Re: [Ocfs2-devel] [PATCH] ocfs2: give an obvious tip for dismatch cluster names

[Joseph Qi]

Hi Gang,

As you described, only fsdlm will return this error and fsdlm has
already print the same message. So why should we add it outside again?

Thanks,
Joseph

On 17/5/18 18:43, Gang He wrote:
> Hi Joseph,
> 
> 
>>>>
>> Hi Gang,
>>
>> How can we confirm EBADR is only because cluster name mismatch?
>> Since the cluster stack may be o2cb(o2dlm) or user(fsdlm).
> I looked through all the code of OCFS2 (include o2cb), there is not any place which returns this error.
> In fact, the function calling patch ocfs2_fill_super -> ocfs2_mount_volume -> ocfs2_dlm_init -> dlm_new_lockspace
> is very specific path, we can use this errorno to give the uses a more clear tip, 
> since this case looks like a little common during cluster migration, but the customer can quickly
> get the failure cause if there is a error printing.
> Also, I think there is not possible to add this errorno in o2cb path during ocfs2_dlm_init, since o2cb code has been stable for 
> a long time.   
> 
> Thanks
> Gang
> 
>>
>> Thanks,
>> Joseph
>>
>> On 17/5/18 14:35, Gang He wrote:
>>> This patch is used to add an obvious error message, due to
>>> dismatch cluster names between on-disk and in the current cluster.
>>> We can meet this case during OCFS2 cluster migration, if we can
>>> give the user an obvious tip for why they can not mount the file
>>> system after migration, they can quickly fix this dismatch problem.
>>> Second, also move printing ocfs2_fill_super() errno to the front
>>> of ocfs2_dismount_volume() function, since ocfs2_dismount_volume()
>>> will also print it's own message.
>>>
>>> Signed-off-by: Gang He <ghe@xxxxxxxx>
>>> ---
>>>  fs/ocfs2/super.c | 8 ++++++--
>>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
>>> index ca1646f..5575918 100644
>>> --- a/fs/ocfs2/super.c
>>> +++ b/fs/ocfs2/super.c
>>> @@ -1208,14 +1208,15 @@ static int ocfs2_fill_super(struct super_block *sb, 
>> void *data, int silent)
>>>  read_super_error:
>>>  	brelse(bh);
>>>  
>>> +	if (status)
>>> +		mlog_errno(status);
>>> +
>>>  	if (osb) {
>>>  		atomic_set(&osb->vol_state, VOLUME_DISABLED);
>>>  		wake_up(&osb->osb_mount_event);
>>>  		ocfs2_dismount_volume(sb, 1);
>>>  	}
>>>  
>>> -	if (status)
>>> -		mlog_errno(status);
>>>  	return status;
>>>  }
>>>  
>>> @@ -1843,6 +1844,9 @@ static int ocfs2_mount_volume(struct super_block *sb)
>>>  	status = ocfs2_dlm_init(osb);
>>>  	if (status < 0) {
>>>  		mlog_errno(status);
>>> +		if (status == -EBADR)
>>> +			mlog(ML_ERROR, "couldn't mount because cluster name on"
>>> +			" disk does not match the running cluster name.\n");
>>>  		goto leave;
>>>  	}
>>>  
>>>
>