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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 72194C43334 for ; Mon, 18 Jul 2022 12:21:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235039AbiGRMVd (ORCPT ); Mon, 18 Jul 2022 08:21:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235038AbiGRMVb (ORCPT ); Mon, 18 Jul 2022 08:21:31 -0400 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 532DC25287 for ; Mon, 18 Jul 2022 05:21:29 -0700 (PDT) Received: by mail-ej1-x633.google.com with SMTP id j22so20889103ejs.2 for ; Mon, 18 Jul 2022 05:21:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=szeredi.hu; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=ie8y8xom7gdgORK3/wgC6v2nBY/N6LA9J5NWgTDl2HM=; b=dZ9jScMt4MO13dtuzooZqTSxO2bjJkLycwSI6B0TBmg9pnUReCQ76CmaV4WQ6A5J1F BXd0HR3D0YzUSUo21ICIN4NsTAl3SmzYXTrgawKRuq35PsRaR1GgaemH76YDIv0NQeDv D1EK/PliBPHo5GdlCRd296v+4mVWyx5UzS/OI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=ie8y8xom7gdgORK3/wgC6v2nBY/N6LA9J5NWgTDl2HM=; b=Id8tWZogbwf/Kw2me/CNZ3j9OlS1+rEyiBAfvic6qemTqsURurBgS0CTz2TD9F2fNd zidYvPQu7OUEopxy1ugsKoLvVgOgEPGWj3q8VcnuC4rCcTUcSHy9zuiavkB4Pghrjj+G DayLMDuv0czCK2nePdNYB4mY2MCzJsb6dJOk+9Igv+bOlybqIjxEXr6BFuMDz7C4rGxm QpjAgqo8czBGVVJJFe62aEHS29wt0/Vq2kKUKzrT/6y2kT3evdwl6Xl6jrS1M5EdVoTB fwuqGC38T3lYdMlSPo/oU28WXo6ixwfnK1KwksW3p4M7sp2AijJ0vIRgyF/1MdGabe8q Vq+g== X-Gm-Message-State: AJIora8rearovkBqRAwZWzY/JgSlD8HsspQyEAaxFh1oN/OvCfZH25Aw BRawRr/vTrd3s5DQB8M95nqzKIH/61Sp/F+PtgktwA== X-Google-Smtp-Source: AGRyM1vI/im93ImHCgZ05iECidEYFcWtEzzcaF2dJOWQB1/Yq5IMa3L6gYgLFbipMZiZCi+5b2lvg6oArb2FqBJ9MTI= X-Received: by 2002:a17:906:93ef:b0:72b:44e2:bdd8 with SMTP id yl15-20020a17090693ef00b0072b44e2bdd8mr25545654ejb.192.1658146887863; Mon, 18 Jul 2022 05:21:27 -0700 (PDT) MIME-Version: 1.0 References: <4B9D76D5-C794-4A49-A76F-3D4C10385EE0@kohlschutter.com> <83A29F9C-1A91-4753-953A-0C98E8A9832C@kohlschutter.com> In-Reply-To: From: Miklos Szeredi Date: Mon, 18 Jul 2022 14:21:16 +0200 Message-ID: Subject: Re: [PATCH] ovl: Handle ENOSYS when fileattr support is missing in lower/upper fs To: =?UTF-8?Q?Christian_Kohlsch=C3=BCtter?= Cc: overlayfs , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-unionfs@vger.kernel.org On Mon, 18 Jul 2022 at 12:56, Christian Kohlsch=C3=BCtter wrote: > However, users of fuse that have no business with overlayfs suddenly see = their ioctl return ENOTTY instead of ENOSYS. And returning ENOTTY is the correct behavior. See this comment in : /* * This error code is special: arch syscall entry code will return * -ENOSYS if users try to call a syscall that doesn't exist. To keep * failures of syscalls that really do exist distinguishable from * failures due to attempts to use a nonexistent syscall, syscall * implementations should refrain from returning -ENOSYS. */ #define ENOSYS 38 /* Invalid system call number */ Thanks, Miklos