The patch titled
Subject: maple_tree: simplify mas_is_span_wr()
has been added to the -mm mm-unstable branch. Its filename is
maple_tree-simplify-mas_is_span_wr.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-mas_is_span_wr.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 mas_is_span_wr()
Date: Wed, 24 May 2023 11:12:41 +0800
Make the code for detecting spanning writes more concise.
Link: https://lkml.kernel.org/r/20230524031247.65949-5-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 | 34 +++++++++++-----------------------
1 file changed, 11 insertions(+), 23 deletions(-)
--- a/lib/maple_tree.c~maple_tree-simplify-mas_is_span_wr
+++ a/lib/maple_tree.c
@@ -3728,43 +3728,31 @@ static inline void mas_store_root(struct
*/
static bool mas_is_span_wr(struct ma_wr_state *wr_mas)
{
- unsigned long max;
+ unsigned long max = wr_mas->r_max;
unsigned long last = wr_mas->mas->last;
- unsigned long piv = wr_mas->r_max;
enum maple_type type = wr_mas->type;
void *entry = wr_mas->entry;
- /* Contained in this pivot */
- if (piv > last)
+ /* Contained in this pivot, fast path */
+ if (last < max)
return false;
- max = wr_mas->mas->max;
- if (unlikely(ma_is_leaf(type))) {
- /* Fits in the node, but may span slots. */
+ if (ma_is_leaf(type)) {
+ max = wr_mas->mas->max;
if (last < max)
return false;
+ }
- /* Writes to the end of the node but not null. */
- if ((last == max) && entry)
- return false;
-
+ if (last == max) {
/*
- * Writing ULONG_MAX is not a spanning write regardless of the
- * value being written as long as the range fits in the node.
+ * The last entry of leaf node cannot be NULL unless it is the
+ * rightmost node (writing ULONG_MAX), otherwise it spans slots.
*/
- if ((last == ULONG_MAX) && (last == max))
- return false;
- } else if (piv == last) {
- if (entry)
- return false;
-
- /* Detect spanning store wr walk */
- if (last == ULONG_MAX)
+ if (entry || last == ULONG_MAX)
return false;
}
- trace_ma_write(__func__, wr_mas->mas, piv, entry);
-
+ trace_ma_write(__func__, wr_mas->mas, wr_mas->r_max, entry);
return true;
}
_
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
