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drbd: fix disconnect/reconnect loop, if ping-timeout == ping-int

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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>
This commit is contained in:
Lars Ellenberg 2011-03-09 22:44:55 +01:00 committed by Philipp Reisner
parent 53ea433145
commit f36af18c7b
1 changed files with 8 additions and 2 deletions
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10
drivers/block/drbd/drbd_receiver.c
View file

@ -4554,6 +4554,7 @@ int drbd_asender(struct drbd_thread *thi)
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 @@ int drbd_asender(struct drbd_thread *thi)
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 @@ int drbd_asender(struct drbd_thread *thi)
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 @@ int drbd_asender(struct drbd_thread *thi)
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);