From patchwork Tue Oct 24 16:36:28 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 157638 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:ce89:0:b0:403:3b70:6f57 with SMTP id p9csp2067296vqx; Tue, 24 Oct 2023 09:36:52 -0700 (PDT) X-Google-Smtp-Source: AGHT+IF4/SfqHWuKo7WKYHqfhv4vZIoDTeiJCK8JRqgwzYM07mZLKXEKC0HERN2CYYL+uDdMqGuu X-Received: by 2002:a05:6a21:6d8a:b0:17d:53aa:d54d with SMTP id wl10-20020a056a216d8a00b0017d53aad54dmr3294898pzb.37.1698165412056; Tue, 24 Oct 2023 09:36:52 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1698165412; cv=none; d=google.com; s=arc-20160816; b=UbEG8oxK7wVE59Qno5NR4Dae/31SO1EV5hDU09b7jR3adPtwq9J0TUmou0XxADY0Ya 4TAiP3IpPf4IH28XXFUxr4/LxijMYIjOGXSf9s2yR3R0wRCVirK9XlXRdJGw8+ytWBPv GEG9sj3XMlpyYFXqwS9NLWxPO+xsuF96Y/BXbCH4EJXYnLq91/f7tjjQV7YcctVoQSJ/ FKZG+YkvyWcxJjJyizw2qQMUb/BU/CALokMAFDToBztvXx6n9iiHvQpggGF/Hg53Qjv1 XHB8kaulR6gviQNcLc3oHeg5R3tVU3eFPXtJkek1vMzrZYMr8fqoco8ymDBTxd7WsBjC Wbkg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :message-id:subject:cc:to:from:date; bh=/9lddvf25u62QkgaR3ThBa0z7l4dLEPtwCIvdxt93X8=; fh=GwUA7iixakkO5NTXBBRh1SUU4bI3bHSxo/Z9KQ16JZ0=; b=Jv+5sQbwailw+bX+jCyHU1YldOhLnCEHoYYlMENYa0Olg9j05aAwFJ5oNwU1JpDkGS 4CF9mBvp23ZaDLMlCa0xMJ0GQI57Ik4KeyvX0FGUefwe7RBgQ7IDo8/ToTICrdWxtO+X sN8qqYafetCQuCrMDme/7RUrlvejSQ7au17Fmot4xFFybAdWm53I9bPobLCJyyJhTZEm WIEmzzX6ufMt/+y3CoqDLuyek+Mir9BC2Btafye9rvZCgKwBe2mW/9FXQrUSCu8aay/l WT6EcviT+592OTu5wvpWNkaSaU+iVjxYPuwmwnuUkhvzT4lMWjszOVRXj2DmYNEHBxgd QRww== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from howler.vger.email (howler.vger.email. [23.128.96.34]) by mx.google.com with ESMTPS id m13-20020a17090a34cd00b002774cdc919csi10694060pjf.176.2023.10.24.09.36.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Oct 2023 09:36:52 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) client-ip=23.128.96.34; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.34 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by howler.vger.email (Postfix) with ESMTP id 1DC6C804399D; Tue, 24 Oct 2023 09:36:48 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at howler.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234798AbjJXQgg (ORCPT + 27 others); Tue, 24 Oct 2023 12:36:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234835AbjJXQgd (ORCPT ); Tue, 24 Oct 2023 12:36:33 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 699D5133 for ; Tue, 24 Oct 2023 09:36:31 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BE2AC433C9; Tue, 24 Oct 2023 16:36:30 +0000 (UTC) Date: Tue, 24 Oct 2023 12:36:28 -0400 From: Steven Rostedt To: LKML , Linux Trace Kernel Cc: Masami Hiramatsu , Mark Rutland Subject: [PATCH] eventfs: Fix WARN_ON() in create_file_dentry() Message-ID: <20231024123628.62b88755@gandalf.local.home> X-Mailer: Claws Mail 3.19.1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on howler.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (howler.vger.email [0.0.0.0]); Tue, 24 Oct 2023 09:36:48 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1780655494986614915 X-GMAIL-MSGID: 1780655494986614915 From: "Steven Rostedt (Google)" As the comment right above a WARN_ON() in create_file_dentry() states: * Note, with the mutex held, the e_dentry cannot have content * and the ei->is_freed be true at the same time. But the WARN_ON() only has: WARN_ON_ONCE(ei->is_free); Where to match the comment (and what it should actually do) is: dentry = *e_dentry; WARN_ON_ONCE(dentry && ei->is_free) Also in that case, set dentry to NULL (although it should never happen). Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Signed-off-by: Steven Rostedt (Google) Reviewed-by: Masami Hiramatsu (Google) --- fs/tracefs/event_inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c index 09ab93357957..4d2da7480e5f 100644 --- a/fs/tracefs/event_inode.c +++ b/fs/tracefs/event_inode.c @@ -264,8 +264,9 @@ create_file_dentry(struct eventfs_inode *ei, struct dentry **e_dentry, * Note, with the mutex held, the e_dentry cannot have content * and the ei->is_freed be true at the same time. */ - WARN_ON_ONCE(ei->is_freed); dentry = *e_dentry; + if (WARN_ON_ONCE(dentry && ei->is_freed)) + dentry = NULL; /* The lookup does not need to up the dentry refcount */ if (dentry && !lookup) dget(dentry);