From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?P=E1draig_Brady?= Subject: Re: VFS support for fast copy on deduplicating FSes Date: Thu, 25 Nov 2010 10:50:31 +0000 Message-ID: <4CEE3F77.4020206@draigBrady.com> References: <20101125103258.GA16562@mother.pipebreaker.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Linux Kernel Mailing List , BTRFS MAILING LIST Return-path: In-Reply-To: <20101125103258.GA16562@mother.pipebreaker.pl> List-ID: On 25/11/10 10:32, Tomasz Torcz wrote: > On Thu, Nov 25, 2010 at 04:19:17AM -0600, David Nicol wrote: >> unresearched question/suggestion: >> >> Is there general support for a "fast copy" ioctl in the VFS layer, >> which would be hooked by file systems that support COW or other form= s >> of deduplication and can provide copy semantics by manipulating >> metadata only? >> >=20 > Yes, see reflink(2) syscall (http://lwn.net/Articles/331576/). >=20 Yep and this: http://lwn.net/Articles/335380/ Note that cp --reflink has been supported for a while, but it's BTRFS specific at the moment. We'll need to change to the more generic interface. cheers, P=E1draig. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752610Ab0KYKvx (ORCPT ); Thu, 25 Nov 2010 05:51:53 -0500 Received: from mail1.slb.deg.dub.stisp.net ([84.203.253.98]:5107 "HELO mail1.slb.deg.dub.stisp.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752393Ab0KYKvv (ORCPT ); Thu, 25 Nov 2010 05:51:51 -0500 Message-ID: <4CEE3F77.4020206@draigBrady.com> Date: Thu, 25 Nov 2010 10:50:31 +0000 From: =?ISO-8859-1?Q?P=E1draig_Brady?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: Linux Kernel Mailing List , BTRFS MAILING LIST Subject: Re: VFS support for fast copy on deduplicating FSes References: <20101125103258.GA16562@mother.pipebreaker.pl> In-Reply-To: <20101125103258.GA16562@mother.pipebreaker.pl> X-Enigmail-Version: 1.0.1 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/11/10 10:32, Tomasz Torcz wrote: > On Thu, Nov 25, 2010 at 04:19:17AM -0600, David Nicol wrote: >> unresearched question/suggestion: >> >> Is there general support for a "fast copy" ioctl in the VFS layer, >> which would be hooked by file systems that support COW or other forms >> of deduplication and can provide copy semantics by manipulating >> metadata only? >> > > Yes, see reflink(2) syscall (http://lwn.net/Articles/331576/). > Yep and this: http://lwn.net/Articles/335380/ Note that cp --reflink has been supported for a while, but it's BTRFS specific at the moment. We'll need to change to the more generic interface. cheers, Pádraig.