KJ: md-table use list_for_each

index 8939e61..1a735bb 100644
@@ -280,9 +280,8 @@ static void free_devices(struct list_head *devices)
 {
 	struct list_head *tmp, *next;
 
-	for (tmp = devices->next; tmp != devices; tmp = next) {
+	list_for_each_safe(tmp, next, devices) {	
 		struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-		next = tmp->next;
 		kfree(dd);
 	}
 }

@@ -972,12 +971,11 @@ int dm_table_resume_targets(struct dm_table *t)
 
 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 {
-	struct list_head *d, *devices;
+	struct dm_dev *dd;
+	struct list_head *devices = dm_table_get_devices(t);
 	int r = 0;
 
-	devices = dm_table_get_devices(t);
-	for (d = devices->next; d != devices; d = d->next) {
-		struct dm_dev *dd = list_entry(d, struct dm_dev, list);
+	list_for_each_entry(dd, devices, list) {
 		struct request_queue *q = bdev_get_queue(dd->bdev);
 		r |= bdi_congested(&q->backing_dev_info, bdi_bits);
 	}

@@ -987,10 +985,10 @@ int dm_table_any_congested(struct dm_table *t, int bdi_bits)
 
 void dm_table_unplug_all(struct dm_table *t)
 {
+	struct dm_dev *dd;
 	struct list_head *d, *devices = dm_table_get_devices(t);
 
-	for (d = devices->next; d != devices; d = d->next) {
-		struct dm_dev *dd = list_entry(d, struct dm_dev, list);
+	list_for_each_entry(dd, devices, list) {
 		struct request_queue *q = bdev_get_queue(dd->bdev);
 
 		if (q->unplug_fn)