block_map
static int block_map(struct open_file *, indp_t, indp_t *);
rc = block_map(f, file_block, &disk_block);
rc = block_map(f, (indp_t)0, &disk_block);
static int block_map(struct open_file *, block_t, block_t *);
rc = block_map(f, file_block, &disk_block);
rc = block_map(f, (block_t)0, &disk_block);
static int block_map(struct open_file *, indp_t, indp_t *);
rc = block_map(f, file_block, &disk_block);
rc = block_map(f, (indp_t)0, &disk_block);