diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 4dd73cf936a6..f723024e1426 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -4265,6 +4265,10 @@ 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) @@ -4274,6 +4278,9 @@ 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;