void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
					const u64 start)
{
	struct btrfs_block_group *bg;

	bg = btrfs_lookup_block_group(fs_info, start);
	ASSERT(bg);
	if (atomic_dec_and_test(&bg->reservations))
		wake_up_var(&bg->reservations);
	btrfs_put_block_group(bg);
}
void btrfs_dec_block_group_reservations(struct btrfs_fs_info *fs_info,
					const u64 start)
{
	struct btrfs_block_group *bg;

	bg = btrfs_lookup_block_group(fs_info, start);
	ASSERT(bg);
	if (atomic_dec_and_test(&bg->reservations))
		wake_up_var(&bg->reservations);
	btrfs_put_block_group(bg);
}