From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Lutomirski Subject: Re: [PATCH v5 8/9] vfs: Add vfs_copy_file_range() support for pagecache copies Date: Wed, 14 Oct 2015 11:53:45 -0700 Message-ID: References: <1443634014-3026-1-git-send-email-Anna.Schumaker@Netapp.com> <1443634014-3026-9-git-send-email-Anna.Schumaker@Netapp.com> <20151011142203.GA31867@infradead.org> <20151012231749.GC11398@birch.djwong.org> <561E980C.9010509@Netapp.com> <20151014182701.GC31225@infradead.org> <20151014184946.GA15214@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: In-Reply-To: <20151014184946.GA15214@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org To: Christoph Hellwig Cc: Anna Schumaker , "Darrick J. Wong" , linux-nfs@vger.kernel.org, Linux btrfs Developers List , Linux FS Devel , Linux API , Zach Brown , Al Viro , Chris Mason , Michael Kerrisk-manpages , andros@netapp.com List-Id: linux-api@vger.kernel.org On Wed, Oct 14, 2015 at 11:49 AM, Christoph Hellwig wrote: > On Wed, Oct 14, 2015 at 11:38:13AM -0700, Andy Lutomirski wrote: >> One might argue that reflink is like copy + immediate dedupe. > > Not, it's not. It's all that and more, because it is an operation that > is atomic vs other writes to the file and it's an operation that either > clones the whole range or nothing. That's a very important difference. Fair enough. Would copy_file_range without the reflink option removed still be permitted to link blocks on supported filesystems (btrfs and maybe XFS)? --Andy