From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [git pull] device mapper fix for 4.18-rc6 Date: Fri, 20 Jul 2018 18:40:46 -0400 Message-ID: <20180720224046.GA12929@redhat.com> References: <20180720191407.GA11868@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Linus Torvalds Cc: dm-devel@redhat.com, Mikulas Patocka List-Id: dm-devel.ids On Fri, Jul 20 2018 at 5:25pm -0400, Linus Torvalds wrote: > On Fri, Jul 20, 2018 at 12:14 PM Mike Snitzer wrote: > > > > Fix DM writecache target to allow an optional offset to the start of > > the data and metadata area. This allows userspace tools (e.g. LVM2) > > to place a header and metadata at the front of the writecache device > > for its use. > > "fix"? > > Not really. I hold it to be a "fix" because it was an embarassing oversight on my part. Without this, userspace support cannot be properly added. LVM2 developers raised their inability to put their metadata anywhere and I was like "oh shit". Not much point releasing the DM kernel code if it cannot be properly tied into a volume manager for persistent use across boots, etc. > But I'm a softie, and I took it. Don't do it again. Considering dm-writecache was merged for 4.18 I think it important to get it right. So thankfully you've chosen wisely ;) But I certainly sat on this change for a couple rc releases, should've gotten it to you a couple weeks ago. Thanks, Mike