Re: [PATCH RFC] NFS/RDMA Release resources in svcrdma when device is removed

[Shirley Ma <shirley.ma@oracle.com>]

On 06/03/2015 11:49 AM, Chuck Lever wrote:
> 
> On Jun 3, 2015, at 2:44 PM, Chuck Lever <chuck.lever@oracle.com> wrote:
> 
>>
>> On Jun 3, 2015, at 2:40 PM, Shirley Ma <shirley.ma@oracle.com> wrote:
>>
>>> When removing underlying RDMA device, the rmmod will hang forever if there
>>> are any outstanding NFS/RDMA client mounts. The outstanding NFS/RDMA counts 
>>> could also prevent the server from shutting down. Further debugging shows 
>>> that the existing connections are not teared down and resource are not 
>>> released when receiving RDMA_CM_EVENT_DEVICE_REMOVAL event. It seems the 
>>> original code missing svc_xprt_put() in RDMA_CM_EVENT_REMOVAL event handler 
>>> thus svc_xprt_free is never invoked to release the existing connection resources.
>>>
>>> The patch has been passed removing, adding device back and forth without 
>>> stopping NFS/RDMA service. This will also allow a device to be unplugged 
>>> and swapped out without shutting down NFS service.
> 
> And maybe also add:
> 
> BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=252

Yes, this patch has addressed above problem too. I forgot this bug.
 
> here.
> 
>>> Signed-off-by: Shirley Ma <shirley.ma@oracle.com>
>>
>> Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
>>
>>> ---
>>> net/sunrpc/xprtrdma/svc_rdma_transport.c | 1 +
>>> 1 file changed, 1 insertion(+)
>>>
>>> diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
>>> index f609c1c..2b82569 100644
>>> --- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
>>> +++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
>>> @@ -673,6 +673,7 @@ static int rdma_cma_handler(struct rdma_cm_id *cma_id,
>>> 		if (xprt) {
>>> 			set_bit(XPT_CLOSE, &xprt->xpt_flags);
>>> 			svc_xprt_enqueue(xprt);
>>> +			svc_xprt_put(xprt);
>>> 		}
>>> 		break;
>>> 	default:
>>>
>>> Shirley
>>
>> --
>> Chuck Lever
>> chuck[dot]lever[at]oracle[dot]com
>>
>>
>>
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> 
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
> 
> 
>