[Devel] Re: [PATCH 2/3] SUNRPC: check rpcbind clients usage counter before decrement

[J. Bruce Fields]

On Wed, Apr 25, 2012 at 05:37:49PM +0400, Stanislav Kinsbursky wrote:
> Registering service with svc_bind() can fail. In this case service will be
> destroyed and during destruction it will try to unregister itself from rpcbind.
> In this case unregister have to be skipped.

Isn't this a preexisting bug, in which case perhaps Trond should at it
to his list of bugs to submit now?

--b.

> 
> Signed-off-by: Stanislav Kinsbursky <skinsbursky at parallels.com>
> 
> ---
>  net/sunrpc/rpcb_clnt.c |   12 +++++++-----
>  1 files changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
> index 78ac39f..4c38b33 100644
> --- a/net/sunrpc/rpcb_clnt.c
> +++ b/net/sunrpc/rpcb_clnt.c
> @@ -180,14 +180,16 @@ void rpcb_put_local(struct net *net)
>  	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
>  	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
>  	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
> -	int shutdown;
> +	int shutdown = 0;
>  
>  	spin_lock(&sn->rpcb_clnt_lock);
> -	if (--sn->rpcb_users == 0) {
> -		sn->rpcb_local_clnt = NULL;
> -		sn->rpcb_local_clnt4 = NULL;
> +	if (sn->rpcb_users) {
> +		if (--sn->rpcb_users == 0) {
> +			sn->rpcb_local_clnt = NULL;
> +			sn->rpcb_local_clnt4 = NULL;
> +		}
> +		shutdown = !sn->rpcb_users;
>  	}
> -	shutdown = !sn->rpcb_users;
>  	spin_unlock(&sn->rpcb_clnt_lock);
>  
>  	if (shutdown) {
>