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=-3.8 required=3.0 tests=BAYES_00, 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 C6D4FC433F5 for ; Fri, 3 Sep 2021 18:32:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AEC8A60724 for ; Fri, 3 Sep 2021 18:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347939AbhICSds (ORCPT ); Fri, 3 Sep 2021 14:33:48 -0400 Received: from zeniv-ca.linux.org.uk ([142.44.231.140]:48934 "EHLO zeniv-ca.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346181AbhICSdq (ORCPT ); Fri, 3 Sep 2021 14:33:46 -0400 Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mMDso-000qie-AY; Fri, 03 Sep 2021 18:25:46 +0000 Date: Fri, 3 Sep 2021 18:25:46 +0000 From: Al Viro To: Linus Torvalds Cc: Andreas Gruenbacher , Christoph Hellwig , "Darrick J. Wong" , Paul Mackerras , Jan Kara , Matthew Wilcox , cluster-devel , linux-fsdevel , Linux Kernel Mailing List , ocfs2-devel@oss.oracle.com, kvm-ppc@vger.kernel.org Subject: Re: [PATCH v7 00/19] gfs2: Fix mmap + page fault deadlocks Message-ID: References: <20210827164926.1726765-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 03, 2021 at 08:52:00AM -0700, Linus Torvalds wrote: > On Wed, Sep 1, 2021 at 12:53 PM Andreas Gruenbacher wrote: > > > > So there's a minor merge conflict between Christoph's iomap_iter > > conversion and this patch queue now, and I should probably clarify the > > description of "iomap: Add done_before argument to iomap_dio_rw" that > > Darrick ran into. Then there are the user copy issues that Al has > > pointed out. Fixing those will create superficial conflicts with this > > patch queue, but probably nothing serious. > > > > So how should I proceed: do you expect a v8 of this patch queue on top > > of the current mainline? > > So if you rebase for fixes, it's going to be a "next merge window" thing again. > > Personally, I'm ok with the series as is, and the conflict isn't an > issue. So I'd take it as is, and then people can fix up niggling > issues later. > > But if somebody screams loudly.. FWIW, my objections regarding the calling conventions are still there. Out of 3 callers that do want more than "success/failure", one is gone (series by tglx) and one more is broken (regardless of the semantics, btrfs on arm64). Which leaves 1 caller (fault-in for read in FPU handling on x86 sigreturn). That caller turns out to be correct, but IMO there are fairly strong arguments in favour of *not* using the normal fault-in in that case. "how many bytes can we fault in" is misleading, unless we really poke into every cacheline in the affected area. Which might be a primitive worth having, but it's a lot heavier than needed by the majority of callers.