F5iEjG3NdpmtmRgNDCvMLkh2EcwC/IMW8?= =?us-ascii?Q?HS/PdK5FJXidvJ05qcu5pbKxVSbrw5rUpe/1CC+eDUuoUMWwG0BpYoaEleHI?= =?us-ascii?Q?7QyQ+m08CHT3Cy8sbNm8KP8qlA9GTpwjxldz4MXQG4bkX+1uxzoyjwSTNC6x?= =?us-ascii?Q?VDyL4DIH2+0UGFg9RsMNALAVms2yUJzQjutiPi51ZteDlSTXXD7mFvD2ap//?= =?us-ascii?Q?73XkLAK0OyiHVyVl22kihJ4crBvOtYzZCPjZg3k+4lBiaondX/Um7JH3RY3G?= =?us-ascii?Q?rjZOrKZB/oKfCJ/ESuY/jpAZWgv8N8AgQAw9Li1LDEPnUGyLLzde0fQqNWmi?= =?us-ascii?Q?W3BA+66+6pG8yBNLFSIcKPjICXxbu+DRzp5ZbodlTS3TCkFFRJXbgoBNUFFv?= =?us-ascii?Q?PTyBtkLpFEP6d5+EflyRHpxB9nhWUMLRCWYSMWbF3QieANOuB9jrgHPc9zyP?= =?us-ascii?Q?UJk0fKMdpQAkJ0q4dFGEpF4r1DqsDhq4kzFFpK8s9hULzkydRqi0Y1VbngV6?= =?us-ascii?Q?P8JI6CDczjTGMi3Xo+CItGhsZsf6Gr3aYte8UBlhhZ0CIFutwRAyaMY8+iAE?= =?us-ascii?Q?U9dRC4JY0WwpUhKZwmhQ34LUgmDwwzGjxi7h2gGkjJuV06yc7GnvpmN//RIc?= =?us-ascii?Q?IyKtUfvS7qNEZltehRR9fzK2TvVveoxLk+OkaV++tZoPx0rtPi/Ojlr+1vFe?= =?us-ascii?Q?eUVn74y3ozRFxIDK80B/2C?= X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 6:zJMM+gR6mRLwvXXjeQ30Ar79bg+GlOkZHQzm2Ycbw9H+zIXYA6bt7o0lRGo1P1xRlTJk0ig8tC5UCj1oEizAP4cPwfHF0eN+X+esTXackbSNCoKJnHQyHcC50nh8sKO7Bm/wyrI9iWgfTbf7TeUNAaq9ZRKa9k7yrTI/W3Z7Ai6K4Pu1zGjDhiIw2wS5b8btNpecLvxQF7I8+GfwuVQveetw2HeVY00LdCMUtmQlJPd8Urte9hz9ZNSVjeiPoHRxFuRIr38x2vSGtMCz1Mlf6sNTWn8mvPP1rGwDV0IM/MKkeQX6JlCjc1sXIsd6noigWa3jJdsYjCIEJDJ/Mwv8vySAgBguRQOc0YK/bO2LZwmsxYNDqRR0lfxZuAZMZKBqAEe8WCIdR6VFJx2arLQYoRjVpBO2T4YsI3wkVmL5knQ=; 5:77e/HydjyBhBmLj86hbGSCO5r8MjPAIPgPlWKQ7CzhMdAQ1/gIETgc/h793UC6A7Qvh6O0sF0mh5kwBzjsuVuY5s3Pda8wcti29FCLsG1MFROBp7Vg7HzbeWBzWea+OIizJPC4VvR/eXlBv+KUN+AQ==; 24:298nz6cPTVphOc7yftsBHa5gf2TSIJMVX7WXUaKivEr3Ja4Lgvc7Y4bzEY7HC9wUFUFF/hPsuPV8r9fqJI9Iw85MMr9NFN4EFzjMQ2vW8ko= SpamDiagnosticOutput: 1:99 SpamDiagnosticMetadata: NSPM X-Microsoft-Exchange-Diagnostics: 1; BLUPR04MB103; 7:Gwpbfx7a2LHJz70nROMGfL+fcf0gFIa7s1eoFapeYt5o3VB0t4y/GIdd3P21legOk/QdobKQSdHUwKn1W1v0Bvs8/zwiKXYCyWkOkraouysOvBvKCQT8pxlArytLTA70DsNzBrvuwxXpyW43chaUMoCQsXV5d0ZyclIQYqrpIPX5yRG5UiWvw1m2Sdta66wOroBTpP5gRMZCMXugYO/QHn8v6Lrkbd2VoVXQMTvkGJPgmzmMEk6JUbVIg68rKTJT7hbiBv85JnOYit3kyYvrEH/Z+3rxBSd7NumcfUHt8LnawzhsdvWN4siffVn7npRrjjyddUVBQf231tvUU/wzaA==; 20:c8l1ihm6qWEpT88Volo8T/w+0tchpXwXe1sg+C/syXhjNfMicfXRZdtPNX1FosyK4MHkERB/syM37FjrNlbjYhTZKC26+8GaT2/XV7CYCk7QsokQrpGgoNVV4OAllB+8gYFSWqDPwgnjk7jP40gqtC8U6CImFY9kiotp7aSDFaw= X-OriginatorOrg: sandisk.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Apr 2017 18:10:58.1694 (UTC) X-MS-Exchange-CrossTenant-Id: b61c8803-16f3-4c35-9b17-6f65f441df86 X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=b61c8803-16f3-4c35-9b17-6f65f441df86; Ip=[63.163.107.21]; Helo=[milsmgep15.sandisk.com] X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: BLUPR04MB103 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Since the next patch in this series will use RCU to iterate over tag_list, make this safe. Add lockdep_assert_held() statements in functions that iterate over tag_list to make clear that using list_for_each_entry() instead of list_for_each_entry_rcu() is fine in these functions. Signed-off-by: Bart Van Assche Cc: Christoph Hellwig Cc: Hannes Reinecke --- block/blk-mq.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/block/blk-mq.c b/block/blk-mq.c index f7cd3208bcdf..b5580b09b4a5 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2076,6 +2076,8 @@ static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared) { struct request_queue *q; + lockdep_assert_held(&set->tag_list_lock); + list_for_each_entry(q, &set->tag_list, tag_set_list) { blk_mq_freeze_queue(q); queue_set_hctx_shared(q, shared); @@ -2096,6 +2098,8 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q) blk_mq_update_tag_set_depth(set, false); } mutex_unlock(&set->tag_list_lock); + + synchronize_rcu(); } static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set, @@ -2601,6 +2605,8 @@ void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues) { struct request_queue *q; + lockdep_assert_held(&set->tag_list_lock); + if (nr_hw_queues > nr_cpu_ids) nr_hw_queues = nr_cpu_ids; if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)