Re: [PATCH net 1/3] net/smc: Resolve the race between link group access and termination

[Wen Gu <guwen@linux.alibaba.com>]

On 2022/1/10 8:25 pm, Karsten Graul wrote:
> On 10/01/2022 10:26, Wen Gu wrote:
>> We encountered some crashes caused by the race between the access
>> and the termination of link groups.
>>

>> @@ -1120,8 +1122,22 @@ void smc_conn_free(struct smc_connection *conn)
>>   {
>>   	struct smc_link_group *lgr = conn->lgr;
>>   
>> -	if (!lgr)
>> +	if (!lgr || conn->freed)
>> +		/* The connection has never been registered in a
>> +		 * link group, or has already been freed.
>> +		 *
>> +		 * Check to ensure that the refcnt of link group
>> +		 * won't be put incorrectly.
> 
> I would delete the second sentence here, its obvious enough.
> 
>> +		 */
>>   		return;
>> +
>> +	conn->freed = 1;
>> +	if (!conn->alert_token_local)
>> +		/* The connection was registered in a link group
>> +		 * defore, but now it is unregistered from it.
> 
> 'before' ... But would maybe the following be more exact:
> 
> 'Connection already unregistered from link group.'
> 
> 
> We still review the patches...
> 

Thanks for your detailed and patient review. The comments will
be improved as you suggested.

Thanks,
Wen Gu