btrfs: reduce arguments of helpers space accounting root item

There are two helpers to increase used bytes of root items that add or
subtract one node size, we don't need to pass the argument for that.
Rename the function so it matches the root item member that gets
changed.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ctree.c

@@ -973,19 +973,19 @@ int btrfs_bin_search(struct extent_buffer *eb, int first_slot,
 	return 1;
 }
 
-static void root_add_used(struct btrfs_root *root, u32 size)
+static void root_add_used_bytes(struct btrfs_root *root)
 {
 	spin_lock(&root->accounting_lock);
 	btrfs_set_root_used(&root->root_item,
-			    btrfs_root_used(&root->root_item) + size);
+		btrfs_root_used(&root->root_item) + root->fs_info->nodesize);
 	spin_unlock(&root->accounting_lock);
 }
 
-static void root_sub_used(struct btrfs_root *root, u32 size)
+static void root_sub_used_bytes(struct btrfs_root *root)
 {
 	spin_lock(&root->accounting_lock);
 	btrfs_set_root_used(&root->root_item,
-			    btrfs_root_used(&root->root_item) - size);
+		btrfs_root_used(&root->root_item) - root->fs_info->nodesize);
 	spin_unlock(&root->accounting_lock);
 }
 
@@ -1101,7 +1101,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 		/* once for the path */
 		free_extent_buffer(mid);
 
-		root_sub_used(root, mid->len);
+		root_sub_used_bytes(root);
 		btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
 		/* once for the root ptr */
 		free_extent_buffer_stale(mid);
@@ -1171,7 +1171,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 				right = NULL;
 				goto out;
 			}
-			root_sub_used(root, right->len);
+			root_sub_used_bytes(root);
 			btrfs_free_tree_block(trans, btrfs_root_id(root), right,
 					      0, 1);
 			free_extent_buffer_stale(right);
@@ -1229,7 +1229,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
 			mid = NULL;
 			goto out;
 		}
-		root_sub_used(root, mid->len);
+		root_sub_used_bytes(root);
 		btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1);
 		free_extent_buffer_stale(mid);
 		mid = NULL;
@@ -2963,7 +2963,6 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root,
 			   struct btrfs_path *path, int level)
 {
-	struct btrfs_fs_info *fs_info = root->fs_info;
 	u64 lower_gen;
 	struct extent_buffer *lower;
 	struct extent_buffer *c;
@@ -2986,7 +2985,7 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 	if (IS_ERR(c))
 		return PTR_ERR(c);
 
-	root_add_used(root, fs_info->nodesize);
+	root_add_used_bytes(root);
 
 	btrfs_set_header_nritems(c, 1);
 	btrfs_set_node_key(c, &lower_key, 0);
@@ -3130,7 +3129,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
 	if (IS_ERR(split))
 		return PTR_ERR(split);
 
-	root_add_used(root, fs_info->nodesize);
+	root_add_used_bytes(root);
 	ASSERT(btrfs_header_level(c) == level);
 
 	ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid);
@@ -3883,7 +3882,7 @@ static noinline int split_leaf(struct btrfs_trans_handle *trans,
 	if (IS_ERR(right))
 		return PTR_ERR(right);
 
-	root_add_used(root, fs_info->nodesize);
+	root_add_used_bytes(root);
 
 	if (split == 0) {
 		if (mid <= slot) {
@@ -4556,7 +4555,7 @@ static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans,
 	 */
 	btrfs_unlock_up_safe(path, 0);
 
-	root_sub_used(root, leaf->len);
+	root_sub_used_bytes(root);
 
 	atomic_inc(&leaf->refs);
 	btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1);