From: Liam R. Howlett <Liam.Howlett@Oracle.com>
Date: Tue, 6 Jul 2021 16:44:31 +0000 (-0400)
Subject: maple_tree: Clean up dead node checks.
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=9711d26c5e18046beece42a52e306a76769809da;p=users%2Fjedix%2Flinux-maple.git

maple_tree: Clean up dead node checks.

Depend on _mas_walk() on looping on existing nodes.
remove duplicate code in mas_range_load and mas_walk.

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
---

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index cc70ef6c606e..d870344c2538 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4779,6 +4779,38 @@ done:
 	return found;
 }
 
+/*
+ * mas_range_load() - Load the entry at an index and get the range.
+ * @mas: The maple state
+ * @*range_min: Pointer to store the minimum range the entry is valid
+ * @*range_max: Pointer to store the maximum range the entry is valid
+ *
+ * Must hold rcu_read_lock or the write lock.
+ * Find where mas->index is located and return the entry.
+ * @mas->node will point to the node containing the entry.
+ * range_min and range_max will be set accordingly.
+ *
+ * Return: The entry at mas->index or %NULL
+ */
+static inline void *mas_range_load(struct ma_state *mas,
+	   unsigned long *range_min, unsigned long *range_max)
+{
+	void *entry = NULL;
+
+	if (mas_is_none(mas) || mas_is_paused(mas))
+		mas->node = MAS_START;
+
+	/* dead nodes handled by _mas_walk */
+	if (_mas_walk(mas, range_min, range_max))
+		if (unlikely(mas->node == MAS_ROOT))
+			return mas_root(mas);
+
+	if (likely(mas->offset != MAPLE_NODE_SLOTS))
+		entry = mas_get_slot(mas, mas->offset);
+
+	return entry;
+}
+
 /**
  * mas_walk() - Search for @mas->index in the tree.
  * @mas - the maple state.
@@ -4791,24 +4823,12 @@ done:
 void *mas_walk(struct ma_state *mas)
 {
 	unsigned long range_min, range_max;
-	unsigned long index = mas->index;
 	void *entry;
 
-	if (mas_is_none(mas) || mas_is_paused(mas))
-		mas->node = MAS_START;
-
-	_mas_walk(mas, &range_min, &range_max);
-retry:
-	entry = NULL;
-	if (mas->offset != MAPLE_NODE_SLOTS)
-		entry = mas_get_slot(mas, mas->offset);
-
-	if (unlikely(mas_dead_node(mas, index)))
-		goto retry;
-
+	/* Retries on dead nodes handled by mas_range_load */
+	entry = mas_range_load(mas, &range_min, &range_max);
 	mas->index = range_min;
 	mas->last = range_max;
-
 	return entry;
 }
 
@@ -5172,42 +5192,6 @@ no_gap:
 	return -EBUSY;
 }
 
-/*
- * mas_range_load() - Load the entry at an index and get the range.
- * @mas: The maple state
- * @*range_min: Pointer to store the minimum range the entry is valid
- * @*range_max: Pointer to store the maximum range the entry is valid
- *
- * Must hold rcu_read_lock or the write lock.
- * Find where mas->index is located and return the entry.
- * @mas->node will point to the node containing the entry.
- * range_min and range_max will be set accordingly.
- *
- * Return: The entry at mas->index or %NULL
- */
-static inline void *mas_range_load(struct ma_state *mas,
-	   unsigned long *range_min, unsigned long *range_max)
-{
-	unsigned long index = mas->index;
-	void *entry;
-
-	if (mas_is_none(mas) || mas_is_paused(mas))
-		mas->node = MAS_START;
-
-	if (_mas_walk(mas, range_min, range_max))
-		if (unlikely(mas->node == MAS_ROOT))
-			return mas_root(mas);
-retry:
-	entry = NULL;
-	if (likely(mas->offset != MAPLE_NODE_SLOTS))
-		entry = mas_get_slot(mas, mas->offset);
-
-	if (unlikely(mas_dead_node(mas, index)))
-		goto retry;
-
-	return entry;
-}
-
 /*
  * _mas_find() - Finds the entry at @mas->index on MAS_START or the next entry
  * and sets @mas->index and @mas->last to the range.
@@ -5219,16 +5203,10 @@ retry:
 static void *_mas_find(struct ma_state *mas, unsigned long limit)
 {
 	if (unlikely(mas_is_start(mas))) {
-		/* First run */
-		void *entry = NULL;
-		unsigned long range_max;
-		unsigned long range_start;
+		/* First run or continue */
+		void *entry;
 
-		mas_start(mas);
-		/* Retries on dead nodes handled by mas_range_load */
-		entry = mas_range_load(mas, &range_start, &range_max);
-		mas->last = range_max;
-		mas->index = range_start;
+		entry = mas_walk(mas);
 		if (entry)
 			return entry;
 	}
@@ -5591,9 +5569,13 @@ void *mas_next(struct ma_state *mas, unsigned long max)
 		return NULL;
 
 	if (mas_is_start(mas)) {
+		void *entry;
+
 		mas->index = ++mas->last;
-		/* Retries on dead nodes handled by _mas_find */
-		return _mas_find(mas, max);
+		/* Retries on dead nodes handled by mas_walk */
+		entry = mas_walk(mas);
+		if (entry)
+			return entry;
 	}
 
 	/* Retries on dead nodes handled by _mas_next */