From 0445f92c5d537c173a54446b80d2052145de5148 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 17 Dec 2018 13:34:59 -0500 Subject: [PATCH] SUNRPC: Fix disconnection races When the socket is closed, we need to call xprt_disconnect_done() in order to clean up the XPRT_WRITE_SPACE flag, and wake up the sleeping tasks. However, we also want to ensure that we don't wake them up before the socket is closed, since that would cause thundering herd issues with everyone piling up to retransmit before the TCP shutdown dance has completed. Only the task that holds XPRT_LOCKED needs to wake up early in order to allow the close to complete. Reported-by: Dave Wysochanski Reported-by: Scott Mayhew Cc: Chuck Lever Signed-off-by: Trond Myklebust Tested-by: Chuck Lever --- net/sunrpc/clnt.c | 1 + net/sunrpc/xprt.c | 5 ++++- net/sunrpc/xprtsock.c | 6 ++---- 3 files changed, 7 insertions(+), 5 deletions(-) diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index c6782aa47525..24cbddc44c88 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -1952,6 +1952,7 @@ call_connect_status(struct rpc_task *task) /* retry with existing socket, after a delay */ rpc_delay(task, 3*HZ); /* fall through */ + case -ENOTCONN: case -EAGAIN: /* Check for timeouts before looping back to call_bind */ case -ETIMEDOUT: diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index ce927002862a..3fb001dff670 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -680,7 +680,9 @@ void xprt_force_disconnect(struct rpc_xprt *xprt) /* Try to schedule an autoclose RPC call */ if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0) queue_work(xprtiod_workqueue, &xprt->task_cleanup); - xprt_wake_pending_tasks(xprt, -EAGAIN); + else if (xprt->snd_task) + rpc_wake_up_queued_task_set_status(&xprt->pending, + xprt->snd_task, -ENOTCONN); spin_unlock_bh(&xprt->transport_lock); } EXPORT_SYMBOL_GPL(xprt_force_disconnect); @@ -852,6 +854,7 @@ static void xprt_connect_status(struct rpc_task *task) case -ENETUNREACH: case -EHOSTUNREACH: case -EPIPE: + case -ENOTCONN: case -EAGAIN: dprintk("RPC: %5u xprt_connect_status: retrying\n", task->tk_pid); break; diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 8a5e823e0b33..4c471b4235ba 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1217,6 +1217,8 @@ static void xs_reset_transport(struct sock_xprt *transport) trace_rpc_socket_close(xprt, sock); sock_release(sock); + + xprt_disconnect_done(xprt); } /** @@ -1237,8 +1239,6 @@ static void xs_close(struct rpc_xprt *xprt) xs_reset_transport(transport); xprt->reestablish_timeout = 0; - - xprt_disconnect_done(xprt); } static void xs_inject_disconnect(struct rpc_xprt *xprt) @@ -1489,8 +1489,6 @@ static void xs_tcp_state_change(struct sock *sk) &transport->sock_state)) xprt_clear_connecting(xprt); clear_bit(XPRT_CLOSING, &xprt->state); - if (sk->sk_err) - xprt_wake_pending_tasks(xprt, -sk->sk_err); /* Trigger the socket release */ xs_tcp_force_close(xprt); }