Add mas_for_each_rev() function to iterate maple tree nodes in reverse order. Suggested-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> Signed-off-by: Suren Baghdasaryan <surenb@xxxxxxxxxx> Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> --- include/linux/maple_tree.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h index 61c236850ca8..cbbcd18d4186 100644 --- a/include/linux/maple_tree.h +++ b/include/linux/maple_tree.h @@ -592,6 +592,20 @@ static __always_inline void mas_reset(struct ma_state *mas) #define mas_for_each(__mas, __entry, __max) \ while (((__entry) = mas_find((__mas), (__max))) != NULL) +/** + * mas_for_each_rev() - Iterate over a range of the maple tree in reverse order. + * @__mas: Maple Tree operation state (maple_state) + * @__entry: Entry retrieved from the tree + * @__min: minimum index to retrieve from the tree + * + * When returned, mas->index and mas->last will hold the entire range for the + * entry. + * + * Note: may return the zero entry. + */ +#define mas_for_each_rev(__mas, __entry, __min) \ + while (((__entry) = mas_find_rev((__mas), (__min))) != NULL) + #ifdef CONFIG_DEBUG_MAPLE_TREE enum mt_dump_format { mt_dump_dec, -- 2.47.0.105.g07ac214952-goog