Re: [PATCH 1/2] SUNRPC: Ensure that call_connect times out correctly

[Steve Dickson <SteveD@redhat.com>]

On 03/19/2014 01:29 PM, Trond Myklebust wrote:
> On Wed, 2014-03-19 at 13:10 -0400, Steve Dickson wrote:
>>
>> On 03/19/2014 11:04 AM, Trond Myklebust wrote:
>>> IOW: there is no way to make mount.nfs honour the ‘retry’ and/or ‘bg' 
>>> mount options in any consistent fashion by solely relying on kernel timeouts.
>> I went back and took a look at how bg mounts worked in a number of
>> older kernels f19(3.12) all the way back to RHEL6 kernel (2.6). 
>>
>> I turns out you are right. The bg mounts were not depending on
>> timeouts they were depended on the mount to fail with ECONNREFUSED
>> The very first one, which is the reason the bg mount happen
>> so fast... 
>>
>> Its seems these days ECONNREFUSED are no longer return 
>> as an error codes. They basically are turned into a 
>> timeout... Just curious as to why ECONNREFUSED are 
>> no longer returned?
>>
>> Again, thanks for the cycles!
> 
> If the server is down during the initial rpc client creation, then I’d
> still expect that to fail with ECONNREFUSED due to the rpc_ping() call.
> 
> Does the following patch help?
> 
> 
> 8<------------------------------------------------------------
> From dad628cc357a06cff8ce04300ba5c19bd92e73eb Mon Sep 17 00:00:00 2001
> From: Trond Myklebust <trond.myklebust@primarydata.com>
> Date: Wed, 19 Mar 2014 13:25:43 -0400
> Subject: [PATCH] SUNRPC: Ensure call_status() deals correctly with SOFTCONN
>  tasks
> 
> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
> ---
>  net/sunrpc/clnt.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
> index cea1308a6fda..ef96568902c5 100644
> --- a/net/sunrpc/clnt.c
> +++ b/net/sunrpc/clnt.c
> @@ -2004,6 +2004,10 @@ call_status(struct rpc_task *task)
>  	case -EHOSTDOWN:
>  	case -EHOSTUNREACH:
>  	case -ENETUNREACH:
> +		if (RPC_IS_SOFTCONN(task)) {
> +			rpc_exit(task, status);
> +			break;
> +		}
>  		/*
>  		 * Delay any retries for 3 seconds, then handle as if it
>  		 * were a timeout.
> 
No... but I do thing that patch make sense... 

What's going on is-ECONNREFUSED is being seen in call_connect_status() 
and the task is not a soft connection. So call_timeout() is call which 
eventual times out the mount... 

So just for fun I make the SETCLIENTID rpc soft, but for some
reason that didn't work either... I thought for sure it would... 

steved.