BTRFS_FS_CSUM_IMPL_FAST  873 fs/btrfs/disk-io.c 	if (test_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags))
BTRFS_FS_CSUM_IMPL_FAST 1560 fs/btrfs/super.c 			set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);