SUNRPC: Prevent thundering herd when the socket is not connected
If the socket is not connected, then we want to initiate a reconnect
rather that trying to transmit requests. If there is a large number
of requests queued and waiting for the lock in call_transmit(),
then it can take a while for one of the to loop back and retake
the lock in call_connect.
Fixes: 89f90fe1ad8b ("SUNRPC: Allow calls to xprt_transmit() to drain...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 241e842..7ab4da3 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1807,7 +1807,12 @@ call_encode(struct rpc_task *task)
xprt_request_enqueue_receive(task);
xprt_request_enqueue_transmit(task);
out:
- task->tk_action = call_bind;
+ task->tk_action = call_transmit;
+ /* Check that the connection is OK */
+ if (!xprt_bound(task->tk_xprt))
+ task->tk_action = call_bind;
+ else if (!xprt_connected(task->tk_xprt))
+ task->tk_action = call_connect;
}
/*
@@ -1999,13 +2004,19 @@ call_transmit(struct rpc_task *task)
{
dprint_status(task);
- task->tk_status = 0;
+ task->tk_action = call_transmit_status;
if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
if (!xprt_prepare_transmit(task))
return;
- xprt_transmit(task);
+ task->tk_status = 0;
+ if (test_bit(RPC_TASK_NEED_XMIT, &task->tk_runstate)) {
+ if (!xprt_connected(task->tk_xprt)) {
+ task->tk_status = -ENOTCONN;
+ return;
+ }
+ xprt_transmit(task);
+ }
}
- task->tk_action = call_transmit_status;
xprt_end_transmit(task);
}
@@ -2067,6 +2078,8 @@ call_transmit_status(struct rpc_task *task)
case -EADDRINUSE:
case -ENOTCONN:
case -EPIPE:
+ task->tk_action = call_bind;
+ task->tk_status = 0;
break;
}
}
