btrfs_get_chunk_map
map = btrfs_get_chunk_map(fs_info, chunk_start, 1);
map = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
map = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
map = btrfs_get_chunk_map(fs_info, bg->start, 1);
map = btrfs_get_chunk_map(fs_info, logical_block_start, len);
map = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
map = btrfs_get_chunk_map(fs_info, bg->start, bg->length);
map = btrfs_get_chunk_map(fs_info, chunk_offset, 1);
map = btrfs_get_chunk_map(fs_info, logical, len);
map = btrfs_get_chunk_map(fs_info, logical, len);
map = btrfs_get_chunk_map(fs_info, logical, length);
map = btrfs_get_chunk_map(fs_info, new_logical, length);
map = btrfs_get_chunk_map(fs_info, logical, *length);
map = btrfs_get_chunk_map(fs_info, new_logical, *length);
struct btrfs_chunk_map *btrfs_get_chunk_map(struct btrfs_fs_info *fs_info,