From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 975C3C352A4 for ; Mon, 10 Feb 2020 19:23:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72A0220838 for ; Mon, 10 Feb 2020 19:23:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727433AbgBJTXN (ORCPT ); Mon, 10 Feb 2020 14:23:13 -0500 Received: from zeniv.linux.org.uk ([195.92.253.2]:35746 "EHLO ZenIV.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727003AbgBJTXN (ORCPT ); Mon, 10 Feb 2020 14:23:13 -0500 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j1Ee6-00AWd4-KS; Mon, 10 Feb 2020 19:23:02 +0000 Date: Mon, 10 Feb 2020 19:23:02 +0000 From: Al Viro To: Linus Torvalds Cc: Alexey Gladkov , LKML , Kernel Hardening , Linux API , Linux FS Devel , Linux Security Module , Akinobu Mita , Alexey Dobriyan , Andrew Morton , Andy Lutomirski , Daniel Micay , Djalal Harouni , "Dmitry V . Levin" , "Eric W . Biederman" , Greg Kroah-Hartman , Ingo Molnar , "J . Bruce Fields" , Jeff Layton , Jonathan Corbet , Kees Cook , Oleg Nesterov , Solar Designer Subject: Re: [PATCH v8 07/11] proc: flush task dcache entries from all procfs instances Message-ID: <20200210192302.GI23230@ZenIV.linux.org.uk> References: <20200210150519.538333-1-gladkov.alexey@gmail.com> <20200210150519.538333-8-gladkov.alexey@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Feb 10, 2020 at 09:46:26AM -0800, Linus Torvalds wrote: > On Mon, Feb 10, 2020 at 7:06 AM Alexey Gladkov wrote: > > > > This allows to flush dcache entries of a task on multiple procfs mounts > > per pid namespace. > > > > The RCU lock is used because the number of reads at the task exit time > > is much larger than the number of procfs mounts. > > Ok, this looks better to me than the previous version. > > But that may be the "pee-in-the-snow" effect, and I _really_ want > others to take a good look at the whole series. > > The right people seem to be cc'd, but this is pretty core, and /proc > has a tendency to cause interesting issues because of how it's > involved in a lot of areas indirectly. > > Al, Oleg, Andy, Eric? Will check tonight (ears-deep in sorting out the old branches right now)