From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 110AAC55189 for ; Wed, 22 Apr 2020 08:32:22 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CD75F206B9 for ; Wed, 22 Apr 2020 08:32:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ri4XZ1vU" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CD75F206B9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=0HlSG/C2JnAcX1yiQkAknGpYZpxOD81UpZwXntrw9gA=; b=ri4XZ1vUty3RAn 1ijNsdxDGFiK0SCO4+Jiz3oG+zPnkJkTEpATFVkBAW24RcRTHvhoh6gapubkpCetOxvzsxruAJPcS LBFY0YWHTMq4WYVHTdovG1jsjU6NsyPnirByvrs8xbnYjIGLJnrxO/1ovZyBA1Okw05tRLasz56tq Ad23/OzZfLBOrpDO85MDFxY7gltzv7/c+ZypP9jzrbRThbrUARFugsg06oA9HJhAKj2Dsfy7wsHDK kOcAYziOvaYAR6ZOsX5rSC5VuktesQO2MOKO4bZEzFfbtl6ZWDJLQPoRRy1ku056FZoQAlw2dmZkl B9ByKMIS6zfkcLAZNB8Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRAns-0006Kt-BL; Wed, 22 Apr 2020 08:32:20 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jRAnh-000680-Tj for linux-nvme@lists.infradead.org; Wed, 22 Apr 2020 08:32:11 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 1AF7368C7B; Wed, 22 Apr 2020 10:32:08 +0200 (CEST) Date: Wed, 22 Apr 2020 10:32:07 +0200 From: Christoph Hellwig To: Chaitanya Kulkarni Subject: Re: [PATCH 5/6] nvmet: centralize port enable access for configfs Message-ID: <20200422083207.GB25341@lst.de> References: <20200419235242.60355-1-chaitanya.kulkarni@wdc.com> <20200419235242.60355-6-chaitanya.kulkarni@wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200419235242.60355-6-chaitanya.kulkarni@wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200422_013210_112781_D3BCBC81 X-CRM114-Status: UNSURE ( 7.08 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sagi@grimberg.me, linux-nvme@lists.infradead.org, hch@lst.de Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org > +static bool nvmet_is_port_enabled(struct nvmet_port *p, const char *caller) > +{ > + bool enabled; > + > + /* > + * Right now port->enabled is accessed in follwoing two code paths > + * which are protected by the nvmet_config_sem :- > + * 1. nvmet_subsys allow/drop link() -> nvmet_port_enable/disable() > + * setting port->enabled true/false respectively. > + * 2. nvmet_referral_enable/disable() -> nvmet_port_enable/disable() > + * setting port->enabled true/false respectively. > + * Use read nvmet_config_sem when reading enable condition. > + */ > + down_read(&nvmet_config_sem); > + enabled = p->enabled; > + up_read(&nvmet_config_sem); Taking a lock around checking a single scalar value is rather pointless. _______________________________________________ linux-nvme mailing list linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme