diff --git a/scst/include/scst.h b/scst/include/scst.h
index adb64540f..ecc4e6361 100644
--- a/scst/include/scst.h
+++ b/scst/include/scst.h
@@ -3104,10 +3104,6 @@ struct scst_tgt_dev {
 	/* List entry in sess->sess_tgt_dev_list */
 	struct list_head sess_tgt_dev_list_entry;
 
-	struct rcu_head rcu;
-	struct work_struct free_work;
-	atomic_t *a;
-
 	struct scst_device *dev; /* to save extra dereferences */
 	uint64_t lun;		 /* to save extra dereferences */
 
@@ -3263,13 +3259,6 @@ struct scst_acg_dev {
 	/* sysfs release completion */
 	struct completion *acg_dev_kobj_release_cmpl;
 
-	/*
-	 * Number of deleted tgt_devs associated with this acg_dev. Set if an
-	 * acg_dev is no longer visible and will be freed as soon as all
-	 * associated tgt_dev instances have been freed.
-	 */
-	int nr_deleted_tgt_devs;
-
 	/* Name of the link to the corresponding LUN */
 	char acg_dev_link_name[20];
 };
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index f5a967440..97322c601 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -4547,8 +4547,11 @@ out_on_del:
 		scst_cm_on_del_lun(acg_dev, false);
 
 out_free:
-	/* To do: verify whether this synchronize_rcu() call is necessary. */
-	synchronize_rcu();
+	/*
+	 * synchronize_rcu() does not have to be called here because the
+	 * tgt_devs that will be freed have never been on any of the
+	 * sess->sess_tgt_dev_list[] lists.
+	 */
 	list_for_each_entry_safe(tgt_dev, tt, &tmp_tgt_dev_list,
 			 extra_tgt_dev_list_entry) {
 		scst_free_tgt_dev(tgt_dev);
@@ -4557,37 +4560,10 @@ out_free:
 	goto out;
 }
 
-static void scst_tgt_dev_free_workfn(struct work_struct *work)
-{
-	struct scst_tgt_dev *tgt_dev = container_of(work, typeof(*tgt_dev),
-						    free_work);
-	struct scst_acg_dev *acg_dev = tgt_dev->acg_dev;
-	struct scst_device *dev = tgt_dev->dev;
-	atomic_t *a = tgt_dev->a;
-
-	mutex_lock(&scst_mutex);
-	scst_free_tgt_dev(tgt_dev);
-	WARN_ON_ONCE(acg_dev->nr_deleted_tgt_devs <= 0);
-	if (--acg_dev->nr_deleted_tgt_devs == 0)
-		scst_free_acg_dev(acg_dev);
-	mutex_unlock(&scst_mutex);
-
-	percpu_ref_put(&dev->refcnt);
-	scst_put(a);
-}
-
-void scst_free_tgt_dev_rcu(struct rcu_head *rcu)
-{
-	struct scst_tgt_dev *tgt_dev = container_of(rcu, typeof(*tgt_dev), rcu);
-
-	tgt_dev->a = scst_get();
-	percpu_ref_get(&tgt_dev->dev->refcnt);
-	WARN_ON_ONCE(!schedule_work(&tgt_dev->free_work));
-}
-
 /* Delete a LUN without generating a unit attention. */
 static struct scst_acg_dev *__scst_acg_del_lun(struct scst_acg *acg,
 					       uint64_t lun,
+					       struct list_head *tgt_dev_list,
 					       bool *report_luns_changed)
 {
 	struct scst_acg_dev *acg_dev = NULL, *a;
@@ -4596,6 +4572,8 @@ static struct scst_acg_dev *__scst_acg_del_lun(struct scst_acg *acg,
 
 	lockdep_assert_held(&scst_mutex);
 
+	INIT_LIST_HEAD(tgt_dev_list);
+
 	list_for_each_entry(a, &acg->acg_dev_list, acg_dev_list_entry) {
 		if (a->lun == lun) {
 			acg_dev = a;
@@ -4608,17 +4586,17 @@ static struct scst_acg_dev *__scst_acg_del_lun(struct scst_acg *acg,
 	*report_luns_changed = scst_cm_on_del_lun(acg_dev,
 						  *report_luns_changed);
 
