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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 7E513ECE560 for ; Mon, 17 Sep 2018 21:32:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B47620867 for ; Mon, 17 Sep 2018 21:32:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2B47620867 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728556AbeIRDBy (ORCPT ); Mon, 17 Sep 2018 23:01:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55876 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727329AbeIRDBy (ORCPT ); Mon, 17 Sep 2018 23:01:54 -0400 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 420AF307D851; Mon, 17 Sep 2018 21:32:46 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-123-84.rdu2.redhat.com [10.10.123.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id EF8471C95D; Mon, 17 Sep 2018 21:32:44 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <153685389564.14766.11306559824641824935.stgit@warthog.procyon.org.uk> <153685392942.14766.3347355712333618914.stgit@warthog.procyon.org.uk> <20180914041831.GY19965@ZenIV.linux.org.uk> To: Trond Myklebust Cc: dhowells@redhat.com, "viro@ZenIV.linux.org.uk" , "linux-kernel@vger.kernel.org" , "linux-afs@lists.infradead.org" , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH 04/10] iov_iter: Add mapping and discard iterator types MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <5763.1537219964.1@warthog.procyon.org.uk> Date: Mon, 17 Sep 2018 22:32:44 +0100 Message-ID: <5764.1537219964@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.48]); Mon, 17 Sep 2018 21:32:46 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Trond Myklebust wrote: > Another question that is relevant for most networked filesystems > (including AFS, I believe), is how will you deal with encryption of the > data you are transmitting? Encrypting and decrypting in-place directly > in the page cache or in a userspace O_DIRECT mapped buffer might not be > the best and most secure option, so won't you find yourself wanting to > copy the data anyway? For kAFS, the interface between kAFS and AF_RXRPC takes an iterator. Currently, encryption is done in place on the sk_buffs inside AF_RXRPC, but the goal I have in mind is to use the crypto operation to replace the copy between sk_buff and buffer. This is tricky, however, as the encrypted payload contains metadata as well as data and on reception I have to read the metadata to find out how much data there actually is. David