Commit ed7dc973 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

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: 89f90fe1 ("SUNRPC: Allow calls to xprt_transmit() to drain...")
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent 0d1bf340

net/sunrpc/clnt.c

+17 −4
Original line number Diff line number Diff line
@@ -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;

	}

}

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