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: Peng Zhang <zhangpeng.00@bytedance.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Peng Zhang 2023-05-24 11:12:44 +08:00 committed by Andrew Morton
parent c6fc9e4a5c
commit 2e1da329b4
1 changed files with 24 additions and 25 deletions

View File

@ -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)
ma_set_meta(wr_mas->node, maple_leaf_64, 0, new_end);
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 (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->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->last == wr_mas->r_max) {
/* Append to end of range */
rcu_assign_pointer(wr_mas->slots[new_end], wr_mas->entry);
wr_mas->pivots[end] = mas->index - 1;
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;