drbd: fix disconnect/reconnect loop, if ping-timeout == ping-int
If there is no replication traffic within the idle timeout
(ping-int seconds), DRBD will send a P_PING,
and adjust the timeout to ping-timeout.
If there is no P_PING_ACK received within this ping-timeout,
DRBD finally drops the connection, and tries to re-establish it.
To decide which timeout was active, we compared the current timeout
with the ping-timeout, and dropped the connection, if that was the case.
By default, ping-int is 10 seconds, ping-timeout is 500 ms.
Unfortunately, if you configure ping-timeout to be the same as ping-int,
expiry of the idle-timeout had been mistaken for a missing ping ack,
and caused an immediate reconnection attempt.
Fix:
Allow both timeouts to be equal, use a local variable
to store which timeout is active.
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 fd26666..0b17d42 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -4554,6 +4554,7 @@
int received = 0;
int expect = sizeof(struct p_header80);
int empty;
+ int ping_timeout_active = 0;
sprintf(current->comm, "drbd%d_asender", mdev_to_minor(mdev));
@@ -4566,6 +4567,7 @@
ERR_IF(!drbd_send_ping(mdev)) goto reconnect;
mdev->meta.socket->sk->sk_rcvtimeo =
mdev->net_conf->ping_timeo*HZ/10;
+ ping_timeout_active = 1;
}
/* conditionally cork;
@@ -4620,8 +4622,7 @@
dev_err(DEV, "meta connection shut down by peer.\n");
goto reconnect;
} else if (rv == -EAGAIN) {
- if (mdev->meta.socket->sk->sk_rcvtimeo ==
- mdev->net_conf->ping_timeo*HZ/10) {
+ if (ping_timeout_active) {
dev_err(DEV, "PingAck did not arrive in time.\n");
goto reconnect;
}
@@ -4660,6 +4661,11 @@
if (!cmd->process(mdev, h))
goto reconnect;
+ /* the idle_timeout (ping-int)
+ * has been restored in got_PingAck() */
+ if (cmd == get_asender_cmd(P_PING_ACK))
+ ping_timeout_active = 0;
+
buf = h;
received = 0;
expect = sizeof(struct p_header80);
