btrfs_del_csums
ret = btrfs_del_csums(trans, csum_root, head->bytenr,
ret = btrfs_del_csums(trans, csum_root, bytenr, num_bytes);
int btrfs_del_csums(struct btrfs_trans_handle *trans,
ret = btrfs_del_csums(trans, log_root, sums->logical, sums->len);
ret = btrfs_del_csums(trans, csum_root, sums->logical,