drbd: Fix the WO=drain implementation for multiple volumes

Wait until IO is drained in all volumes.

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 6675e2c..be8f469 100644 (file)
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1334,6 +1334,22 @@ static void drbd_remove_epoch_entry_interval(struct drbd_conf *mdev,
                wake_up(&mdev->misc_wait);
 }
 
+void conn_wait_active_ee_empty(struct drbd_tconn *tconn)
+{
+       struct drbd_conf *mdev;
+       int vnr;
+
+       rcu_read_lock();
+       idr_for_each_entry(&tconn->volumes, mdev, vnr) {
+               kref_get(&mdev->kref);
+               rcu_read_unlock();
+               drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
+               kref_put(&mdev->kref, &drbd_minor_destroy);
+               rcu_read_lock();
+       }
+       rcu_read_unlock();
+}
+
 static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 {
        struct drbd_conf *mdev;
@@ -1372,7 +1388,7 @@ static int receive_Barrier(struct drbd_tconn *tconn, struct packet_info *pi)
 
        case WO_bdev_flush:
        case WO_drain_io:
-               drbd_wait_ee_list_empty(mdev, &mdev->active_ee);
+               conn_wait_active_ee_empty(tconn);
                drbd_flush(tconn);
 
                if (atomic_read(&tconn->current_epoch->epoch_size)) {