From mboxrd@z Thu Jan  1 00:00:00 1970
From: piaojun <piaojun@huawei.com>
Date: Fri, 2 Mar 2018 17:40:54 +0800
Subject: [Ocfs2-devel] [PATCH] ocfs2/dlm: don't handle migrate lockres
 if already in shutdown
In-Reply-To: <20180301152931.f878871c36e9e92e03529685@linux-foundation.org>
References: <5A97C734.5020705@huawei.com>
	<63ADC13FD55D6546B7DECE290D39E373F292B279@H3CMLB12-EX.srv.huawei-3com.com>
	<5A97F41E.5090800@huawei.com>
	<20180301152931.f878871c36e9e92e03529685@linux-foundation.org>
Message-ID: <5A991C26.7050305@huawei.com>
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To: ocfs2-devel@oss.oracle.com

Hi Andrew,

Thanks for your suggestion, I will give a more comprehensive changelog in
patch v2 later.

thanks,
Jun

On 2018/3/2 7:29, Andrew Morton wrote:
> On Thu, 1 Mar 2018 20:37:50 +0800 piaojun <piaojun@huawei.com> wrote:
> 
>> Hi Changwei,
>>
>> Thanks for your quick reply, please see my comments below.
>>
>> On 2018/3/1 17:39, Changwei Ge wrote:
>>> Hi Jun,
>>>
>>> On 2018/3/1 17:27, piaojun wrote:
>>>> We should not handle migrate lockres if we are already in
>>>> 'DLM_CTXT_IN_SHUTDOWN', as that will cause lockres remains after
>>>> leaving dlm domain. At last other nodes will get stuck into infinite
>>>> loop when requsting lock from us.
>>>>
>>>>      N1                             N2 (owner)
>>>>                                     touch file
>>>>
>>>> access the file,
>>>> and get pr lock
>>>>
>>>> umount
>>>>
>>>
>>> Before migrating all lock resources, N1 should have already sent 
>>> DLM_BEGIN_EXIT_DOMAIN_MSG in dlm_begin_exit_domain().
>>> N2 will set ->exit_domain_map later.
>>> So N2 can't take N1 as migration target.
>> Before receiveing N1's DLM_BEGIN_EXIT_DOMAIN_MSG, N2 has picked up N1 as
>> the migrate target. So N2 will continue sending lockres to N1 even though
>> N1 has left domain. Sorry for making you misunderstanding, I will give a
>> more detailed description.
>>
>>     N1                             N2 (owner)
>>                                    touch file
>>
>> access the file,
>> and get pr lock
>>
>>                                    begin leave domain and
>>                                    pick up N1 as new owner
>>
>> begin leave domain and
>> migrate all lockres done
>>
>>                                    begin migrate lockres to N1
>>
>> end leave domain, but
>> the lockres left
>> unexpectedly, because
>> migrate task has passed
> 
> If someone asked a question then this is a sign that the changelog was
> missing details.  So please do send along a v2 with a more
> comprehensive changelog.
> 
> .
>