read_block
#define read_block() \
#define read_block(io, left, right) \
static void read_block(struct vdo_completion *completion)
static int read_block(struct cxd *ci, u8 adr, u8 *data, u16 n)
static int read_block(struct inode *inode, struct folio *folio, size_t offset,
int read_block(char *buf, char *ext_buf, int buf_size, FILE *fin)