有关链表的文件读取问题，求高手大大们解决一下

#include<stdio.h>
#include<stdlib.h>
#include <string.h>

#define ERROR 0
#define OK 1
#define OVERFLOW -1
#define Status int
#define MAXSIZE 100
char filename[20];

typedef struct
{
    char no[4];
    char name[8];
    int price;
}Student;
struct SqList
{
    Student elem;
    struct SqList *next;
};

int menu_filename()
{
    system("cls");
    printf("请输入你要操作的文件名:");
    scanf("\t%s", filename);
}



Status InitList(struct SqList *L)//初始化
{
    L->next = NULL;
    return OK;
}
void DisplayList(struct SqList *L)//显示学生信息
{
    FILE *fp;
    struct SqList *tmp = L->next;
    if ((fp = fopen(filename, "r")) == NULL)             //以2进制方式读取文件信息//  
    {
        printf("cannot open the files\n");
        return;
    }
    while (!feof(fp))
    {
        fread(&L, sizeof(Student), 1, fp);                      //以2进制方式将文件信息读到链表内存中//一次读取一个//  
        L= L->next;
    }
    fclose(fp);
    while (tmp != NULL)
    {
        printf("学号:%s姓名:%s分数:%d\n", tmp->elem.no, tmp->elem.name, tmp->elem.price);
        tmp = tmp->next;
    }
}

Status Searchelem(struct SqList *L, int i)//3查找对应的数据元素
{
    FILE *fp;
    struct SqList *tmp = L->next;
    int j = 1;

    if ((fp = fopen(filename, "r")) == NULL)                 //以2进制方式读取文件信息//  
    {
        printf("cannot open the files\n");
        system("pause");
        return;
    }
    while (!feof(fp))
    {
        fread(&tmp, sizeof(Student), 1, fp);                      //以2进制方式将文件信息读到链表内存中//一次读取一个//  
        L = L->next;
    }


    while (tmp != NULL) {
        if (i == j)
        {
            printf("第%d号：学号: %s姓名: %s分数: %d\n", i, tmp->elem.no, tmp->elem.name, tmp->elem.price);
            return OK;
        }
        tmp = tmp->next;
        j++;
    }
    return ERROR;
}

Status SearchElemName(struct SqList *L, char e[])//根据姓名查找
{
    FILE *fp;
    printf("查找\n");
    struct SqList *tmp = L->next;
    if ((fp = fopen(filename, "r")) == NULL)                 //以2进制方式读取文件信息//  
    {
        printf("cannot open the files\n");
        system("pause");
        return;
    }

    while (!feof(fp))
    {
        fread(&L, sizeof(Student), 1, fp);                      //以2进制方式将文件信息读到链表内存中//一次读取一个//  
        L = L->next;
    }

    while (tmp != NULL)
    {
        if (!strcmp(tmp->elem.name, e)) {
            printf("学号为%s,姓名为%s, 分数是%d\n", tmp->elem.no, tmp->elem.name, tmp->elem.price);
            return OK;
        }
        tmp = tmp->next;
    }

    return ERROR;
}

Status InsertList(struct SqList *L, Student e)//4插入一个数据元素 头插
{
    FILE *fp;
    struct SqList *tmp = L;
    struct SqList *new = (struct SqList *)malloc(sizeof(struct SqList));
    new->elem = e;
    new->next = tmp->next;
    tmp->next = new;
   
    if ((fp = fopen(filename, "a")) == NULL)                    //以2进制形式进行文件尾追加//  
    {
        printf("cannot open the files\n");
        return;                                         //如果文件出现错误 就返回  
    }
    while(L->next!=NULL)
    {
        if (fwrite(&L, sizeof(Student), 1, fp) != 1)  //以2进制形式写入文件中//一次写入一个结点//  
            printf("file write error\n");
           L = L->next;
    }fclose(fp);                                       //关闭文件
}

