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=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 27FF2C433E6 for ; Fri, 12 Feb 2021 07:48:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E2B2E64E05 for ; Fri, 12 Feb 2021 07:48:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229928AbhBLHso (ORCPT ); Fri, 12 Feb 2021 02:48:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:46326 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229625AbhBLHrq (ORCPT ); Fri, 12 Feb 2021 02:47:46 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6E66064DEE; Fri, 12 Feb 2021 07:46:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1613116016; bh=V5VmSoU6jzgdBUBGYUFsqrWJOs4ufbyeLq3ulBd68Ec=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=B6yypRUVOhMMgeyh/U9LtFuNLEe6UEJ0mpIyLPj1yWUysz/TkxGifb+vrGoWItc9j eujH4jnHSfPamC6y6mvLoPfmDinJDwdO95C/SmOIHE7vrOUDRsvoBPW3Q82n/cDEfa kY+Y9o2CpyhZ3j2osBVZ7P7NnaIPpeTTbA/66Z0w= Date: Fri, 12 Feb 2021 08:46:53 +0100 From: Greg KH To: Nicolas Boichat Cc: "Darrick J . Wong" , Alexander Viro , Ian Lance Taylor , Luis Lozano , Dave Chinner , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] fs: Add flag to file_system_type to indicate content is generated Message-ID: References: <20210212044405.4120619-1-drinkcat@chromium.org> <20210212124354.1.I7084a6235fbcc522b674a6b1db64e4aff8170485@changeid> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210212124354.1.I7084a6235fbcc522b674a6b1db64e4aff8170485@changeid> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 12, 2021 at 12:44:00PM +0800, Nicolas Boichat wrote: > Filesystems such as procfs and sysfs generate their content at > runtime. This implies the file sizes do not usually match the > amount of data that can be read from the file, and that seeking > may not work as intended. > > This will be useful to disallow copy_file_range with input files > from such filesystems. > > Signed-off-by: Nicolas Boichat > --- > I first thought of adding a new field to struct file_operations, > but that doesn't quite scale as every single file creation > operation would need to be modified. Even so, you missed a load of filesystems in the kernel with this patch series, what makes the ones you did mark here different from the "internal" filesystems that you did not? This feels wrong, why is userspace suddenly breaking? What changed in the kernel that caused this? Procfs has been around for a _very_ long time :) thanks, greg k-h