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=-3.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 13693C4363D for ; Tue, 22 Sep 2020 13:57:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91E1320719 for ; Tue, 22 Sep 2020 13:57:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=szeredi.hu header.i=@szeredi.hu header.b="oZkDdTCn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726621AbgIVN47 (ORCPT ); Tue, 22 Sep 2020 09:56:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60938 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726593AbgIVN47 (ORCPT ); Tue, 22 Sep 2020 09:56:59 -0400 Received: from mail-ua1-x942.google.com (mail-ua1-x942.google.com [IPv6:2607:f8b0:4864:20::942]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 89478C061755 for ; Tue, 22 Sep 2020 06:56:59 -0700 (PDT) Received: by mail-ua1-x942.google.com with SMTP id v5so5504342uau.10 for ; Tue, 22 Sep 2020 06:56:59 -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; bh=0la+NjqOspuYNFekbQHmZdYeJ/vAjkgTC2efPzMN2FI=; b=oZkDdTCnD0YA6UlQCZOdKL1o6Snt49DpVTtDbTUtiNUB2ibOzVFtkhfZYws5Q+uTyj wXwLH8g7BAQg9kiy9OdkW2tr+4O1AoenLldp1JfhnJaMSy84vDWemPA3wM7uKuv0J6M5 wy7O2ia4ODWZEjj3lbSv67qtxbjt4ChMTVhU4= 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=0la+NjqOspuYNFekbQHmZdYeJ/vAjkgTC2efPzMN2FI=; b=TuF3V0sStEnIC/RBjVWGGBoYz3F5F624WLVtavCq1b9MnRGPJSjuhM1Os05kbyA1R4 MjeQXPNvGIBUCPZ7sxJUNeoOk0wTdFoEu2OCgRCao1+t+0FOBgHZqTLPbkIFr5eS8jEH 44PWS4N/WMSJU98WEd1Zb+xom/9u5fUbRZ2JjC/XCCkoaU+D88GbJWuoQvkVwpBXK9cP A0z9AeRtE0y4chaSY33aSUhYovGBqb7FHDeoW399MWaq7/syXTCjv3YcQlREPVdwv7sp k3HOOmsokkJOBWjXbZJOSA2RJFPOkI6LEl6UqwzMkhIH5tw+LX+UpRxxkU3hUkQHVAiQ 6P/w== X-Gm-Message-State: AOAM531z4TSqhtr5BJ+yBTpmhpCe7wWWhj8MtHJ4eFma4INMB267RopC iiZtsWdhdY6krXq67yhTkPqWxi5P3VOlVsnZqKi+YA== X-Google-Smtp-Source: ABdhPJx92MkTzhFs4x7X3E6tPCJGH1Fl6XNrTKUq1ToFvbJQKVAZRoz9N3FWn+9mYnR/nJkn/Oj9IKETHh3YU3Jssm8= X-Received: by 2002:ab0:ef:: with SMTP id 102mr3037429uaj.142.1600783018711; Tue, 22 Sep 2020 06:56:58 -0700 (PDT) MIME-Version: 1.0 References: <20200916161737.38028-1-vgoyal@redhat.com> <20200916161737.38028-5-vgoyal@redhat.com> In-Reply-To: <20200916161737.38028-5-vgoyal@redhat.com> From: Miklos Szeredi Date: Tue, 22 Sep 2020 15:56:47 +0200 Message-ID: Subject: Re: [PATCH v2 4/6] fuse: Kill suid/sgid using ATTR_MODE if it is not truncate To: Vivek Goyal Cc: linux-fsdevel@vger.kernel.org, virtio-fs-list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Sep 16, 2020 at 6:18 PM Vivek Goyal wrote: > But if this is non-truncate setattr then server will not kill suid/sgid. > So continue to send ATTR_MODE to kill suid/sgid for non-truncate setattr, > even if ->handle_killpriv_v2 is enabled. Sending ATTR_MODE doesn't make sense, since that is racy. The refresh-recalculate makes the race window narrower, but it doesn't eliminate it. I think I suggested sending write synchronously if suid/sgid/caps are set. Do you see a problem with this? Does this affect anything other than cached writes? Thanks, Miklos