Abstract the calculation used to determine the number of nodes needed for
a store operation into a separate function: mas_prealloc_calc().
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
---
lib/maple_tree.c | 85 ++++++++++++++++++++++++++++--------------------
1 file changed, 50 insertions(+), 35 deletions(-)
diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 0e00a84e8e8f..e239197a57fc 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -5418,6 +5418,54 @@ void *mas_store(struct ma_state *mas, void *entry)
}
EXPORT_SYMBOL_GPL(mas_store);
+/**
+ * mas_prealloc_calc() - Calculate number of nodes needed for a
+ * store operation.
+ * @wr_mas: The maple write state
+ *
+ * Return: Number of nodes required for preallocation.
+ */
+int mas_prealloc_calc(struct ma_wr_state *wr_mas)
+{
+ struct ma_state *mas = wr_mas->mas;
+ unsigned char node_size;
+
+ if (unlikely(!mas->index && mas->last == ULONG_MAX))
+ return 1;
+
+ /* Root expand */
+ if (unlikely(mas_is_none(mas) || mas_is_ptr(mas)))
+ return 1;
+
+ if (unlikely(!mas_wr_walk(wr_mas))) {
+ /* Spanning store, use worst case for now */
+ return 1 + mas_mt_height(mas) * 3;
+ }
+
+ /* At this point, we are at the leaf node that needs to be altered. */
+ /* Exact fit, no nodes needed. */
+ if (wr_mas->r_min == mas->index && wr_mas->r_max == mas->last)
+ return 0;
+
+ mas_wr_end_piv(wr_mas);
+ node_size = mas_wr_new_end(wr_mas);
+ if (node_size >= mt_slots[wr_mas->type]) {
+ /* Split, worst case for now. */
+ return 1 + mas_mt_height(mas) * 2;
+ }
+
+ /* New root needs a singe node */
+ if (unlikely(mte_is_root(mas->node)))
+ return 1;
+
+ /* Potential spanning rebalance collapsing a node, use worst-case */
+ if (node_size - 1 <= mt_min_slots[wr_mas->type])
+ return mas_mt_height(mas) * 2 - 1;
+
+ /* node store, slot store needs one node */
+ return 1;
+}
+
/**
* mas_store_gfp() - Store a value into the tree.
* @mas: The maple state
@@ -5474,49 +5522,16 @@ EXPORT_SYMBOL_GPL(mas_store_prealloc);
int mas_preallocate(struct ma_state *mas, void *entry, gfp_t gfp)
{
MA_WR_STATE(wr_mas, mas, entry);
- unsigned char node_size;
int request = 1;
int ret;
-
- if (unlikely(!mas->index && mas->last == ULONG_MAX))
- goto ask_now;
-
mas_wr_store_setup(&wr_mas);
wr_mas.content = mas_start(mas);
- /* Root expand */
- if (unlikely(mas_is_none(mas) || mas_is_ptr(mas)))
- goto ask_now;
- if (unlikely(!mas_wr_walk(&wr_mas))) {
- /* Spanning store, use worst case for now */
- request = 1 + mas_mt_height(mas) * 3;
- goto ask_now;
- }
-
- /* At this point, we are at the leaf node that needs to be altered. */
- /* Exact fit, no nodes needed. */
- if (wr_mas.r_min == mas->index && wr_mas.r_max == mas->last)
+ request = mas_prealloc_calc(&wr_mas);
+ if (!request)
return 0;
- mas_wr_end_piv(&wr_mas);
- node_size = mas_wr_new_end(&wr_mas);
- if (node_size >= mt_slots[wr_mas.type]) {
- /* Split, worst case for now. */
- request = 1 + mas_mt_height(mas) * 2;
- goto ask_now;
- }
-
- /* New root needs a singe node */
- if (unlikely(mte_is_root(mas->node)))
- goto ask_now;
-
- /* Potential spanning rebalance collapsing a node, use worst-case */
- if (node_size - 1 <= mt_min_slots[wr_mas.type])
- request = mas_mt_height(mas) * 2 - 1;
-
- /* node store, slot store needs one node */
-ask_now:
mas_node_count_gfp(mas, request, gfp);
mas->mas_flags |= MA_STATE_PREALLOC;
if (likely(!mas_is_err(mas)))
--
2.41.0
