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: 89f90fe1ad ("SUNRPC: Allow calls to xprt_transmit() to drain...")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
This commit is contained in:
Trond Myklebust 2019-03-04 14:19:31 -05:00
parent 0d1bf3407c
commit ed7dc973bd

View File

@ -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_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;
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;
}
}