From patchwork Thu Oct 26 01:27:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steven Rostedt X-Patchwork-Id: 158348 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:d641:0:b0:403:3b70:6f57 with SMTP id cy1csp355682vqb; Wed, 25 Oct 2023 18:28:07 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFvkPruMAJ0hSc3LDp2/xkDovUDORtQ2rB7xWaP+NjMWt8cUo8pf/ySJzzTTnaSnwBw1hR3 X-Received: by 2002:a1f:a9c3:0:b0:4a8:4218:804b with SMTP id s186-20020a1fa9c3000000b004a84218804bmr15285234vke.12.1698283687368; Wed, 25 Oct 2023 18:28:07 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1698283687; cv=none; d=google.com; s=arc-20160816; b=hcgqlJVXuBxFnWz5GVbWsoEUxk6BiZREJnYB+oGODukcBvGmo0FLg+11DD9cwiXGl9 ac/majVxdOtJZL5JUK75hBbvchKGHXJukQe7NXGhrsKS/jOYKBAC7x3sc5vcDm7MkLXz n2wHbZ+0Z8aGKzEHZk2n+wc1x50MVUtqS63+Amxwj/VGKrHhS2EcbL/ulIPZUZpmxb9s SmDjSGHAYiNXbBOlPNRwGOipgTx+NBINMJaPSTnwiT4uGhT8tjR3aY6glTGECD4TF+7S JFeh1puFeG+DtUZD2QqUrdJeLss0DWMVO9bFBzd80OSevGO9F5Ax0WqUBXNq4R43lRIT V1QA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:mime-version:references:subject:cc:to:from:date :user-agent:message-id; bh=E+JLr14FGwQp4fxwptxCcjEwrt3myv8MamoDyhW6U1E=; fh=cY9HGbp9RiQ9xCYqjybSe1/cIiXVFs0Cn9z6ge1iyyY=; b=03m0BJ3eEMUmsOFBEdf3RbZo2i0IvRv6qqnOJYioEcPrFcCBOrg+5KmtY+EeGG+G0o hUHkj1VjllBo1r9xUTnAcie4SxuMjmBH5bq5Qkrxo/LIj2x6n4/JUr5PZOz20zmJRFEK sb8GaXOb6rGd1m7KEw/dy4Eqm64bXVfHN8Ew9nD0Odc+FbJCDfiMNjG/whqVKHsTOApQ 1w7xEe2F6Kf51qMK6dGYEfbeNUib6SCc+fObtpL1u0HT1DaOElvw6A0jZAY8eD+wrhM2 sxZvHdzEbflRI2RH2EuD0e5jjqRTkWJMkXc+iOrj8vfnwgwNgFkuQqSpHlOxm/pf+ykD fBDg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: from snail.vger.email (snail.vger.email. [2620:137:e000::3:7]) by mx.google.com with ESMTPS id h204-20020a816cd5000000b0058cd7815d28si13129105ywc.190.2023.10.25.18.28.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Oct 2023 18:28:07 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 as permitted sender) client-ip=2620:137:e000::3:7; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:7 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 snail.vger.email (Postfix) with ESMTP id 724CA81B8000; Wed, 25 Oct 2023 18:28:06 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at snail.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232946AbjJZB2A (ORCPT + 25 others); Wed, 25 Oct 2023 21:28:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232710AbjJZB15 (ORCPT ); Wed, 25 Oct 2023 21:27:57 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6FF71185 for ; Wed, 25 Oct 2023 18:27:55 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1C47AC43395; Thu, 26 Oct 2023 01:27:55 +0000 (UTC) Received: from rostedt by gandalf with local (Exim 4.96) (envelope-from ) id 1qvpAA-00CqU5-05; Wed, 25 Oct 2023 21:27:54 -0400 Message-ID: <20231026012753.831438923@goodmis.org> User-Agent: quilt/0.66 Date: Wed, 25 Oct 2023 21:27:37 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Andrew Morton Subject: [for-next][PATCH 3/4] eventfs: Fix WARN_ON() in create_file_dentry() References: <20231026012734.358814002@goodmis.org> MIME-Version: 1.0 X-Spam-Status: No, score=-4.0 required=5.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net 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 (snail.vger.email [0.0.0.0]); Wed, 25 Oct 2023 18:28:06 -0700 (PDT) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1780779515684751705 X-GMAIL-MSGID: 1780779515684751705 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). Link: https://lore.kernel.org/linux-trace-kernel/20231024123628.62b88755@gandalf.local.home Cc: Masami Hiramatsu Cc: Mark Rutland Fixes: 5790b1fb3d672 ("eventfs: Remove eventfs_file and just use eventfs_inode") Signed-off-by: Steven Rostedt (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);