From 8593e010786181df887b001824ff8f3e52e2098f Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Fri, 13 Sep 2019 16:01:07 -0400 Subject: [PATCH] SUNRPC: Fix congestion window race with disconnect If the congestion window closes just as the transport disconnects, a reconnect is never driven because: 1. The XPRT_CONG_WAIT flag prevents tasks from taking the write lock 2. There's no wake-up of the first task on the xprt->sending queue To address this, clear the congestion wait flag as part of completing a disconnect. Fixes: 75891f502f5f ("SUNRPC: Support for congestion control ... ") Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprt.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c index 02d5b2125c07..83ec4edd2f91 100644 --- a/net/sunrpc/xprt.c +++ b/net/sunrpc/xprt.c @@ -456,6 +456,12 @@ void xprt_release_rqst_cong(struct rpc_task *task) } EXPORT_SYMBOL_GPL(xprt_release_rqst_cong); +static void xprt_clear_congestion_window_wait_locked(struct rpc_xprt *xprt) +{ + if (test_and_clear_bit(XPRT_CWND_WAIT, &xprt->state)) + __xprt_lock_write_next_cong(xprt); +} + /* * Clear the congestion window wait flag and wake up the next * entry on xprt->sending @@ -671,6 +677,7 @@ void xprt_disconnect_done(struct rpc_xprt *xprt) spin_lock(&xprt->transport_lock); xprt_clear_connected(xprt); xprt_clear_write_space_locked(xprt); + xprt_clear_congestion_window_wait_locked(xprt); xprt_wake_pending_tasks(xprt, -ENOTCONN); spin_unlock(&xprt->transport_lock); }