btrfs: backref: rename and move backref_cache_cleanup()

Since we're releasing all existing nodes/edges, other than cleanup the
mess after error, "release" is a more proper naming here.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/backref.c

@@ -2559,3 +2559,36 @@ void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
 
 	btrfs_backref_drop_node(cache, node);
 }
+
+/*
+ * Release all nodes/edges from current cache
+ */
+void btrfs_backref_release_cache(struct btrfs_backref_cache *cache)
+{
+	struct btrfs_backref_node *node;
+	int i;
+
+	while (!list_empty(&cache->detached)) {
+		node = list_entry(cache->detached.next,
+				  struct btrfs_backref_node, list);
+		btrfs_backref_cleanup_node(cache, node);
+	}
+
+	while (!list_empty(&cache->leaves)) {
+		node = list_entry(cache->leaves.next,
+				  struct btrfs_backref_node, lower);
+		btrfs_backref_cleanup_node(cache, node);
+	}
+
+	cache->last_trans = 0;
+
+	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
+		ASSERT(list_empty(&cache->pending[i]));
+	ASSERT(list_empty(&cache->pending_edge));
+	ASSERT(list_empty(&cache->useless_node));
+	ASSERT(list_empty(&cache->changed));
+	ASSERT(list_empty(&cache->detached));
+	ASSERT(RB_EMPTY_ROOT(&cache->rb_root));
+	ASSERT(!cache->nr_nodes);
+	ASSERT(!cache->nr_edges);
+}

fs/btrfs/backref.h

@@ -353,4 +353,6 @@ static inline void btrfs_backref_drop_node(struct btrfs_backref_cache *tree,
 void btrfs_backref_cleanup_node(struct btrfs_backref_cache *cache,
 				struct btrfs_backref_node *node);
 
+void btrfs_backref_release_cache(struct btrfs_backref_cache *cache);
+
 #endif

fs/btrfs/relocation.c

@@ -175,36 +175,6 @@ static void mapping_tree_init(struct mapping_tree *tree)
 	spin_lock_init(&tree->lock);
 }
 
-static void backref_cache_cleanup(struct btrfs_backref_cache *cache)
-{
-	struct btrfs_backref_node *node;
-	int i;
-
-	while (!list_empty(&cache->detached)) {
-		node = list_entry(cache->detached.next,
-				  struct btrfs_backref_node, list);
-		btrfs_backref_cleanup_node(cache, node);
-	}
-
-	while (!list_empty(&cache->leaves)) {
-		node = list_entry(cache->leaves.next,
-				  struct btrfs_backref_node, lower);
-		btrfs_backref_cleanup_node(cache, node);
-	}
-
-	cache->last_trans = 0;
-
-	for (i = 0; i < BTRFS_MAX_LEVEL; i++)
-		ASSERT(list_empty(&cache->pending[i]));
-	ASSERT(list_empty(&cache->pending_edge));
-	ASSERT(list_empty(&cache->useless_node));
-	ASSERT(list_empty(&cache->changed));
-	ASSERT(list_empty(&cache->detached));
-	ASSERT(RB_EMPTY_ROOT(&cache->rb_root));
-	ASSERT(!cache->nr_nodes);
-	ASSERT(!cache->nr_edges);
-}
-
 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
 {
 
@@ -3948,7 +3918,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
 	rc->create_reloc_tree = 0;
 	set_reloc_control(rc);
 
-	backref_cache_cleanup(&rc->backref_cache);
+	btrfs_backref_release_cache(&rc->backref_cache);
 	btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL);
 
 	/*