drbd: Fixed an issue with AHEAD -> SYNC_SOURCE transitions
Create a new barrier when leaving the AHEAD mode.
Otherwise we trigger the assertion in req_mod(, barrier_acked)
D_ASSERT(req->rq_state & RQ_NET_SENT);
The new barrier is created by recycling the newest existing one.
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_main.c b/drivers/block/drbd/drbd_main.c
index 9bd53cf..90050ab 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -335,6 +335,24 @@
drbd_force_state(mdev, NS(conn, C_PROTOCOL_ERROR));
}
+
+/* In C_AHEAD mode only out_of_sync packets are sent for requests. Detach
+ * those requests from the newsest barrier when changing to an other cstate.
+ *
+ * That headless list vanishes when the last request finished its write or
+ * send out_of_sync packet. */
+static void tl_forget(struct drbd_conf *mdev)
+{
+ struct drbd_tl_epoch *b;
+
+ if (test_bit(CREATE_BARRIER, &mdev->flags))
+ return;
+
+ b = mdev->newest_tle;
+ list_del(&b->requests);
+ _tl_add_barrier(mdev, b);
+}
+
/**
* _tl_restart() - Walks the transfer log, and applies an action to all requests
* @mdev: DRBD device.
@@ -1242,6 +1260,9 @@
if (os.conn < C_CONNECTED && ns.conn >= C_CONNECTED)
drbd_resume_al(mdev);
+ if (os.conn == C_AHEAD && ns.conn != C_AHEAD)
+ tl_forget(mdev);
+
ascw = kmalloc(sizeof(*ascw), GFP_ATOMIC);
if (ascw) {
ascw->os = os;
