kaddr = kmap_atomic(su_bh[i]->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum[i], su_bh[i], kaddr);
kaddr = kmap_atomic(su_bh[i]->b_page, KM_USER0);
su = nilfs_sufile_block_get_segment_usage(
sufile, segnum[i], su_bh[i], kaddr);