From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: New copyfile system call - discuss before LSF? Date: Thu, 21 Feb 2013 14:37:32 +0100 Message-ID: <5126231C.6060507@suse.de> References: <512606DF.5050706@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Linux FS Devel , "linux-kernel@vger.kernel.org" , "Chris L. Mason" , Christoph Hellwig , Alexander Viro , "Martin K. Petersen" To: Ric Wheeler Return-path: In-Reply-To: <512606DF.5050706@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 02/21/2013 12:37 PM, 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. > > 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. > Yeah, I remember. I talked to Mkp about it, who (as usual :-) had a=20 patchset stashed away for this. Or a preliminary attempt, anyway. However, this was waiting for the DISCARD merging patches to go in,=20 which in turn were waiting for the WRITE SAME patches IIRC. Or something. Martin? > 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 :) ? > Oh, most definitely. Now that I finally have an array capable of doing ROD token copy we should be reevaluating things. I see to have the sg_xcopy program updated to do ROD copy, then we=20 will have some real-world data. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 N=FCrnberg GF: J. Hawn, J. Guild, F. Imend=F6rffer, HRB 16746 (AG N=FCrnberg)