read_blk
return read_blk(dst, len);
ssize_t read_blk(void *dst, size_t len);
ssize_t read_blk(void *dst, size_t len);
ssize_t read_blk(void *dst, size_t len);
nread = input->read_blk(buff, maxblk);
nread1 = input->read_blk(buf1, (size_t)maxblk);
virtual ssize_t read_blk(void *dst, size_t len);