Re: [PATCH 03/11] drbd_transport_rdma: put kref for cm in dtr_path_established in error path

[Dongsheng Yang <dongsheng.yang@easystack.cn>]

在 2024/6/28 星期五 下午 5:40, Philipp Reisner 写道:
> Hello Dongsheng,
> 
> Please add more information why you think this change fixes a bug.
> Have you experienced a leak of cm structs?
> We got a RDMA_CM_EVENT_ESTABLISHED event. Even if DRBD does not do
> anything with this cm, we sill expect a RDMA_CM_EVENT_DISCONNECTED in
> the future. Is a problem in the handling of the disconnect?

If dtr_path_established() go into this branch, it will not 
schedule_work(&cm->establish_work);

That means path->cm->state = DSM_CONNECTED; will not be done in 
dtr_path_established_work_fn(), so __dtr_disconnect_path() will not call 
rdma_disconnect(). That means this reference will never be put.
> 
> best regards,
>   Philipp
> 
> On Mon, Jun 24, 2024 at 9:28 AM zhengbing.huang
> <zhengbing.huang@easystack.cn> wrote:
>>
>> From: Dongsheng Yang <dongsheng.yang@easystack.cn>
>>
>> Signed-off-by: Dongsheng Yang <dongsheng.yang@easystack.cn>
>> ---
>>   drbd/drbd_transport_rdma.c | 1 +
>>   1 file changed, 1 insertion(+)
>>
>> diff --git a/drbd/drbd_transport_rdma.c b/drbd/drbd_transport_rdma.c
>> index cfbae0e78..eccd0c6ce 100644
>> --- a/drbd/drbd_transport_rdma.c
>> +++ b/drbd/drbd_transport_rdma.c
>> @@ -922,6 +922,7 @@ static void dtr_path_established(struct dtr_cm *cm)
>>                          atomic_set(&cs->active_state, PCS_INACTIVE);
>>                          wake_up(&cs->wq);
>>                  }
>> +               kref_put(&cm->kref, dtr_destroy_cm);
>>                  return;
>>          }
>>
>> --
>> 2.27.0
>>