From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: uas: kernel BUG at block/blk-tag.c:89 is back again :| Date: Tue, 08 Jul 2014 13:40:45 +0200 Message-ID: <53BBD8BD.3040600@kernel.dk> References: <53B2B4B2.8050100@redhat.com> <20140703060135.GA5292@infradead.org> <53B93FE3.8050607@redhat.com> <20140707101015.GB3544@infradead.org> <53BA95C0.3020607@redhat.com> <20140708095317.GA4306@infradead.org> <53BBBFC6.2030205@kernel.dk> <20140708095619.GA11196@infradead.org> <53BBC98C.4070004@kernel.dk> <53BBD51A.4070704@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-wi0-f171.google.com ([209.85.212.171]:44793 "EHLO mail-wi0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754487AbaGHLkt (ORCPT ); Tue, 8 Jul 2014 07:40:49 -0400 Received: by mail-wi0-f171.google.com with SMTP id f8so316828wiw.4 for ; Tue, 08 Jul 2014 04:40:48 -0700 (PDT) In-Reply-To: <53BBD51A.4070704@redhat.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Hans de Goede , Christoph Hellwig Cc: "James E.J. Bottomley" , Sarah Sharp , linux-scsi@vger.kernel.org On 2014-07-08 13:25, Hans de Goede wrote: > Hi, > > On 07/08/2014 12:35 PM, Jens Axboe wrote: >> On 2014-07-08 11:56, Christoph Hellwig wrote: >>> On Tue, Jul 08, 2014 at 11:54:14AM +0200, Jens Axboe wrote: >>>>> I've posted the patch in reply to another report and added Jens to the >>>>> Cc list. As the block maintainer he need to review and merge it. >>>> >>>> Which patch is this? >>> >>> This one: >>> >>> --- >>> From: Christoph Hellwig >>> Subject: block: don't assume last put of shared tags is for the host >>> >>> There is no inherent reason why the last put of a tag structure must be >>> the one for the Scsi_Host, as device model objects can be held for >>> arbitrary periods. Merge blk_free_tags and __blk_free_tags into a single >>> funtion that just release a references and get rid of the BUG() when the >>> host reference wasn't the last. >> >> Thanks, applied. I don't think I was ever CC'ed on this one, though. > > Thanks, good to hear. > > Can you please add a Cc: stable ? This patch should at least be > backported to 3.15, where uas support has been declared stable. > > With uas it is trivial to trigger the BUG_ON (and break any further > device hotplugging) since uas allows for tcq, and thus using tags > over usb (with all of its hotplug goodness and badness). I did mark it stable when queuing it up, so should be all set. -- Jens Axboe