From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cn.fujitsu.com ([222.73.24.84]:35359 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751507AbaARFbS convert rfc822-to-8bit (ORCPT ); Sat, 18 Jan 2014 00:31:18 -0500 Message-ID: <52DA1160.50504@cn.fujitsu.com> Date: Sat, 18 Jan 2014 13:30:08 +0800 From: Wang Shilong MIME-Version: 1.0 To: dsterba@suse.cz CC: "linux-btrfs@vger.kernel.org Btrfs" Subject: Re: [PATCH] Btrfs-progs: make send/receive compatible with older kernels References: <1389264758-9495-1-git-send-email-wangsl.fnst@cn.fujitsu.com> <52CE8CDC.6030408@giantdisaster.de> <20140109121606.GI15634@carfax.org.uk> <1389279172.23310.50.camel@ret.masoncoding.com> <20140114152756.GX6498@twin.jikos.cz> In-Reply-To: <20140114152756.GX6498@twin.jikos.cz> Content-Type: text/plain; charset=UTF-8; format=flowed Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi Dave, On 01/14/2014 11:27 PM, David Sterba wrote: > On Thu, Jan 09, 2014 at 02:52:27PM +0000, Chris Mason wrote: >>> You may need to upgrade the kernel to get new features offered by a >>> new userspace, but I think we should absolutely not be changing >>> userspace in a way that makes it incompatible with older kernels. >> I'd really prefer that we maintain compatibility with the older kernels. >> Heavy btrfs usage is going to want a newer kernel anyway, but this is an >> important policy to keep in place for the future. > I agree. > >> Especially since Wang went to the trouble of making the patch, I'd >> rather take it. > What do you think about adding #ifdef's around the code? That way we'll > know that's for backwards compatibility only and up to what kernel > version. It will be easier to remove it in the far future. Sounds a good idea, would you describe it more specific so that i can give a v2.^_^ Thanks， Wang > > > david >