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

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>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 25d32c5aa50a..43beaca53179 100644
--- 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;