From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: [PATCH v2] dm thin: Fix bug wrt FUA request completion Date: Fri, 15 Feb 2019 10:16:55 -0500 Message-ID: <20190215151655.GB20900@redhat.com> References: <20190214232138.25667-1-ntsironis@arrikto.com> <20190215135406.GA23097@reti> 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: Nikos Tsironis Cc: ejt@redhat.com, dm-devel@redhat.com, agk@redhat.com List-Id: dm-devel.ids On Fri, Feb 15 2019 at 9:33am -0500, Nikos Tsironis wrote: > On 2/15/19 3:54 PM, Joe Thornber wrote: > > Ack. > > > > Thanks for this I was under the mistaken impression that FUA requests got split > > by core dm into separate payload and PREFLUSH requests. > > > > I've audited dm-cache and that looks ok. > > > > How did you test this patch? That missing bio_list_init() in V1 must > > have caused memory corruption? > > > > - Joe > > Hi Joe, > > bio_list_init() initializes the bio list's head and tail pointers to > NULL and pool_create() allocates the struct pool structure using > kzalloc() so the bio list was implicitly correctly initialized and no > memory corruption occurred. Yes, exactly right. v1 tested fine for me, so when I saw v2 I reasoned through why the bio_list_init() wasn't an issue and it is like you've said (kzalloc() saved us). Can you help us understand how you identified this issue? Did you have corruption after crash/powerfail and got to looking closer? Thanks, Mike