Revert "maple_tree: disable mas_wr_append() when other readers are po…

…ssible"

This reverts commit cfeb6ae.

lib/maple_tree.c

@@ -4265,10 +4265,6 @@ static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas)
  * mas_wr_append: Attempt to append
  * @wr_mas: the maple write state
  *
- * This is currently unsafe in rcu mode since the end of the node may be cached
- * by readers while the node contents may be updated which could result in
- * inaccurate information.
- *
  * Return: True if appended, false otherwise
  */
 static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
@@ -4278,9 +4274,6 @@ static inline bool mas_wr_append(struct ma_wr_state *wr_mas)
 	struct ma_state *mas = wr_mas->mas;
 	unsigned char node_pivots = mt_pivots[wr_mas->type];
 
-	if (mt_in_rcu(mas->tree))
-		return false;
-
 	if (mas->offset != wr_mas->node_end)
 		return false;