Status DeleteList(struct SqList *L, int i)//5删除一个数据元素
{
    FILE *fp;
    struct SqList *tmp = L;
    struct SqList *del;
    int j = 0;
    if ((fp = fopen(filename, "r")) == NULL)                 //以2进制方式读取文件信息//  
    {
        printf("cannot open the files\n");
        system("pause");
        return;
    }
    while (!feof(fp))
    {
        fread(&tmp, sizeof(Student), 1, fp);
        L=L->next;
    }i = 0;
    fclose(fp);

    if (i < 1)
        return ERROR;

    while (tmp != NULL)
    {
        if (j == i - 1)
        {
            del = tmp->next;
            if (del == NULL)
                break;
            tmp->next = del->next;
            free(del);
            return OK;
        }
        tmp = tmp->next;
        j++;

    }

    return ERROR;

}
Status ClearList(struct SqList *L)//6清空顺序表
{
    FILE *fp;
    if ((fp = fopen(filename, "r")) == NULL)                 //以2进制方式读取文件信息//  
    {
        printf("cannot open the files\n");
        system("pause");
        return;
    }
    while (!feof(fp))
    {
        fread(&L, sizeof(Student), 1, fp);
        L= L->next;
    };
    fclose(fp);
    L->next = NULL;
    return OK;
}
Status DestorySqList(struct SqList *L)//7销毁顺序表
{
    L->next = NULL;
    return OK;
}
int LengthList(struct SqList *L)//10取表的长度
{
    int j = 0;
    struct SqList *tmp = L->next;

    while (tmp != NULL)
    {
        j++;
        tmp = tmp->next;
    }
    return j;
}

int main()
{
    menu_filename();
    struct SqList *L = (struct SqList *)malloc(sizeof(struct SqList));
    Student e;
    int number, N;
    int no;
    int i, j;
    char na[20];
    printf("\n");
    printf("    欢迎使用学生信息管理系统（c语言任性版）！\n\n");
    printf("      ******************************\n");
    printf("      **    1-创建学生信息表      **\n");
    printf("      **    2-查找学生信息表      **\n");
    printf("      **    3-显示学生信息        **\n");
    printf("      **    4-删除信息表          **\n");
    printf("      **    5-插入学生信息        **\n");
    printf("      **    6-显示学生个数        **\n");
    printf("      **    7-根据姓名查找        **\n");
    printf("      **    0-退出程序            **\n");
    printf("      *****************************\n");
    number = 1;
    InitList(L);

    while (number)
    {
        printf("请选择功能序号: ");
        scanf("%d", &no);
        switch (no)
        {
        case 1:
            printf("创建成绩表,请输入您要输入学生人数：");
            scanf("%d", &N);
            for (j = 0;j < N;j++)
            {
                printf("请输入要插入学生的信息:\n 注：格式为 学号 姓名 分数,每个数据之间空格隔开\n\n");
                scanf("%s%s%d", e.no, e.name, &e.price);
                InsertList(L, e);
            }
            break;
        case 2:
            printf("请输入您要查找的序号: ");
            scanf("%d", &i);
            if (Searchelem(L, i))
                printf("查找成功！\n");
            else
                printf("查找失败\n");
            break;
        case 3:
            DisplayList(L);
            break;
        case 4:
            printf("请输入第i个元素: ");
            scanf("%d", &i);
            if (DeleteList(L, i))
                printf("删除成功\n");
            else
                printf("删除失败\n");
            break;
        case 5:
            printf("请输入要插入学生的信息:\n 注：格式为 学号 姓名 分数,每个数据之间空格隔开\n");
            scanf("%s%s%d", e.no, e.name, &e.price);
            if (InsertList(L, e))
                printf("插入成功");
            else
                printf("插入失败");
            break;
        case 6:
            printf("一共有%d个学生信息！\n", LengthList(L));
            break;
        case 7:
            printf("请输入要查找的名字");
            scanf("%s", na);
            number = 0;
            break;
            if (SearchElemName(L, na))
                printf("查找成功");
            else
                printf("查找失败\n");
            break;
        default:
            number = 0;
            break;
        }
    }
    return 0;
}