From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753711AbdKXOE1 (ORCPT ); Fri, 24 Nov 2017 09:04:27 -0500 Received: from mx1.redhat.com ([209.132.183.28]:46370 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751286AbdKXOEZ (ORCPT ); Fri, 24 Nov 2017 09:04:25 -0500 Date: Fri, 24 Nov 2017 14:04:13 +0000 From: Alasdair G Kergon To: "Reshetova, Elena" Cc: Zdenek Kabelac , "dm-devel@redhat.com" , "linux-bcache@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-raid@vger.kernel.org" , "kent.overstreet@gmail.com" , "koverstreet@google.com" , "ejt@redhat.com" , "snitzer@redhat.com" , "shli@kernel.org" , "agk@redhat.com" , "peterz@infradead.org" , "keescook@chromium.org" Subject: Re: [PATCH 4/4] dm: convert table_device.count from atomic_t to refcount_t Message-ID: <20171124140413.GG5952@agk-dp.fab.redhat.com> Mail-Followup-To: "Reshetova, Elena" , Zdenek Kabelac , "dm-devel@redhat.com" , "linux-bcache@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-raid@vger.kernel.org" , "kent.overstreet@gmail.com" , "koverstreet@google.com" , "ejt@redhat.com" , "snitzer@redhat.com" , "shli@kernel.org" , "agk@redhat.com" , "peterz@infradead.org" , "keescook@chromium.org" References: <1508485059-21881-1-git-send-email-elena.reshetova@intel.com> <1508485059-21881-5-git-send-email-elena.reshetova@intel.com> <92f8c04f-ef1a-c41b-e82f-8d68a3ec84b5@redhat.com> <2236FBA76BA1254E88B949DDB74E612B802C1F4D@IRSMSX102.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2236FBA76BA1254E88B949DDB74E612B802C1F4D@IRSMSX102.ger.corp.intel.com> Organization: Red Hat UK Ltd. Registered in England and Wales, number 03798903. Registered Office: Peninsular House, 30-36 Monument Street, 4th Floor, London, England, EC3R 8NB. User-Agent: Mutt/1.5.18 (2008-05-17) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 24 Nov 2017 14:04:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 24, 2017 at 08:29:42AM +0000, Reshetova, Elena wrote: > By looking at the code, I don't see where the change in the reference counting > could have caused this. The cause was the bug I identified in patch 3, not this patch. The regression is easily hit - tables that reference the same underlying device more than once are very common. Alasdair