Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1755972AbaDGSb2 (ORCPT <rfc822;w@1wt.eu>);
	Mon, 7 Apr 2014 14:31:28 -0400
Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:36561 "EHLO
	mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK)
	by vger.kernel.org with ESMTP id S1755642AbaDGSbY convert rfc822-to-8bit
	(ORCPT <rfc822;linux-kernel@vger.kernel.org>);
	Mon, 7 Apr 2014 14:31:24 -0400
From: Josef Bacik <jbacik@fb.com>
To: Sasha Levin <sasha.levin@oracle.com>
CC: Chris Mason <clm@fb.com>, David Sterba <dsterba@suse.cz>,
        Jeff Mahoney <jeffm@suse.com>,
        "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: btrfs: lock inversion between delayed_node->mutex and
 found->groups_sem
Thread-Topic: btrfs: lock inversion between delayed_node->mutex and
 found->groups_sem
Thread-Index: AQHPP+M+3IXI59FKkUuYu2lRKTj7bZrluMoAgA5m3ICADmvngIAEbjGAgAAGQoCAAAzngP//kfJ2
Date: Mon, 7 Apr 2014 18:29:29 +0000
Message-ID: <j7epmjmklw5vs88lxuqjqorq.1396895366402@email.android.com>
References: <53239AE0.8030306@oracle.com>
 <20140317130546.GE29256@twin.jikos.cz> <533307ED.8030700@suse.com>
 <533F20EB.2040500@oracle.com> <20140407165449.GA29256@twin.jikos.cz>
 <5342DD99.3010502@fb.com>,<5342E86B.4000305@oracle.com>
In-Reply-To: <5342E86B.4000305@oracle.com>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: 
X-MS-TNEF-Correlator: 
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7BIT
MIME-Version: 1.0
X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.11.96,1.0.14,0.0.0000
 definitions=2014-04-07_02:2014-04-07,2014-04-07,1970-01-01 signatures=0
X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0
 kscore.is_bulkscore=1.24010135493791e-10 kscore.compositescore=0
 circleOfTrustscore=9.18185114672389 compositescore=0.998981209195878
 urlsuspect_oldscore=0.998981209195878 suspectscore=0
 recipient_domain_to_sender_totalscore=0 phishscore=0 bulkscore=0
 kscore.is_spamscore=0 recipient_to_sender_totalscore=0
 recipient_domain_to_sender_domain_totalscore=64355
 rbsscore=0.998981209195878 spamscore=0
 recipient_to_sender_domain_totalscore=0 urlsuspectscore=0.9 adultscore=0
 classifier=spam adjust=0 reason=mlx scancount=1 engine=7.0.1-1402240000
 definitions=main-1404070162
X-FB-Internal: deliver
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

I was on vacation last week, I'll update btrfs-next today once we are happy with integration.  Thanks,

Josef

Sasha Levin <sasha.levin@oracle.com> wrote:


On 04/07/2014 01:17 PM, Chris Mason wrote:
>
>
> On 04/07/2014 12:54 PM, David Sterba wrote:
>> On Fri, Apr 04, 2014 at 05:15:23PM -0400, Sasha Levin wrote:
>>> On 03/26/2014 01:01 PM, Jeff Mahoney wrote:
>>>> On 3/17/14, 9:05 AM, David Sterba wrote:
>>>>>> On Fri, Mar 14, 2014 at 08:12:16PM -0400, Sasha Levin wrote:
>>>>>>>> While fuzzing with trinity inside a KVM tools guest running the latest -next kernel I've stumbled on the following:
>>>>>>>>
>>>>>>>> [  788.458756]        CPU0                    CPU1 [  788.459188] ----                    ---- [  788.459625] lock(&found->groups_sem); [  788.460041] local_irq_disable(); [  788.460041] lock(&delayed_node->mutex); [  788.460041] lock(&found->groups_sem); [  788.460041]   <Interrupt> [ 788.460041]     lock(&delayed_node->mutex); [  788.460041] [ 788.460041]  *** DEADLOCK *** [  788.460041] [  788.460041] 2 locks held by kswapd3/4199:
>>>>>>
>>>>>> I've once (3.14-rc5) seen the same warning also caused by xfstests/generic/224
>>>> I think this is from my sysfs patches. We call kobject_add while holding the group_sem. kobject_add ultimately allocates with GFP_KERNEL, so it can enter reclaim. This particular case isn't dangerous, but it could hit while hot-adding a device. The fix should be pretty simple.
>>>
>>> Is that fix available anywhere? I'm still seeing the issue in -next.
>>
>> It is: https://urldefense.proofpoint.com/v1/url?u=https://patchwork.kernel.org/patch/3894781/&k=ZVNjlDMF0FElm4dQtryO4A%3D%3D%0A&r=6%2FL0lzzDhu0Y1hL9xm%2BQyA%3D%3D%0A&m=HQJVSK4wPTft1zWwI1cGvwj5OfdmN5UItVlucU1K31o%3D%0A&s=5113699a2e7345a779333c87dd5b1d88b4410a7c7fcd5fa424baeb838ad7d31b , will probably hit -rc2
>>
>
> Its in the integration branch now along with some other important fixes.  We'll get it out shortly

Chris,

Can I suggest adding the integration branch to linux-next as well? That way
all the folks who report issues coming out of -next would be able to test
the fixes as well.


Thanks,
Sasha

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/