diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index 237571af77fdfcf552b7061fa13ff291514c86b7..a680c761341f14caa0702320c9e0dcb53e89fabe 100644
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -614,7 +614,7 @@ static int __commit_transaction(struct dm_pool_metadata *pmd)
 	if (r < 0)
 		goto out;
 
-	r = dm_sm_root_size(pmd->metadata_sm, &data_len);
+	r = dm_sm_root_size(pmd->data_sm, &data_len);
 	if (r < 0)
 		goto out;