-	acg_dev->nr_deleted_tgt_devs = 1;
-
 	list_for_each_entry_safe(tgt_dev, tt, &acg_dev->dev->dev_tgt_dev_list,
 			 dev_tgt_dev_list_entry) {
 		if (tgt_dev->acg_dev == acg_dev) {
 			sess = tgt_dev->sess;
 
 			mutex_lock(&sess->tgt_dev_list_mutex);
-			acg_dev->nr_deleted_tgt_devs++;
 			scst_del_tgt_dev(tgt_dev);
 			mutex_unlock(&sess->tgt_dev_list_mutex);
+
+			list_add_tail(&tgt_dev->extra_tgt_dev_list_entry,
+				      tgt_dev_list);
 		}
 	}
 
@@ -4631,17 +4609,37 @@ out:
 	return acg_dev;
 }
 
+static int scst_tgt_devs_cmds(struct list_head *tgt_dev_list)
+{
+	struct scst_tgt_dev *tgt_dev;
+	int res = 0;
+
+	list_for_each_entry(tgt_dev, tgt_dev_list, extra_tgt_dev_list_entry)
+		res += atomic_read(&tgt_dev->tgt_dev_cmd_count);
+
+	return res;
+}
+
+static void scst_wait_for_tgt_devs(struct list_head *tgt_dev_list)
+{
+	while (scst_tgt_devs_cmds(tgt_dev_list) > 0)
+		mdelay(100);
+}
+
 int scst_acg_del_lun(struct scst_acg *acg, uint64_t lun,
 		     bool gen_report_luns_changed)
 {
 	int res = 0;
 	struct scst_acg_dev *acg_dev;
+	struct scst_tgt_dev *tgt_dev, *tt;
+	struct list_head tgt_dev_list;
 
 	TRACE_ENTRY();
 
 	lockdep_assert_held(&scst_mutex);
 
-	acg_dev = __scst_acg_del_lun(acg, lun, &gen_report_luns_changed);
+	acg_dev = __scst_acg_del_lun(acg, lun, &tgt_dev_list,
+				     &gen_report_luns_changed);
 	if (acg_dev == NULL) {
 		PRINT_ERROR("Device is not found in group %s", acg->acg_name);
 		res = -EINVAL;
@@ -4653,11 +4651,16 @@ int scst_acg_del_lun(struct scst_acg *acg, uint64_t lun,
 
 	mutex_unlock(&scst_mutex);
 
+	scst_wait_for_tgt_devs(&tgt_dev_list);
 	synchronize_rcu();
 
 	mutex_lock(&scst_mutex);
-	if (--acg_dev->nr_deleted_tgt_devs == 0)
-		scst_free_acg_dev(acg_dev);
+
+	list_for_each_entry_safe(tgt_dev, tt, &tgt_dev_list,
+				 extra_tgt_dev_list_entry) {
+		scst_free_tgt_dev(tgt_dev);
+	}
+	scst_free_acg_dev(acg_dev);
 
 out:
 	TRACE_EXIT_RES(res);
@@ -4671,12 +4674,13 @@ int scst_acg_repl_lun(struct scst_acg *acg, struct kobject *parent,
 {
 	struct scst_acg_dev *acg_dev;
 	bool del_gen_ua = false;
-	struct scst_tgt_dev *tgt_dev;
+	struct scst_tgt_dev *tgt_dev, *tt;
+	struct list_head tgt_dev_list;
 	int res = -EINVAL;
 
 	lockdep_assert_held(&scst_mutex);
 
-	acg_dev = __scst_acg_del_lun(acg, lun, &del_gen_ua);
+	acg_dev = __scst_acg_del_lun(acg, lun, &tgt_dev_list, &del_gen_ua);
 	if (!acg_dev)
 		flags |= SCST_ADD_LUN_GEN_UA;
 	res = scst_acg_add_lun(acg, parent, dev, lun, flags, NULL);
@@ -4697,10 +4701,15 @@ int scst_acg_repl_lun(struct scst_acg *acg, struct kobject *parent,
 	}
 	mutex_unlock(&scst_mutex);
 
+	scst_wait_for_tgt_devs(&tgt_dev_list);
 	synchronize_rcu();
 
 	mutex_lock(&scst_mutex);
-	if (acg_dev && --acg_dev->nr_deleted_tgt_devs == 0)
+	list_for_each_entry_safe(tgt_dev, tt, &tgt_dev_list,
+				 extra_tgt_dev_list_entry) {
+		scst_free_tgt_dev(tgt_dev);
+	}
+	if (acg_dev)
 		scst_free_acg_dev(acg_dev);
 
 out:
@@ -5283,6 +5292,9 @@ void scst_tgt_dev_stop_threads(struct scst_tgt_dev *tgt_dev)
 
 	lockdep_assert_held(&scst_mutex);
 
