Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751412Ab3GQCLI (ORCPT ); Tue, 16 Jul 2013 22:11:08 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:51300 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751186Ab3GQCLG (ORCPT ); Tue, 16 Jul 2013 22:11:06 -0400 Message-ID: <51E5FD33.4040604@hitachi.com> Date: Wed, 17 Jul 2013 11:10:59 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Oleg Nesterov Cc: Steven Rostedt , Peter Zijlstra , Frederic Weisbecker , linux-kernel@vger.kernel.org, Ingo Molnar , Arnaldo Carvalho de Melo , Andrew Morton , jovi.zhangwei@huawei.com, Jiri Olsa , Srikar Dronamraju Subject: Re: [RFC PATCH V2] tracing: Check f_dentry before accessing event_file/call in inode->i_private References: <20130705003223.GA4981@redhat.com> <20130709075519.2583.96462.stgit@mhiramat-M0-7522> <20130715181659.GA18505@redhat.com> In-Reply-To: <20130715181659.GA18505@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1259 Lines: 38 (2013/07/16 3:16), Oleg Nesterov wrote: > On 07/09, Masami Hiramatsu wrote: >> >> To avoid this, when opening events/*/*/enable, we have to ensure >> the dentry of the file is not unlinked yet, under event_mutex >> is locked. > > Probably this can work, but I am starting to think that this ref > count becomes toooooo complex.... Oleg, I agree that is a bit complex way to fix but it can fix. However, I think we should fix bugs first, because there are bugs. I don't like to leave a bug in the kernel as it is, while we re- start discussing new approach... > Could you please look at the draft patch I sent in another email? I'm happy to see the series, and I guess it will take a long discussion and review time again. So, I'd like to suggest you getting these fixes into ftrace as first-aid treatment, and discuss your new series. Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/