Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-fx0-f46.google.com ([209.85.161.46]:46551 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755459Ab1LNTWN (ORCPT ); Wed, 14 Dec 2011 14:22:13 -0500 Message-ID: <4EE8F75F.6070800@gmail.com> Date: Wed, 14 Dec 2011 14:22:07 -0500 From: Ric Wheeler MIME-Version: 1.0 To: "linux-scsi@vger.kernel.org" , linux-fsdevel , Hannes Reinecke , Andrew Morton , linux-nfs@vger.kernel.org, Joel Becker , James Bottomley Subject: copy offload support in Linux - new system call needed? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: Back at LinuxCon Prague, we talked about the new NFS and SCSI commands that let us offload copy operations to a storage device (like an NFS server or storage array). This got new life in the virtual machine world where you might want to clone bulky guest files or ranges of blocks and was driven through the standards bodies by vmware, microsoft and some of the major storage vendors. Windows8 has this functionality fully coded and integrated in the GUI, I assume vmware also uses it and there are some vendors who announced support at the SNIA SDC conference. We had an active thread a couple of years back that came out of the reflink work and, at the time, there seemed to be moderately positive support for adding a new system call that would fit this use case (Joel Becker's copyfile()). Can we resurrect this effort? Is copyfile() still a good way to go, or should we look at other hooks? Thanks! Ric