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 25C9EC43219 for ; Thu, 10 Nov 2022 15:38:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231406AbiKJPiu (ORCPT ); Thu, 10 Nov 2022 10:38:50 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55446 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229675AbiKJPis (ORCPT ); Thu, 10 Nov 2022 10:38:48 -0500 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CC58D7669; Thu, 10 Nov 2022 07:38:46 -0800 (PST) Received: from letrec.thunk.org ([12.139.153.3]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 2AAFccQA016649 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 10 Nov 2022 10:38:40 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1668094721; bh=wUJSGl619gPmorbLlIEb7nTood/eoKaRGCcIqALdWs0=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=A2yajZ6YCWkXUOOs2EAoqNS/mX+zuFXFrRpM50gtbgv+Gy9fEfhJQih4UjfHUZkr0 htWU3g6mtQBBl2ek1LwPh9sAYusMHZS+dCMCMbClppDeGt2jyYhG/rialwnoCvjGm/ S6d5fVttIOUtEivxIqOjvY01qjXbCAYHIHo+KyWmkkxhoN1I2DGTuJrtR9I/O4NlGg d18pxAxQiP3+HfuQLWI4Wl/CcndxiA8uSyNEq4Mr6RbNLyeOVeKo2UiVVZDRV5egdU ssx1t05Z4cUkfjpL6S3cP5AFgmF7CSYomuSTwo9htbd0gwTJJRYaqiu/TsTxDe7SkR IMmILw8+py6cg== Received: by letrec.thunk.org (Postfix, from userid 15806) id 791BA8C022E; Thu, 10 Nov 2022 10:38:37 -0500 (EST) Date: Thu, 10 Nov 2022 10:38:37 -0500 From: "Theodore Ts'o" To: Niels de Vos Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Xiubo Li , Marcel Lauhoff Subject: Re: [RFC 0/4] fs: provide per-filesystem options to disable fscrypt Message-ID: References: <20221110141225.2308856-1-ndevos@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221110141225.2308856-1-ndevos@redhat.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 10, 2022 at 03:12:21PM +0100, Niels de Vos wrote: > While more filesystems are getting support for fscrypt, it is useful to > be able to disable fscrypt for a selection of filesystems, while > enabling it for others. Could you say why you find it useful? Is it because you are concerned about the increased binary size of a particular file system if fscrypt is enabled? That hasn't been my experience, the hooks to call into fscrypt are small and don't add too much to any one particular file system; the bulk of the code is in fs/crypto. Is it because people are pushing buggy code that doesn't compile if you enable, say, CONFIG_FS_XXX and CONFIG_FSCRYPT at the same time? Is it because a particular distribution doesn't want to support fscrypt with a particular file system? If so, there have been plenty of file system features for say, ext4, xfs, and btrfs, which aren't supported by a distro, but there isn't a CONFIG_FS_XXX_YYY to disable that feature, nor have any distros requested such a thing --- which is good because it would be an explosion of new CONFIG parameters. Or is it something else? Note that nearly all of the file systems will only enable fscrypt if some file system feature flag enabls it. So I'm not sure what's the motivation behind adding this configuration option. If memory serves, early in the fscrypt development we did have per-file system CONFIG's for fscrypt, but we consciously removed it, just as we no longer have per-file system CONFIG's to enable or disable Posix ACL's or extended attributes, in the name of simplifying the kernel config. Cheers, - Ted