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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham 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 373BAC3F2D7 for ; Tue, 3 Mar 2020 11:09:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A61E20674 for ; Tue, 3 Mar 2020 11:09:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728777AbgCCLJW (ORCPT ); Tue, 3 Mar 2020 06:09:22 -0500 Received: from relay10.mail.gandi.net ([217.70.178.230]:35497 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728173AbgCCLJW (ORCPT ); Tue, 3 Mar 2020 06:09:22 -0500 Received: from nexussix.ar.arcelik (unknown [84.44.14.226]) (Authenticated sender: cengiz@kernel.wtf) by relay10.mail.gandi.net (Postfix) with ESMTPSA id DE573240020; Tue, 3 Mar 2020 11:07:41 +0000 (UTC) From: Cengiz Can To: kbusch@kernel.org Cc: Chaitanya.Kulkarni@wdc.com, axboe@kernel.dk, helgaas@kernel.org, jack@suse.cz, linux-block@vger.kernel.org, stable@vger.kernel.org, tristmd@gmail.com, Cengiz Can Subject: Re: [PATCH] blktrace: Protect q->blk_trace with RCU Date: Tue, 3 Mar 2020 14:07:32 +0300 Message-Id: <20200303110731.65552-1-cengiz@kernel.wtf> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200302220639.GA2393@dhcp-10-100-145-180.wdl.wdc.com> References: <20200302220639.GA2393@dhcp-10-100-145-180.wdl.wdc.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Added a reassignment into the NULL check block to fix the issue. Fixes: c780e86dd48 ("blktrace: Protect q->blk_trace with RCU") Signed-off-by: Cengiz Can --- kernel/trace/blktrace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c index 4560878f0bac..29ea88f10b87 100644 --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -1896,8 +1896,10 @@ static ssize_t sysfs_blk_trace_attr_store(struct device *dev, } ret = 0; - if (bt == NULL) + if (bt == NULL) { ret = blk_trace_setup_queue(q, bdev); + bt = q->blk_trace; + } if (ret == 0) { if (attr == &dev_attr_act_mask) -- 2.25.1