From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: [PATCH] dm-raid: add RAID discard support Date: Thu, 02 Oct 2014 21:09:49 -0400 Message-ID: References: <1411491106-23676-1-git-send-email-heinzm@redhat.com> <20140924093308.120fe616@notabene.brown> <7C39EB56-623A-4318-A558-258ABA32FF12@redhat.com> <20140924142157.33475baa@notabene.brown> <5422A4C4.4020707@redhat.com> <20141001125625.1e0d356a@notabene.brown> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20141001125625.1e0d356a@notabene.brown> (NeilBrown's message of "Wed, 1 Oct 2014 12:56:25 +1000") List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: NeilBrown Cc: Heinz Mauelshagen , device-mapper development , Shaohua Li , "Martin K. Petersen" List-Id: dm-devel.ids >>>>> "Neil" == NeilBrown writes: Neil> I would really rather that discard_zeroes_data were only set on Neil> devices where it was actually true. Then it wouldn't be my Neil> problem any more. Yeah. It's too late for 3.18 but I'll try to get a whitelist going for 3.19. Neil> Here is a question: if a region has been discarded, are we Neil> guaranteed that reads are at least stable. i.e. if I read twice Neil> will I definitely get the same value? If discard_zeroes_data=1, then yes. -- Martin K. Petersen Oracle Linux Engineering