A check in mas_walk() was incorrect and caused inefficient use of the
maple state.  The same issue existed in mas_erase(), but was left
unfixed.  Making a helper function is the obvious answer.

Signed-off-by: Liam R. Howlett (Oracle) <liam@infradead.org>
---
 lib/maple_tree.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 4336a98763984..06cc05b79fbdc 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -261,6 +261,12 @@ static inline bool mas_is_underflow(struct ma_state *mas)
 	return mas->status == ma_underflow;
 }
 
+static inline void mas_make_walkable(struct ma_state *mas)
+{
+	if (!mas_is_active(mas) && !mas_is_start(mas))
+		mas->status = ma_start;
+}
+
 static __always_inline struct maple_node *mte_to_node(
 		const struct maple_enode *entry)
 {
@@ -4446,8 +4452,7 @@ void *mas_walk(struct ma_state *mas)
 	void *entry;
 
 	mas_may_init_lock_check(mas);
-	if (!mas_is_active(mas) && !mas_is_start(mas))
-		mas->status = ma_start;
+	mas_make_walkable(mas);
 retry:
 	entry = mas_state_walk(mas);
 	if (mas_is_start(mas)) {
@@ -5683,9 +5688,7 @@ void *mas_erase(struct ma_state *mas)
 	if (mt_external_lock(mas->tree))
 		might_alloc(GFP_KERNEL);
 
-	if (!mas_is_active(mas) || !mas_is_start(mas))
-		mas->status = ma_start;
-
+	mas_make_walkable(mas);
 write_retry:
 	entry = mas_state_walk(mas);
 	if (!entry)
-- 
2.47.3