From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48437) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cfn9j-00043l-F8 for qemu-devel@nongnu.org; Mon, 20 Feb 2017 07:33:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cfn9i-0006Nm-CA for qemu-devel@nongnu.org; Mon, 20 Feb 2017 07:33:27 -0500 Date: Mon, 20 Feb 2017 12:33:14 +0000 From: "Daniel P. Berrange" Message-ID: <20170220123314.GL15874@redhat.com> Reply-To: "Daniel P. Berrange" References: <20170203120254.15062-1-berrange@redhat.com> <20170203120254.15062-4-berrange@redhat.com> <5c7df424-d78e-650f-3045-c87fd645b611@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <5c7df424-d78e-650f-3045-c87fd645b611@redhat.com> Subject: Re: [Qemu-devel] [PATCH v2 3/6] qemu-img: add support for conv=nocreat, notrunc args to dd command List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Max Reitz Cc: qemu-devel@nongnu.org, qemu-block@nongnu.org, Kevin Wolf , Eric Blake , Fam Zheng On Fri, Feb 03, 2017 at 10:44:46PM +0100, Max Reitz wrote: > On 03.02.2017 13:02, Daniel P. Berrange wrote: > > The -n arg to the convert command allows use of a pre-existing image, > > rather than creating a new image. This adds equivalent functionality > > to the dd command using the 'conv' arg. If 'conv=nocreat' is used, > > then it will assume the image already exists. The existing image > > will be truncated to match the required output size. 'conv=notrunc' > > cna be used to preserve the existing image size. > > > > Signed-off-by: Daniel P. Berrange > > --- > > qemu-img-cmds.hx | 4 +- > > qemu-img.c | 137 +++++++++++++++++++++++++++++++++++++++++-------------- > > qemu-img.texi | 10 +++- > > 3 files changed, 115 insertions(+), 36 deletions(-) > > Quite frankly I don't like this patch very much. It's not bad in itself, > but I don't like the idea of giving qemu-img dd new features until it's > an interface for qemu-img convert. Everything that we add now encourages > new users to use it and will make the conversion a bit more difficult. > > As long as qemu-img convert gets a --target-image-opts, I don't think we > need all of this functionality in qemu-img dd. > > Anyway, I won't block/NACK this patch, so resuming review. I'm going to drop this patch and focus on just fixing qemu-img convert for now. We can re-visit 'dd' at a later date, once it is clear what will happen to it wrt refactoring to run above 'convert'. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :|