Commit 2e1da329 authored by Peng Zhang's avatar Peng Zhang Committed by Andrew Morton
Browse files

maple_tree: add comments and some minor cleanups to mas_wr_append() 

Add comment for mas_wr_append(), move mas_update_gap() into
mas_wr_append(), and other cleanups to make mas_wr_modify() cleaner.

Link: https://lkml.kernel.org/r/20230524031247.65949-8-zhangpeng.00@bytedance.com


Signed-off-by: default avatarPeng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: default avatarLiam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent c6fc9e4a

lib/maple_tree.c

+23 −24
Original line number Diff line number Diff line
@@ -4311,6 +4311,12 @@ static inline unsigned char mas_wr_new_end(struct ma_wr_state *wr_mas) 
	return new_end;

}



/*

 * mas_wr_append: Attempt to append

 * @wr_mas: the maple write state

 *

 * Return: True if appended, false otherwise

 */

static inline bool mas_wr_append(struct ma_wr_state *wr_mas)

{

	unsigned char end = wr_mas->node_end;
@@ -4318,34 +4324,30 @@ 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 ((mas->index != wr_mas->r_min) && (mas->last == wr_mas->r_max)) {

		if (new_end < node_pivots)

			wr_mas->pivots[new_end] = wr_mas->pivots[end];

	if (mas->offset != wr_mas->node_end)

		return false;



		if (new_end < node_pivots)

	if (new_end < node_pivots) {

		wr_mas->pivots[new_end] = wr_mas->pivots[end];

		ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);

	}



	if (mas->last == wr_mas->r_max) {

		/* Append to end of range */

		rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry);

		mas->offset = new_end;

		wr_mas->pivots[end] = mas->index - 1;



		return true;

	}



	if ((mas->index == wr_mas->r_min) && (mas->last < wr_mas->r_max)) {

		if (new_end < node_pivots)

			wr_mas->pivots[new_end] = wr_mas->pivots[end];



		mas->offset = new_end;

	} else {

		/* Append to start of range */

		rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->content);

		if (new_end < node_pivots)

			ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);



		wr_mas->pivots[end] = mas->last;

		rcu_assign_pointer(wr_mas->slots[end], wr_mas->entry);

		return true;

	}



	return false;

	if (!wr_mas->content || !wr_mas->entry)

		mas_update_gap(mas);



	return  true;

}



/*
@@ -4385,12 +4387,9 @@ static inline void mas_wr_modify(struct ma_wr_state *wr_mas) 
	if (new_end >= mt_slots[wr_mas->type])

		goto slow_path;



	if (wr_mas->entry && (wr_mas->node_end < mt_slots[wr_mas->type] - 1) &&

	    (mas->offset == wr_mas->node_end) && mas_wr_append(wr_mas)) {

		if (!wr_mas->content || !wr_mas->entry)

			mas_update_gap(mas);

	/* Attempt to append */

	if (new_end == wr_mas->node_end + 1 && mas_wr_append(wr_mas))

		return;

	}



	if ((wr_mas->offset_end - mas->offset <= 1) && mas_wr_slot_store(wr_mas))

		return;