SUNRPC: Retry bad rpcbind replies

When a server returns a bad rpcbind reply, make rpcbind client recovery logic
retry with an older protocol version.  Older versions are more likely to work
correctly.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

diff --git a/net/sunrpc/rpcb_clnt.c b/net/sunrpc/rpcb_clnt.c
index 34738c5cf31280276b9223cd0a63f7c100481416..a0c9f6905517bb957d69a945e0de4950efa2247f 100644 (file)
--- a/net/sunrpc/rpcb_clnt.c
+++ b/net/sunrpc/rpcb_clnt.c
@@ -446,6 +446,10 @@ static void rpcb_getport_done(struct rpc_task *child, void *data)
        struct rpc_xprt *xprt = map->r_xprt;
        int status = child->tk_status;
 
+       /* Garbage reply: retry with a lesser rpcbind version */
+       if (status == -EIO)
+               status = -EPROTONOSUPPORT;
+
        /* rpcbind server doesn't support this rpcbind protocol version */
        if (status == -EPROTONOSUPPORT)
                xprt->bind_index++;