SUNRPC: If the rpcbind channel is disconnected, fail the call to unregister

If rpcbind causes our connection to the AF_LOCAL socket to close after
we've registered a service, then we want to be careful about reconnecting
since the mount namespace may have changed.

By simply refusing to reconnect the AF_LOCAL socket in the case of
unregister, we avoid the need to somehow save the mount namespace. While
this may lead to some services not unregistering properly, it should
be safe.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Nix <nix@esperi.org.uk>
Cc: Jeff Layton <jlayton@redhat.com>
Cc: stable@vger.kernel.org # 3.9.x

1 files changed, 1 insertions, 0 deletions

diff --git a/net/sunrpc/netns.h b/net/sunrpc/netns.h
index 74d948f..779742c 100644
--- a/net/sunrpc/netns.h
+++ b/net/sunrpc/netns.h
@@ -23,6 +23,7 @@ struct sunrpc_net {
 	struct rpc_clnt *rpcb_local_clnt4;
 	spinlock_t rpcb_clnt_lock;
 	unsigned int rpcb_users;
+	unsigned int rpcb_is_af_local : 1;
 
 	struct mutex gssp_lock;
 	wait_queue_head_t gssp_wq;