From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753530Ab3BUNv6 (ORCPT ); Thu, 21 Feb 2013 08:51:58 -0500 Received: from mx12.netapp.com ([216.240.18.77]:22621 "EHLO mx12.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200Ab3BUNv5 convert rfc822-to-8bit (ORCPT ); Thu, 21 Feb 2013 08:51:57 -0500 X-IronPort-AV: E=Sophos;i="4.84,709,1355126400"; d="scan'208";a="24871362" From: "Myklebust, Trond" To: Ric Wheeler CC: Linux FS Devel , "linux-kernel@vger.kernel.org" , "Chris L. Mason" , Christoph Hellwig , Alexander Viro , "Martin K. Petersen" , Hannes Reinecke Subject: Re: New copyfile system call - discuss before LSF? Thread-Topic: New copyfile system call - discuss before LSF? Thread-Index: AQHOECfzherspfmEjEqBTzfvhb3EUJiE2wAA Date: Thu, 21 Feb 2013 13:51:53 +0000 Message-ID: <4FA345DA4F4AE44899BD2B03EEEC2FA9235D998C@SACEXCMBX04-PRD.hq.netapp.com> References: <512606DF.5050706@redhat.com> In-Reply-To: <512606DF.5050706@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.104.60.115] Content-Type: text/plain; charset=US-ASCII Content-ID: <6E2A42859CBB174792185AD5B42273D4@tahoe.netapp.com> Content-Transfer-Encoding: 7BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2013-02-21 at 12:37 +0100, Ric Wheeler wrote: > We have debated the need to have a system call to allow for offloading copy > operations, for example to an NFS server (part to the new NFS 4.2 > specification), SCSI target device (two different SCSI commands do this), local > file systems (reflink, etc) and I suspect many other possible parts of the stack > could implement this. sendfile64() pretty much already has the right arguments for a "copyfile", however it would be nice to add a 'flags' parameter: the NFSv4.2 version would use that to specify whether or not to copy file metadata. > The earliest discussion of such a system call I saw happened back in 2001, I > know we had another more recent flurry (2-3 years back?) as well that got > tangled up and died away. > > Given the new popularity of this in storage devices and the use case for virt > guests, any chance to get a proposal floated this year that might be able to > land upstream in our life times :) ? I'm planning on soon dusting off the NFS prototype that NetApp wrote 3 years ago and converting at least the client implementation into something that can go upstream. We do also have a server prototype for Linux, but the copy offload between 2 different servers is a hack and would need significant work. -- Trond Myklebust Linux NFS client maintainer NetApp Trond.Myklebust@netapp.com www.netapp.com