+	if (tgt_dev->dev->threads_num < 0)
+		goto out_deinit;
+
 	if (tgt_dev->active_cmd_threads == &scst_main_cmd_threads) {
 		/* Global async threads */
 		kref_put(&tgt_dev->aic_keeper->aic_keeper_kref,
@@ -5299,6 +5311,7 @@ void scst_tgt_dev_stop_threads(struct scst_tgt_dev *tgt_dev)
 		scst_deinit_threads(&tgt_dev->tgt_dev_cmd_threads);
 	} /* else no threads (not yet initialized, e.g.) */
 
+out_deinit:
 	tm_dbg_deinit_tgt_dev(tgt_dev);
 	tgt_dev->active_cmd_threads = NULL;
 
@@ -5336,8 +5349,6 @@ static int scst_alloc_add_tgt_dev(struct scst_session *sess,
 	}
 
 	INIT_LIST_HEAD(&tgt_dev->sess_tgt_dev_list_entry);
-	init_rcu_head(&tgt_dev->rcu);
-	INIT_WORK(&tgt_dev->free_work, scst_tgt_dev_free_workfn);
 	tgt_dev->dev = dev;
 	tgt_dev->lun = acg_dev->lun;
 	tgt_dev->acg_dev = acg_dev;
@@ -5502,8 +5513,6 @@ out_dec_free:
 out_free_ua:
 	scst_free_all_UA(tgt_dev);
 
-	destroy_rcu_head(&tgt_dev->rcu);
-
 	kmem_cache_free(scst_tgtd_cachep, tgt_dev);
 	goto out;
 }
@@ -5547,8 +5556,7 @@ static void scst_del_tgt_dev(struct scst_tgt_dev *tgt_dev)
 
 	scst_tgt_dev_sysfs_del(tgt_dev);
 
-	if (atomic_dec_return(&tgt_dev->tgt_dev_cmd_count) == 0)
-		call_rcu(&tgt_dev->rcu, scst_free_tgt_dev_rcu);
+	atomic_dec(&tgt_dev->tgt_dev_cmd_count);
 }
 
 /*
@@ -5585,8 +5593,6 @@ static void scst_free_tgt_dev(struct scst_tgt_dev *tgt_dev)
 
 	scst_tgt_dev_stop_threads(tgt_dev);
 
-	destroy_rcu_head(&tgt_dev->rcu);
-
 	kmem_cache_free(scst_tgtd_cachep, tgt_dev);
 
 	percpu_ref_put(&dev->refcnt);
diff --git a/scst/src/scst_priv.h b/scst/src/scst_priv.h
index 84788dd89..e0d378e0e 100644
--- a/scst/src/scst_priv.h
+++ b/scst/src/scst_priv.h
@@ -382,7 +382,6 @@ void scst_check_reassign_sessions(void);
 int scst_sess_alloc_tgt_devs(struct scst_session *sess);
 void scst_sess_free_tgt_devs(struct scst_session *sess);
 struct scst_tgt_dev *scst_lookup_tgt_dev(struct scst_session *sess, u64 lun);
-void scst_free_tgt_dev_rcu(struct rcu_head *rcu);
 void scst_nexus_loss(struct scst_tgt_dev *tgt_dev, bool queue_UA);
 
 #define SCST_ADD_LUN_READ_ONLY	1
diff --git a/scst/src/scst_targ.c b/scst/src/scst_targ.c
index a0918ae71..f73605a85 100644
--- a/scst/src/scst_targ.c
+++ b/scst/src/scst_targ.c
@@ -4504,8 +4504,7 @@ static int scst_pre_xmit_response1(struct scst_cmd *cmd)
 		 * latency, so we should decrement them after cmd completed.
 		 */
 		smp_mb__before_atomic_dec();
-		if (atomic_dec_return(&cmd->tgt_dev->tgt_dev_cmd_count) == 0)
-			call_rcu(&cmd->tgt_dev->rcu, scst_free_tgt_dev_rcu);
+		atomic_dec(&cmd->tgt_dev->tgt_dev_cmd_count);
 		percpu_ref_put(&cmd->dev->refcnt);
 #ifdef CONFIG_SCST_PER_DEVICE_CMD_COUNT_LIMIT
 		atomic_dec(&cmd->dev->dev_cmd_count);