From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from zimbra13.linbit.com (zimbra.linbit.com [212.69.161.123]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 40835101E04D for ; Tue, 23 Sep 2014 13:03:49 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by zimbra13.linbit.com (Postfix) with ESMTP id 35B73310B89 for ; Tue, 23 Sep 2014 13:03:49 +0200 (CEST) Received: from zimbra13.linbit.com ([127.0.0.1]) by localhost (zimbra13.linbit.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id aXjYrMpi63cW for ; Tue, 23 Sep 2014 13:03:49 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by zimbra13.linbit.com (Postfix) with ESMTP id 1C7E5310B6E for ; Tue, 23 Sep 2014 13:03:49 +0200 (CEST) Received: from zimbra13.linbit.com ([127.0.0.1]) by localhost (zimbra13.linbit.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id vRkUl2Wukvk7 for ; Tue, 23 Sep 2014 13:03:49 +0200 (CEST) Received: from soda.linbit (tuerlsteher.linbit.com [86.59.100.100]) by zimbra13.linbit.com (Postfix) with ESMTPS id E6E80310B08 for ; Tue, 23 Sep 2014 13:03:48 +0200 (CEST) Date: Tue, 23 Sep 2014 13:03:48 +0200 From: Lars Ellenberg To: drbd-dev@lists.linbit.com Message-ID: <20140923110348.GA19076@soda.linbit> References: <20140919094909.GA21578@schiffbauer.net> <20140919144805.GS13125@soda.linbit> <20140919151653.GH21578@schiffbauer.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140919151653.GH21578@schiffbauer.net> Subject: Re: [Drbd-dev] drbd 8.4.3: refcounter overflow on re-sync List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Sep 19, 2014 at 05:16:53PM +0200, Marc Schiffbauer wrote: > * Lars Ellenberg schrieb am 19.09.14 um 16:48 Uhr: > >On Fri, Sep 19, 2014 at 11:49:09AM +0200, Marc Schiffbauer wrote: > >>Hi, > >> > > > >If you resolve that to a code line, > >I may be able to figure out what PAX is talking about. > > > >But from this stack trace alone, I have absolutely no idea what PAX > >is trying to say, which refcount could possibly be meant there, > >let alone why it could possibly overflow or. > > > >Ah, ok. Looking at [1], "PaX Team" says: > >.--- > >| after having looked at the drbd code a bit i think this could be a > >| real bug in drbd but only upstream can tell for sure so you'll have to > >| contact them. you can show them the following that i figured out so far: > >| > >| the refcount overflow was detected in > >| drivers/block/drbd/drbd_bitmap.c:bm_page_io_async at the > >| > >| atomic_add(len >> 9, &mdev->rs_sect_ev) > > > >Well, yes, why would it not overflow. > >It is *not* a refcount. > >It is an atomic counter. > >It is meant to overflow. > > Ok, then I can report this back and it should be fixed in PaX as a > false postive. Thanks for clarifying this. I still don't get why PAX is even sending a signal there. How could sending a signal possibly help against an overflowing counter? Ah well. I don't need to get everything ... Thanks, Lars