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=-4.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 D7BA3C433DF for ; Thu, 9 Jul 2020 22:30:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A675B20775 for ; Thu, 9 Jul 2020 22:30:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594333836; bh=Dpn69SR1yUFPn66W7Fbbk1lCZ1fQTf5VGLdHh2L6pHU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=B8JLUhy4HZ5WIeEchINkjwiWFutg/xd1Y1udq6OclaQR+McLMgXBFWabBWYciUkAK 3Ru2Fi9c+eO/ndX3/ratZOBybEQiolt9t7OPYw+KhGPnZFEkIqmgjFcfdzFnpcFf9J wyXSn7umMRo0/i2BwRoF9ow10BPMHMe+Ao2GPGWw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726809AbgGIWag (ORCPT ); Thu, 9 Jul 2020 18:30:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:53866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726213AbgGIWag (ORCPT ); Thu, 9 Jul 2020 18:30:36 -0400 Received: from gmail.com (unknown [104.132.1.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8540B2070E; Thu, 9 Jul 2020 22:30:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594333835; bh=Dpn69SR1yUFPn66W7Fbbk1lCZ1fQTf5VGLdHh2L6pHU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=m+WR+Y2LanZRhq8MC5xduHojOk8O3+XkAMqrAcK0GJHm1Uegqx4r0qOxZTCnB4eo+ 8Pz68buk00ixvCYM+O7sDEZwr/AFjVyiAAk7rL6gakndlg3018/druWwbuN6YlXRPs fEjJFYMNpIrs+615pkKDogPMr21H+id2N31Liccg= Date: Thu, 9 Jul 2020 15:30:34 -0700 From: Eric Biggers To: Satya Tangirala Cc: linux-fscrypt@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-ext4@vger.kernel.org Subject: Re: [PATCH 4/5] ext4: support direct I/O with fscrypt using blk-crypto Message-ID: <20200709223034.GE3855682@gmail.com> References: <20200709194751.2579207-1-satyat@google.com> <20200709194751.2579207-5-satyat@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200709194751.2579207-5-satyat@google.com> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Thu, Jul 09, 2020 at 07:47:50PM +0000, Satya Tangirala wrote: > From: Eric Biggers > > Wire up ext4 with fscrypt direct I/O support. > > Signed-off-by: Eric Biggers > Signed-off-by: Satya Tangirala This commit message could use some more details. I think it should clarify that the direct I/O support is limited to cases where the filesystem has been mounted with '-o inlinecrypt' and CONFIG_BLK_INLINE_ENCRYPTION has been enabled, along with CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK if hardware support isn't present. As-is, it sounds a bit over-promising. Likewise for f2fs. We need to properly document this too. At the very least, in the fscrypt patch, Documentation/filesystems/fscrypt.rst needs to be updated because it currently says "Direct I/O is not supported on encrypted files." fscrypt.rst could also use some information about inline encryption. Currently inline encryption for fscrypt is only documented in the ext4 and f2fs documentation in the context of the inlinecrypt mount option. (Though, this suggestion applies even without direct I/O support.) - Eric