mm: zswap: function ordering: move entry section out of tree section

The higher-level entry operations modify the tree, so move the entry
API after the tree section.

Link: https://lkml.kernel.org/r/20240130014208.565554-17-hannes@cmpxchg.orgSigned-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Nhat Pham <nphamcs@gmail.com>
Cc: Chengming Zhou <zhouchengming@bytedance.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/zswap.c

@@ -848,27 +848,6 @@ void zswap_memcg_offline_cleanup(struct mem_cgroup *memcg)
 	spin_unlock(&zswap_pools_lock);
 }
 
-/*********************************
-* zswap entry functions
-**********************************/
-static struct kmem_cache *zswap_entry_cache;
-
-static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp, int nid)
-{
-	struct zswap_entry *entry;
-	entry = kmem_cache_alloc_node(zswap_entry_cache, gfp, nid);
-	if (!entry)
-		return NULL;
-	entry->refcount = 1;
-	RB_CLEAR_NODE(&entry->rbnode);
-	return entry;
-}
-
-static void zswap_entry_cache_free(struct zswap_entry *entry)
-{
-	kmem_cache_free(zswap_entry_cache, entry);
-}
-
 /*********************************
 * rbtree functions
 **********************************/
@@ -930,6 +909,27 @@ static bool zswap_rb_erase(struct rb_root *root, struct zswap_entry *entry)
 	return false;
 }
 
+/*********************************
+* zswap entry functions
+**********************************/
+static struct kmem_cache *zswap_entry_cache;
+
+static struct zswap_entry *zswap_entry_cache_alloc(gfp_t gfp, int nid)
+{
+	struct zswap_entry *entry;
+	entry = kmem_cache_alloc_node(zswap_entry_cache, gfp, nid);
+	if (!entry)
+		return NULL;
+	entry->refcount = 1;
+	RB_CLEAR_NODE(&entry->rbnode);
+	return entry;
+}
+
+static void zswap_entry_cache_free(struct zswap_entry *entry)
+{
+	kmem_cache_free(zswap_entry_cache, entry);
+}
+
 static struct zpool *zswap_find_zpool(struct zswap_entry *entry)
 {
 	int i = 0;