[v2 PATCH 2/5] mm: mempool: extract the common initialization and alloc code

[Yang Shi <shy828301@xxxxxxxxx>]

Extract the common initialization code to __mempool_init() and
__mempool_create().  And extract the common alloc code into an internal
function.  This will make the following patch easier and avoid duplicate
code.

Signed-off-by: Yang Shi <shy828301@xxxxxxxxx>
---
 mm/mempool.c | 93 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 57 insertions(+), 36 deletions(-)

diff --git a/mm/mempool.c b/mm/mempool.c
index 734bcf5afbb7..975c9d1491b6 100644
--- a/mm/mempool.c
+++ b/mm/mempool.c
@@ -182,9 +182,10 @@ void mempool_destroy(mempool_t *pool)
 }
 EXPORT_SYMBOL(mempool_destroy);
 
-int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
-		      mempool_free_t *free_fn, void *pool_data,
-		      gfp_t gfp_mask, int node_id)
+static inline int __mempool_init(mempool_t *pool, int min_nr,
+				 mempool_alloc_t *alloc_fn,
+				 mempool_free_t *free_fn, void *pool_data,
+				 gfp_t gfp_mask, int node_id)
 {
 	spin_lock_init(&pool->lock);
 	pool->min_nr	= min_nr;
@@ -214,6 +215,14 @@ int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
 
 	return 0;
 }
+
+int mempool_init_node(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
+		      mempool_free_t *free_fn, void *pool_data,
+		      gfp_t gfp_mask, int node_id)
+{
+	return __mempool_init(pool, min_nr, alloc_fn, free_fn, pool_data,
+			      gfp_mask, node_id);
+}
 EXPORT_SYMBOL(mempool_init_node);
 
 /**
@@ -233,12 +242,30 @@ EXPORT_SYMBOL(mempool_init_node);
 int mempool_init(mempool_t *pool, int min_nr, mempool_alloc_t *alloc_fn,
 		 mempool_free_t *free_fn, void *pool_data)
 {
-	return mempool_init_node(pool, min_nr, alloc_fn, free_fn,
-				 pool_data, GFP_KERNEL, NUMA_NO_NODE);
-
+	return __mempool_init(pool, min_nr, alloc_fn, free_fn,
+			      pool_data, GFP_KERNEL, NUMA_NO_NODE);
 }
 EXPORT_SYMBOL(mempool_init);
 
+static mempool_t *__mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
+				   mempool_free_t *free_fn, void *pool_data,
+				   gfp_t gfp_mask, int node_id)
+{
+	mempool_t *pool;
+
+	pool = kzalloc_node(sizeof(*pool), gfp_mask, node_id);
+	if (!pool)
+		return NULL;
+
+	if (__mempool_init(pool, min_nr, alloc_fn, free_fn, pool_data,
+			   gfp_mask, node_id)) {
+		kfree(pool);
+		return NULL;
+	}
+
+	return pool;
+}
+
 /**
  * mempool_create - create a memory pool
  * @min_nr:    the minimum number of elements guaranteed to be
@@ -258,8 +285,8 @@ EXPORT_SYMBOL(mempool_init);
 mempool_t *mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
 				mempool_free_t *free_fn, void *pool_data)
 {
-	return mempool_create_node(min_nr, alloc_fn, free_fn, pool_data,
-				   GFP_KERNEL, NUMA_NO_NODE);
+	return __mempool_create(min_nr, alloc_fn, free_fn, pool_data,
+				GFP_KERNEL, NUMA_NO_NODE);
 }
 EXPORT_SYMBOL(mempool_create);
 
@@ -267,19 +294,8 @@ mempool_t *mempool_create_node(int min_nr, mempool_alloc_t *alloc_fn,
 			       mempool_free_t *free_fn, void *pool_data,
 			       gfp_t gfp_mask, int node_id)
 {
-	mempool_t *pool;
-
-	pool = kzalloc_node(sizeof(*pool), gfp_mask, node_id);
-	if (!pool)
-		return NULL;
-
-	if (mempool_init_node(pool, min_nr, alloc_fn, free_fn, pool_data,
-			      gfp_mask, node_id)) {
-		kfree(pool);
-		return NULL;
-	}
-
-	return pool;
+	return __mempool_create(min_nr, alloc_fn, free_fn, pool_data,
+				gfp_mask, node_id);
 }
 EXPORT_SYMBOL(mempool_create_node);
 
@@ -363,21 +379,7 @@ int mempool_resize(mempool_t *pool, int new_min_nr)
 }
 EXPORT_SYMBOL(mempool_resize);
 
-/**
- * mempool_alloc - allocate an element from a specific memory pool
- * @pool:      pointer to the memory pool which was allocated via
- *             mempool_create().
- * @gfp_mask:  the usual allocation bitmask.
- *
- * this function only sleeps if the alloc_fn() function sleeps or
- * returns NULL. Note that due to preallocation, this function
- * *never* fails when called from process contexts. (it might
- * fail if called from an IRQ context.)
- * Note: using __GFP_ZERO is not supported.
- *
- * Return: pointer to the allocated element or %NULL on error.
- */
-void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
+static void *__mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
 {
 	void *element;
 	unsigned long flags;
@@ -444,6 +446,25 @@ void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
 	finish_wait(&pool->wait, &wait);
 	goto repeat_alloc;
 }
+
+/**
+ * mempool_alloc - allocate an element from a specific memory pool
+ * @pool:      pointer to the memory pool which was allocated via
+ *             mempool_create().
+ * @gfp_mask:  the usual allocation bitmask.
+ *
+ * this function only sleeps if the alloc_fn() function sleeps or
+ * returns NULL. Note that due to preallocation, this function
+ * *never* fails when called from process contexts. (it might
+ * fail if called from an IRQ context.)
+ * Note: using __GFP_ZERO is not supported.
+ *
+ * Return: pointer to the allocated element or %NULL on error.
+ */
+void *mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
+{
+	return __mempool_alloc(pool, gfp_mask);
+}
 EXPORT_SYMBOL(mempool_alloc);
 
 /**
-- 
2.39.0