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[209.132.180.67]) by mx.google.com with ESMTP id x8si18403747pfi.391.2017.11.24.06.07.15; Fri, 24 Nov 2017 06:07:26 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753690AbdKXOE1 (ORCPT + 76 others); 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 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DB1D17E384; Fri, 24 Nov 2017 14:04:24 +0000 (UTC) Received: from agk-dp.fab.redhat.com (agk-dp.fab.redhat.com [10.33.15.10]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2D52060F89; Fri, 24 Nov 2017 14:04:15 +0000 (UTC) Received: from agk by agk-dp.fab.redhat.com with local (Exim 4.69) (envelope-from ) id 1eIEaT-0004lB-NE; Fri, 24 Nov 2017 14:04:13 +0000 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-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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 Precedence: bulk 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 From 1584935476019304551@xxx Fri Nov 24 08:30:56 +0000 2017 X-GM-THRID: 1581761436257495082 X-Gmail-Labels: Inbox,Category Forums,HistoricalUnread