From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753034AbbKHRJk (ORCPT ); Sun, 8 Nov 2015 12:09:40 -0500 Received: from mail.kernel.org ([198.145.29.136]:34596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752726AbbKHRJf (ORCPT ); Sun, 8 Nov 2015 12:09:35 -0500 Message-Id: <20151108170931.657769168@goodmis.org> User-Agent: quilt/0.61-1 Date: Sun, 08 Nov 2015 12:09:08 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Jiaxing Wang Subject: [for-next][PATCH 1/2] tracing: Make tracing work when debugfs is not configured in References: <20151108170907.409729929@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0001-tracing-Make-tracing-work-when-debugfs-is-not-config.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jiaxing Wang Currently tracing_init_dentry() returns -ENODEV when debugfs is not configured in, which causes tracefs not populated with tracing files and directories, so we will get an empty directory even after we manually mount tracefs. We can make tracing_init_dentry() return NULL if debugfs is not configured in and can manually mount tracefs. But return -ENODEV if debugfs is configured in but not initialized or failed to create automount point as that would break backward compatibility with older tools. Link: http://lkml.kernel.org/r/1446797056-11683-1-git-send-email-hello.wjx@gmail.com Signed-off-by: Jiaxing Wang Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2198a630ef58..08af79c106e1 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6847,7 +6847,9 @@ struct dentry *tracing_init_dentry(void) if (tr->dir) return NULL; - if (WARN_ON(!debugfs_initialized())) + if (WARN_ON(!tracefs_initialized()) || + (IS_ENABLED(CONFIG_DEBUG_FS) && + WARN_ON(!debugfs_initialized()))) return ERR_PTR(-ENODEV); /* -- 2.6.1