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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 29356C43464 for ; Mon, 21 Sep 2020 04:30:05 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4C9E520866 for ; Mon, 21 Sep 2020 04:30:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4C9E520866 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4Bvs152rGrzDqfH for ; Mon, 21 Sep 2020 14:30:01 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4BvrzK2kDPzDqf5 for ; Mon, 21 Sep 2020 14:28:23 +1000 (AEST) Received: by verein.lst.de (Postfix, from userid 2407) id 979FC68AFE; Mon, 21 Sep 2020 06:28:15 +0200 (CEST) Date: Mon, 21 Sep 2020 06:28:15 +0200 From: Christoph Hellwig To: Andy Lutomirski Subject: Re: [PATCH 1/9] kernel: add a PF_FORCE_COMPAT flag Message-ID: <20200921042815.GA16281@lst.de> References: <20200918124533.3487701-1-hch@lst.de> <20200918124533.3487701-2-hch@lst.de> <20200920151510.GS32101@casper.infradead.org> <20200920180742.GN3421308@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-aio , "open list:MIPS" , David Howells , Linux-MM , keyrings@vger.kernel.org, sparclinux , Christoph Hellwig , linux-arch , linux-s390 , Linux SCSI List , X86 ML , Matthew Wilcox , Arnd Bergmann , linux-block , Al Viro , io-uring@vger.kernel.org, linux-arm-kernel , Jens Axboe , Parisc List , Network Development , LKML , LSM List , Linux FS Devel , Andrew Morton , linuxppc-dev Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Sun, Sep 20, 2020 at 12:14:49PM -0700, Andy Lutomirski wrote: > I wonder if this is really quite cast in stone. We could also have > FMODE_SHITTY_COMPAT and set that when a file like this is *opened* in > compat mode. Then that particular struct file would be read and > written using the compat data format. The change would be > user-visible, but the user that would see it would be very strange > indeed. > > I don't have a strong opinion as to whether that is better or worse > than denying io_uring access to these things, but at least it moves > the special case out of io_uring. open could have happened through an io_uring thread a well, so I don't see how this would do anything but move the problem to a different place. > > --Andy ---end quoted text---