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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,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 44C61C10DCE for ; Tue, 24 Mar 2020 21:18:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 154982070A for ; Tue, 24 Mar 2020 21:18:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="r/73bErW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727613AbgCXVSA (ORCPT ); Tue, 24 Mar 2020 17:18:00 -0400 Received: from mail-lf1-f68.google.com ([209.85.167.68]:33051 "EHLO mail-lf1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727023AbgCXVSA (ORCPT ); Tue, 24 Mar 2020 17:18:00 -0400 Received: by mail-lf1-f68.google.com with SMTP id c20so54724lfb.0 for ; Tue, 24 Mar 2020 14:17:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=nFWhs7FYWqUzfSLp89dUr9RqAyDvvxrGjpfFY3Xf6t0=; b=r/73bErWdHQvuSdWJNWD31sFM6sBzEI3plO5Ph0mnhTsKRC3h1QN3i7Fz3eKj47Yan BwWMNi7sdz1VngrNfJgVhs4otMGlVbKrH5Ojtg4qQyZl6c5KNhEt2puHDbfeP7zS1g9z 9sb9L8shr//a5jX0W9biM5R/XFXVss0aK7nJnFNfhT69yuJ3vEp20yhHEiPfGub2S0l3 eAM6WE6onEd3buLeks9BWIX5O3wweUSmc37Ts60F6+qNm0gZUEZMEVw0o0nixNUSAlOc geZpCA4tpuURui/rTdFdYUk8MNAkScEJxAEUfyVK4GkLj/8d6IGrDaMTou75bMHoukIi C9DQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=nFWhs7FYWqUzfSLp89dUr9RqAyDvvxrGjpfFY3Xf6t0=; b=cTMsKWdxYrLh1U+K0ZqUmXGQc8Is5qNjIjj3zbutEsRhvfk/sePGx62iqZky8WESGS JuyYW/PHkv+54wsagf5C4klNbAMffKtKBsySu2xdo3s/pqOe7v9bbbc+hkFYlGLrsClp d42rdVKnK7MiMCOHzffHEGqzbzLO03itKnRkXVX/y0Rl4QbZggbRhwaM5ijXVXsHvWwN bG8GoupwDGzcHgSwUVcMLce3CQHBprfPFwqBEv6KQ+eWoG+mwCO4MljyMjIWCscmPJ2J zUJroXRrbLynjFCzigX9uD12BRKOHrrzupLKfYxAmZcydRVTR+X/03KyMOBkrJxfMjOU gNsg== X-Gm-Message-State: ANhLgQ1ypQ19H2rK+aQ8rqMPVc6nYuj8PzCNLYsyG9lvc4+93ZgYAseq cln6y6ygCd4MfT8mq2d4NxxBAVhwFzj5YOT7VC/hsw== X-Google-Smtp-Source: ADFU+vu/WFfI8+Ea0qixkispTE8M2IBdFmk3vOeBjdzg2fpI2YVxUN1mkgIfe3Rc2yqBnwLXF8WOfkInLMcS8iGWzNs= X-Received: by 2002:a19:6502:: with SMTP id z2mr23818lfb.47.1585084677811; Tue, 24 Mar 2020 14:17:57 -0700 (PDT) MIME-Version: 1.0 References: <20200317113153.7945-1-linus.walleij@linaro.org> <20200324023431.GD53396@mit.edu> <20200324184754.GG53396@mit.edu> In-Reply-To: <20200324184754.GG53396@mit.edu> From: Linus Walleij Date: Tue, 24 Mar 2020 22:17:46 +0100 Message-ID: Subject: Re: [PATCH] ext4: Give 32bit personalities 32bit hashes To: "Theodore Y. Ts'o" Cc: Peter Maydell , "Suzuki K. Poulose" , Andreas Dilger , Ext4 Developers List , linux-fsdevel , Linux API , QEMU Developers , Florian Weimer , Andy Lutomirski , stable Content-Type: text/plain; charset="UTF-8" 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 7:48 PM Theodore Y. Ts'o wrote: > 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? Absolutely, I'm a bit occupied this week but I will try to get to it early next week! Thanks a lot for the directions here, it's highly valuable. Yours, Linus Walleij