fix ldev reference count imbalance on fault injection

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

drivers/block/drbd/drbd_receiver.c

@@ -279,6 +279,9 @@ struct drbd_epoch_entry *drbd_alloc_ee(struct drbd_conf *mdev,
 	struct bio *bio;
 	unsigned int ds;
 
+	if (FAULT_ACTIVE(mdev, DRBD_FAULT_AL_EE))
+		return NULL;
+
 	e = mempool_alloc(drbd_ee_mempool, gfp_mask & ~__GFP_HIGHMEM);
 	if (!e) {
 		if (!(gfp_mask & __GFP_NOWARN))

drivers/block/drbd/drbd_worker.c

@@ -375,9 +375,6 @@ static int read_for_csum(struct drbd_conf *mdev, sector_t sector, int size)
 	if (!get_ldev(mdev))
 		return 0;
 
-	if (FAULT_ACTIVE(mdev, DRBD_FAULT_AL_EE))
-		return 2;
-
 	/* GFP_TRY, because if there is no memory available right now, this may
 	 * be rescheduled for later. It is "only" background resync, after all. */
 	e = drbd_alloc_ee(mdev, DRBD_MAGIC+0xbeef, sector, size, GFP_TRY);