SUNRPC: Avoid an unnecessary task reschedule on ENOTCONN
If the socket is unconnected, and xprt_transmit() returns ENOTCONN, we
currently give up the lock on the transport channel. Doing so means that
the lock automatically gets assigned to the next task in the xprt->sending
queue, and so that task needs to be woken up to do the actual connect.
The following patch aims to avoid that unnecessary task switch.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 836f15c..07e9b05 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1105,14 +1105,24 @@
call_transmit_status(struct rpc_task *task)
{
task->tk_action = call_status;
- /*
- * Special case: if we've been waiting on the socket's write_space()
- * callback, then don't call xprt_end_transmit().
- */
- if (task->tk_status == -EAGAIN)
- return;
- xprt_end_transmit(task);
- rpc_task_force_reencode(task);
+ switch (task->tk_status) {
+ case -EAGAIN:
+ break;
+ default:
+ xprt_end_transmit(task);
+ /*
+ * Special cases: if we've been waiting on the
+ * socket's write_space() callback, or if the
+ * socket just returned a connection error,
+ * then hold onto the transport lock.
+ */
+ case -ECONNREFUSED:
+ case -ENOTCONN:
+ case -EHOSTDOWN:
+ case -EHOSTUNREACH:
+ case -ENETUNREACH:
+ rpc_task_force_reencode(task);
+ }
}
/*
