maple_tree: return error on mte_pivots() out of range

Rename mte_pivots() to mas_pivots() and pass through the ma_state to set
the error code to -EIO when the offset is out of range for the node type. 
Change the WARN_ON() to MAS_WARN_ON() to log the maple state.

Link: https://lkml.kernel.org/r/20230518145544.1722059-16-Liam.Howlett@oracle.comSigned-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vernon Yang <vernon2gm@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

lib/maple_tree.c

@@ -663,22 +663,22 @@ static inline unsigned long *ma_gaps(struct maple_node *node,
 }
 
 /*
- * mte_pivot() - Get the pivot at @piv of the maple encoded node.
- * @mn: The maple encoded node.
+ * mas_pivot() - Get the pivot at @piv of the maple encoded node.
+ * @mas: The maple state.
  * @piv: The pivot.
  *
  * Return: the pivot at @piv of @mn.
  */
-static inline unsigned long mte_pivot(const struct maple_enode *mn,
-				 unsigned char piv)
+static inline unsigned long mas_pivot(struct ma_state *mas, unsigned char piv)
 {
-	struct maple_node *node = mte_to_node(mn);
-	enum maple_type type = mte_node_type(mn);
+	struct maple_node *node = mas_mn(mas);
+	enum maple_type type = mte_node_type(mas->node);
 
-	if (piv >= mt_pivots[type]) {
-		WARN_ON(1);
+	if (MAS_WARN_ON(mas, piv >= mt_pivots[type])) {
+		mas_set_err(mas, -EIO);
 		return 0;
 	}
+
 	switch (type) {
 	case maple_arange_64:
 		return node->ma64.pivot[piv];
@@ -5394,8 +5394,8 @@ static inline int mas_alloc(struct ma_state *mas, void *entry,
 			return xa_err(mas->node);
 
 		if (!mas->index)
-			return mte_pivot(mas->node, 0);
-		return mte_pivot(mas->node, 1);
+			return mas_pivot(mas, 0);
+		return mas_pivot(mas, 1);
 	}
 
 	/* Must be walking a tree. */
@@ -5412,7 +5412,10 @@ static inline int mas_alloc(struct ma_state *mas, void *entry,
 	 */
 	min = mas->min;
 	if (mas->offset)
-		min = mte_pivot(mas->node, mas->offset - 1) + 1;
+		min = mas_pivot(mas, mas->offset - 1) + 1;
+
+	if (mas_is_err(mas))
+		return xa_err(mas->node);
 
 	if (mas->index < min)
 		mas->index = min;