drbd: Implemented two new connection states Ahead/Behind

In this connection mode, the ahead node no longer replicates
application IO. The behind's disk becomes out dated.

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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index f3052d871d31..b19e8b2c4ce5 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -3179,6 +3179,9 @@ static int receive_state(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
         if (ns.conn == C_WF_REPORT_PARAMS)
                 ns.conn = C_CONNECTED;
 
+        if (peer_state.conn == C_AHEAD)
+                ns.conn = C_BEHIND;
+
         if (mdev->p_uuid && peer_state.disk >= D_NEGOTIATING &&
             get_ldev_if_state(mdev, D_NEGOTIATING)) {
                 int cr; /* consider resync */