void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount)
{
	spin_lock(&bg->lock);
	ASSERT(!bg->ro);
	ASSERT(bg->swap_extents >= amount);
	bg->swap_extents -= amount;
	spin_unlock(&bg->lock);
}
void btrfs_dec_block_group_swap_extents(struct btrfs_block_group *bg, int amount)
{
	spin_lock(&bg->lock);
	ASSERT(!bg->ro);
	ASSERT(bg->swap_extents >= amount);
	bg->swap_extents -= amount;
	spin_unlock(&bg->lock);
}