From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: Bcache Date: Thu, 15 Mar 2012 21:45:53 -0400 Message-ID: <20120316014552.GA24834@redhat.com> References: <20120314133228.GA2284@dhcp-172-18-216-138.mtv.corp.google.com> <20120314155339.GC30235@redhat.com> <20120314220150.GA15464@redhat.com> <20120315172746.GC8638@dhcp-172-18-216-138.mtv.corp.google.com> <20120315201732.GA23403@redhat.com> <20120315225952.GA8564@dhcp-172-18-216-138.mtv.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx1.redhat.com ([209.132.183.28]:1026 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753480Ab2CPBqJ (ORCPT ); Thu, 15 Mar 2012 21:46:09 -0400 Content-Disposition: inline In-Reply-To: <20120315225952.GA8564@dhcp-172-18-216-138.mtv.corp.google.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Kent Overstreet Cc: Vivek Goyal , lsf-pc@lists.linux-foundation.org, nauman@google.com, linux-scsi@vger.kernel.org, dm-devel@redhat.com, Christoph Hellwig On Thu, Mar 15 2012 at 6:59pm -0400, Kent Overstreet wrote: > On Thu, Mar 15, 2012 at 04:17:32PM -0400, Mike Snitzer wrote: > > Your interest should be in getting the hard work you've put into bcache > > upstream. That's unlikely to happen until you soften on your reluctance > > to embrace existing appropriate kernel interfaces. > > I don't really care what you think my priorities should be. I write code > first and foremost for myself, and the one thing I care about is good > code. > > I'd love to have bcache in mainline, seeing more use and getting more > improvements - but if that's contingent on making it work through dm, > sorry, not interested. > > If you want to convince me that dm is the right way to go you'll have > much better luck with technical arguments. We have quite a lot of code that illustrates how to implement DM targets. DM isn't forcing undue or cumbersome constraints that prevent it's use for complex targets with in-kernel metadata -- again dm-thinp proves this. It is your burden to even begin to substantiate _why_ both DM and MD are inadequate frameworks for virtual block device drivers. > > Baseless and unspecific assertions don't help your cause -- dm-thinp > > disproves your unconvincing position (manages it's metadata in kernel, > > etc). > > I'm not the only one who's read the dm code and found it lacking - and > anyways, I'm not really out to convince anyone. Like other kernel code, DM is approachable for those who are willing to put the time in to understand it. Your hand-waving (and now proxy) critiques leave us nothing to work with. > > > Kind of presumptuous, don't you think? > > > > Not really, considering what I'm responding to at the moment ;) > > Maybe you should consider how you word things... Say what? Nice projection. Luckily the thread is public for all to see. I initially thought Christoph's feedback in this thread was harsh; now it seems eerily prophetic. Lets stop wasting our time on this thread. Maybe we can be more constructive in the future.