drbd: when receive times out on meta socket, also check last receive time on data...

If we have an asymetrically congested network, we may send P_PING,
but due to congestion, the corresponding P_PING_ACK would time out,
and we would drop a (congested, but otherwise) healthy connection
("PingAck did not arrive in time.")

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 25d32c5..43beaca 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4602,6 +4602,11 @@ int drbd_asender(struct drbd_thread *thi)
                        dev_err(DEV, "meta connection shut down by peer.\n");
                        goto reconnect;
                } else if (rv == -EAGAIN) {
+                       /* If the data socket received something meanwhile,
+                        * that is good enough: peer is still alive. */
+                       if (time_after(mdev->last_received,
+                               jiffies - mdev->meta.socket->sk->sk_rcvtimeo))
+                               continue;
                        if (ping_timeout_active) {
                                dev_err(DEV, "PingAck did not arrive in time.\n");
                                goto reconnect;
@@ -4637,6 +4642,7 @@ int drbd_asender(struct drbd_thread *thi)
                                goto reconnect;
                }
                if (received == expect) {
+                       mdev->last_received = jiffies;
                        D_ASSERT(cmd != NULL);
                        if (!cmd->process(mdev, h))
                                goto reconnect;