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 6A3A3C2BAEE for ; Tue, 24 Mar 2020 18:48:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 417A920836 for ; Tue, 24 Mar 2020 18:48:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727672AbgCXSsK (ORCPT ); Tue, 24 Mar 2020 14:48:10 -0400 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:46184 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727365AbgCXSsK (ORCPT ); Tue, 24 Mar 2020 14:48:10 -0400 Received: from callcc.thunk.org (pool-72-93-95-157.bstnma.fios.verizon.net [72.93.95.157]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 02OIlsE5019147 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 24 Mar 2020 14:47:54 -0400 Received: by callcc.thunk.org (Postfix, from userid 15806) id 2B396420EBA; Tue, 24 Mar 2020 14:47:54 -0400 (EDT) Date: Tue, 24 Mar 2020 14:47:54 -0400 From: "Theodore Y. Ts'o" To: Peter Maydell Cc: Linus Walleij , "Suzuki K. Poulose" , Andreas Dilger , Ext4 Developers List , linux-fsdevel , Linux API , QEMU Developers , Florian Weimer , Andy Lutomirski , stable Subject: Re: [PATCH] ext4: Give 32bit personalities 32bit hashes Message-ID: <20200324184754.GG53396@mit.edu> References: <20200317113153.7945-1-linus.walleij@linaro.org> <20200324023431.GD53396@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue, Mar 24, 2020 at 09:29:58AM +0000, Peter Maydell wrote: > > On the contrary, that would be a much better interface for QEMU. > We always know when we're doing an open-syscall on behalf > of the guest, and it would be trivial to make the fcntl() call then. > That would ensure that we don't accidentally get the > '32-bit semantics' on file descriptors QEMU opens for its own > purposes, and wouldn't leave us open to the risk in future that > setting the PER_LINUX32 flag for all of QEMU causes > unexpected extra behaviour in future kernels that would be correct > for the guest binary but wrong/broken for QEMU's own internals. If using a flag set by fcntl is better for qemu, then by all means let's go with that instead of using a personality flag/number. Linus, do you have what you need to do a respin of the patch? - Ted