--- a/fs/gfs2/quota.c
+++ b/fs/gfs2/quota.c
@@ -106,6 +106,7 @@ static inline void spin_unlock_bucket(unsigned int hash)
 static void gfs2_qd_dealloc(struct rcu_head *rcu)
 {
 	struct gfs2_quota_data *qd = container_of(rcu, struct gfs2_quota_data, qd_rcu);
+	qd->qd_sbd = NULL;
 	kmem_cache_free(gfs2_quotad_cachep, qd);
 }