drbd: Do not segfault if a sync dependency reaches a diskless device

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_worker.c b/drivers/block/drbd/drbd_worker.c
index cbbc5c7..c3d1f5f 100644 (file)
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1319,6 +1319,8 @@ static int _drbd_may_sync_now(struct drbd_conf *mdev)
        struct drbd_conf *odev = mdev;
 
        while (1) {
+               if (!odev->ldev)
+                       return 1;
                if (odev->ldev->dc.resync_after == -1)
                        return 1;
                odev = minor_to_mdev(odev->ldev->dc.resync_after);