zvol_level.patch

diff --git a/module/zfs/dmu_objset.c b/module/zfs/dmu_objset.c
index 22ca84d..d372ea2 100644
--- a/module/zfs/dmu_objset.c
+++ b/module/zfs/dmu_objset.c
@@ -854,6 +854,9 @@ dmu_objset_create_impl(spa_t *spa, dsl_dataset_t *ds, blkptr_t *bp,
 		    DN_MAX_OBJECT * sizeof (dnode_phys_t))
 			levels++;
 
+		if (type == DMU_OST_ZVOL)
+			levels = 2;
+
 		mdn->dn_next_nlevels[tx->tx_txg & TXG_MASK] =
 		    mdn->dn_nlevels = levels;
 	}