The patch titled
Subject: maple_tree: simplify and clean up mas_wr_node_store()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-simplify-and-clean-up-mas_wr_node_store.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/maple_tree-simplify-and-clean-up-mas_wr_node_store.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Subject: maple_tree: simplify and clean up mas_wr_node_store()
Date: Wed, 24 May 2023 11:12:46 +0800
Simplify and clean up mas_wr_node_store(), remove unnecessary code.
Link: https://lkml.kernel.org/r/20230524031247.65949-10-zhangpeng.00@xxxxxxxxxxxxx
Signed-off-by: Peng Zhang <zhangpeng.00@xxxxxxxxxxxxx>
Reviewed-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/maple_tree.c | 87 +++++++++++++--------------------------------
1 file changed, 26 insertions(+), 61 deletions(-)
--- a/lib/maple_tree.c~maple_tree-simplify-and-clean-up-mas_wr_node_store
+++ a/lib/maple_tree.c
@@ -4074,52 +4074,27 @@ static inline int mas_wr_spanning_store(
*
* Return: True if stored, false otherwise
*/
-static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas)
+static inline bool mas_wr_node_store(struct ma_wr_state *wr_mas,
+ unsigned char new_end)
{
struct ma_state *mas = wr_mas->mas;
void __rcu **dst_slots;
unsigned long *dst_pivots;
- unsigned char dst_offset;
- unsigned char new_end = wr_mas->node_end;
- unsigned char offset;
- unsigned char node_slots = mt_slots[wr_mas->type];
+ unsigned char dst_offset, offset_end = wr_mas->offset_end;
struct maple_node reuse, *newnode;
- unsigned char copy_size, max_piv = mt_pivots[wr_mas->type];
+ unsigned char copy_size, node_pivots = mt_pivots[wr_mas->type];
bool in_rcu = mt_in_rcu(mas->tree);
- offset = mas->offset;
- if (mas->last == wr_mas->r_max) {
- /* runs right to the end of the node */
- if (mas->last == mas->max)
- new_end = offset;
- /* don't copy this offset */
- wr_mas->offset_end++;
- } else if (mas->last < wr_mas->r_max) {
- /* new range ends in this range */
- if (unlikely(wr_mas->r_max == ULONG_MAX))
- mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);
-
- new_end++;
- } else {
- if (wr_mas->end_piv == mas->last)
- wr_mas->offset_end++;
-
- new_end -= wr_mas->offset_end - offset - 1;
- }
-
- /* new range starts within a range */
- if (wr_mas->r_min < mas->index)
- new_end++;
-
- /* Not enough room */
- if (new_end >= node_slots)
- return false;
-
- /* Not enough data. */
+ /* Check if there is enough data. The room is enough. */
if (!mte_is_root(mas->node) && (new_end <= mt_min_slots[wr_mas->type]) &&
!(mas->mas_flags & MA_STATE_BULK))
return false;
+ if (mas->last == wr_mas->end_piv)
+ offset_end++; /* don't copy this offset */
+ else if (unlikely(wr_mas->r_max == ULONG_MAX))
+ mas_bulk_rebalance(mas, wr_mas->node_end, wr_mas->type);
+
/* set up node. */
if (in_rcu) {
mas_node_count(mas, 1);
@@ -4136,47 +4111,36 @@ static inline bool mas_wr_node_store(str
dst_pivots = ma_pivots(newnode, wr_mas->type);
dst_slots = ma_slots(newnode, wr_mas->type);
/* Copy from start to insert point */
- memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * (offset + 1));
- memcpy(dst_slots, wr_mas->slots, sizeof(void *) * (offset + 1));
- dst_offset = offset;
+ memcpy(dst_pivots, wr_mas->pivots, sizeof(unsigned long) * mas->offset);
+ memcpy(dst_slots, wr_mas->slots, sizeof(void *) * mas->offset);
/* Handle insert of new range starting after old range */
if (wr_mas->r_min < mas->index) {
- mas->offset++;
- rcu_assign_pointer(dst_slots[dst_offset], wr_mas->content);
- dst_pivots[dst_offset++] = mas->index - 1;
+ rcu_assign_pointer(dst_slots[mas->offset], wr_mas->content);
+ dst_pivots[mas->offset++] = mas->index - 1;
}
/* Store the new entry and range end. */
- if (dst_offset < max_piv)
- dst_pivots[dst_offset] = mas->last;
- mas->offset = dst_offset;
- rcu_assign_pointer(dst_slots[dst_offset], wr_mas->entry);
+ if (mas->offset < node_pivots)
+ dst_pivots[mas->offset] = mas->last;
+ rcu_assign_pointer(dst_slots[mas->offset], wr_mas->entry);
/*
* this range wrote to the end of the node or it overwrote the rest of
* the data
*/
- if (wr_mas->offset_end > wr_mas->node_end || mas->last >= mas->max) {
- new_end = dst_offset;
+ if (offset_end > wr_mas->node_end)
goto done;
- }
- dst_offset++;
+ dst_offset = mas->offset + 1;
/* Copy to the end of node if necessary. */
- copy_size = wr_mas->node_end - wr_mas->offset_end + 1;
- memcpy(dst_slots + dst_offset, wr_mas->slots + wr_mas->offset_end,
+ copy_size = wr_mas->node_end - offset_end + 1;
+ memcpy(dst_slots + dst_offset, wr_mas->slots + offset_end,
sizeof(void *) * copy_size);
- if (dst_offset < max_piv) {
- if (copy_size > max_piv - dst_offset)
- copy_size = max_piv - dst_offset;
-
- memcpy(dst_pivots + dst_offset,
- wr_mas->pivots + wr_mas->offset_end,
- sizeof(unsigned long) * copy_size);
- }
+ memcpy(dst_pivots + dst_offset, wr_mas->pivots + offset_end,
+ sizeof(unsigned long) * (copy_size - 1));
- if ((wr_mas->node_end == node_slots - 1) && (new_end < node_slots - 1))
+ if (new_end < node_pivots)
dst_pivots[new_end] = mas->max;
done:
@@ -4378,7 +4342,8 @@ static inline void mas_wr_modify(struct
if (new_end == wr_mas->node_end && mas_wr_slot_store(wr_mas))
return;
- else if (mas_wr_node_store(wr_mas))
+
+ if (mas_wr_node_store(wr_mas, new_end))
return;
if (mas_is_err(mas))
_
Patches currently in -mm which might be from zhangpeng.00@xxxxxxxxxxxxx are
radix-tree-move-declarations-to-header-fix.patch
maple_tree-fix-potential-out-of-bounds-access-in-mas_wr_end_piv.patch
maple_tree-rework-mtree_alloc_rangerrange.patch
maple_tree-drop-mas_rev_alloc-and-mas_fill_gap.patch
maple_tree-fix-the-arguments-to-__must_hold.patch
maple_tree-simplify-mas_is_span_wr.patch
maple_tree-make-the-code-symmetrical-in-mas_wr_extend_null.patch
maple_tree-add-mas_wr_new_end-to-calculate-new_end-accurately.patch
maple_tree-add-comments-and-some-minor-cleanups-to-mas_wr_append.patch
maple_tree-rework-mas_wr_slot_store-to-be-cleaner-and-more-efficient.patch
maple_tree-simplify-and-clean-up-mas_wr_node_store.patch
maple_tree-relocate-the-declaration-of-mas_empty_area_rev.patch
