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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT 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 E1AFEC04EB9 for ; Sat, 1 Dec 2018 22:36:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9F0212081D for ; Sat, 1 Dec 2018 22:36:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9F0212081D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nfs-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725751AbeLBJty (ORCPT ); Sun, 2 Dec 2018 04:49:54 -0500 Received: from ipmail06.adl2.internode.on.net ([150.101.137.129]:9439 "EHLO ipmail06.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725748AbeLBJty (ORCPT ); Sun, 2 Dec 2018 04:49:54 -0500 Received: from ppp59-167-129-252.static.internode.on.net (HELO dastard) ([59.167.129.252]) by ipmail06.adl2.internode.on.net with ESMTP; 02 Dec 2018 09:06:18 +1030 Received: from dave by dastard with local (Exim 4.80) (envelope-from ) id 1gTDs1-0001LN-L7; Sun, 02 Dec 2018 09:36:17 +1100 Date: Sun, 2 Dec 2018 09:36:17 +1100 From: Dave Chinner To: Matthew Wilcox Cc: Olga Kornievskaia , bfields@redhat.com, linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v2 01/10] VFS generic copy_file_range() support Message-ID: <20181201223617.GR19305@dastard> References: <20181130200348.59524-1-olga.kornievskaia@gmail.com> <20181130200348.59524-2-olga.kornievskaia@gmail.com> <20181201211806.GO10377@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181201211806.GO10377@bombadil.infradead.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org On Sat, Dec 01, 2018 at 01:18:06PM -0800, Matthew Wilcox wrote: > On Fri, Nov 30, 2018 at 03:03:39PM -0500, Olga Kornievskaia wrote: > > Relax the condition that input files must be from the same > > file systems. > > > + ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out, > > + count > MAX_RW_COUNT ? MAX_RW_COUNT : count, 0); > > Wasn't there a concern about splicing between filesystems with different > block sizes mentioned the last time this came up? I can't find a citation > for that now. the filesystems should be able to handle that themselves - they are just passes an iter that has a range of data regions in pages that they copy the required data into/out of. The data transfer mechanism itself is completely independent of filesystem block sizes.... There's lots of other problems with do_splice_direct, but I don't think this is one of them. I coul dbe wrong - this code has pretty much zero documentation on how it is supposed to work and what it is supposed to do - so don't take my word for it... Cheers, Dave. -- Dave Chinner david@fromorbit.com