From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759449Ab3GaLwr (ORCPT ); Wed, 31 Jul 2013 07:52:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:11151 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751098Ab3GaLwq (ORCPT ); Wed, 31 Jul 2013 07:52:46 -0400 Date: Wed, 31 Jul 2013 13:47:22 +0200 From: Oleg Nesterov To: Steven Rostedt Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Frederic Weisbecker , Andrew Morton , Masami Hiramatsu Subject: Re: [for-next-3.11][PATCH 0/8] ftrace/tracing: Event file fixes and ftrace function hash fixes Message-ID: <20130731114722.GA4416@redhat.com> References: <20130730112718.273490378@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130730112718.273490378@goodmis.org> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/30, Steven Rostedt wrote: > > Using the i_private and event_mutex > to verify that the event still exists to solve the race. To remind, we also need the "debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)" patch, otherwise we still have the problems with the opened files. Just in case, we need this fix even if .open() does trace_array_get() or tracing_open_generic_file() (removed by recent changes), rmdir can be called before we increment the counter and the deleted dentry breaks debugfs_remove_recursive(). But after the recent changes this fix becomes more important. An opened file confuses debugfs_remove_recursive() and after that you can't create another probe. Oleg.