BigOS/kernel/vfs.c

/**********************************************************
 *	vfs.c       //added by mingxuan 2019-5-17
 ***********************************************************/

#include "type.h"
#include "const.h"
#include "protect.h"
#include "string.h"
#include "proc.h"
#include "global.h"
#include "proto.h"
#include "fs_const.h"
#include "hd.h"
#include "fs.h"
#include "fs_misc.h"
#include "vfs.h"
#include "fat32.h"
#include "stdio.h"

// static struct device  device_table[NR_DEV];  //deleted by mingxuan 2020-10-18
static struct vfs vfs_table[NR_FS]; // modified by mingxuan 2020-10-18

struct file_desc f_desc_table[NR_FILE_DESC];
struct super_block super_block[NR_SUPER_BLOCK]; // added by mingxuan 2020-10-30

// static struct file_op f_op_table[NR_fs]; //文件系统操作表
static struct file_op f_op_table[NR_FS_OP]; // modified by mingxuan 2020-10-18
static struct sb_op sb_op_table[NR_SB_OP];  // added by mingxuan 2020-10-30

// static void init_dev_table();//deleted by mingxuan 2020-10-30
static void init_vfs_table(); // modified by mingxuan 2020-10-30
void init_file_desc_table();  // added by mingxuan 2020-10-30
void init_fileop_table();
void init_super_block_table(); // added by mingxuan 2020-10-30
void init_sb_op_table();

static int get_index(char path[]);

void init_vfs()
{

    init_file_desc_table();
    init_fileop_table();

    init_super_block_table();
    init_sb_op_table(); // added by mingxuan 2020-10-30

    // init_dev_table(); //deleted by mingxuan 2020-10-30
    init_vfs_table(); // modified by mingxuan 2020-10-30
}

// added by mingxuan 2020-10-30
void init_file_desc_table()
{
    int i;
    for (i = 0; i < NR_FILE_DESC; i++)
        memset(&f_desc_table[i], 0, sizeof(struct file_desc));
}

void init_fileop_table()
{
    // table[0] for tty
    f_op_table[0].open = real_open;
    f_op_table[0].close = real_close;
    f_op_table[0].write = real_write;
    f_op_table[0].lseek = real_lseek;
    f_op_table[0].unlink = real_unlink;
    f_op_table[0].read = real_read;

    // table[1] for orange
    f_op_table[1].open = real_open;
    f_op_table[1].close = real_close;
    f_op_table[1].write = real_write;
    f_op_table[1].lseek = real_lseek;
    f_op_table[1].unlink = real_unlink;
    f_op_table[1].read = real_read;

    // table[2] for fat32
    f_op_table[2].create = CreateFile;
    f_op_table[2].delete = DeleteFile;
    f_op_table[2].open = OpenFile;
    f_op_table[2].close = CloseFile;
    f_op_table[2].write = WriteFile;
    f_op_table[2].read = ReadFile;
    f_op_table[2].opendir = OpenDir;
    f_op_table[2].createdir = CreateDir;
    f_op_table[2].deletedir = DeleteDir;
}

// added by mingxuan 2020-10-30
void init_super_block_table()
{
    struct super_block *sb = super_block; // deleted by mingxuan 2020-10-30

    // super_block[0] is tty0, super_block[1] is tty1, uper_block[2] is tty2
    for (; sb < &super_block[3]; sb++)
    {
        sb->sb_dev = DEV_CHAR_TTY;
        sb->fs_type = TTY_FS_TYPE;
    }

    // super_block[3] is orange's superblock
    sb->sb_dev = DEV_HD;
    sb->fs_type = ORANGE_TYPE;
    sb++;

    // super_block[4] is fat32's superblock
    sb->sb_dev = DEV_HD;
    sb->fs_type = FAT32_TYPE;
    sb++;

    // another super_block are free
    for (; sb < &super_block[NR_SUPER_BLOCK]; sb++)
    {
        sb->sb_dev = NO_DEV;
        sb->fs_type = NO_FS_TYPE;
    }
}

// added by mingxuan 2020-10-30
void init_sb_op_table()
{
    // orange
    sb_op_table[0].read_super_block = read_super_block;
    sb_op_table[0].get_super_block = get_super_block;

    // fat32 and tty
    sb_op_table[1].read_super_block = NULL;
    sb_op_table[1].get_super_block = NULL;
}

// static void init_dev_table(){
static void init_vfs_table()
{ // modified by mingxuan 2020-10-30

    // 我们假设每个tty就是一个文件系统
    // tty0
    // device_table[0].dev_name="dev_tty0";
    // device_table[0].op = &f_op_table[0];
    vfs_table[0].fs_name = "dev_tty0"; // modifed by mingxuan 2020-10-18
    vfs_table[0].op = &f_op_table[0];
    vfs_table[0].sb = &super_block[0];   // 每个tty都有一个superblock //added by mingxuan 2020-10-30
    vfs_table[0].s_op = &sb_op_table[1]; // added by mingxuan 2020-10-30

    // tty1
    // device_table[1].dev_name="dev_tty1";
    // device_table[1].op =&f_op_table[0];
    vfs_table[1].fs_name = "dev_tty1"; // modifed by mingxuan 2020-10-18
    vfs_table[1].op = &f_op_table[0];
    vfs_table[1].sb = &super_block[1];   // 每个tty都有一个superblock //added by mingxuan 2020-10-30
    vfs_table[1].s_op = &sb_op_table[1]; // added by mingxuan 2020-10-30

    // tty2
    // device_table[2].dev_name="dev_tty2";
    // device_table[2].op=&f_op_table[0];
    vfs_table[2].fs_name = "dev_tty2"; // modifed by mingxuan 2020-10-18
    vfs_table[2].op = &f_op_table[0];
    vfs_table[2].sb = &super_block[2];   // 每个tty都有一个superblock //added by mingxuan 2020-10-30
    vfs_table[2].s_op = &sb_op_table[1]; // added by mingxuan 2020-10-30

    // fat32
    // device_table[3].dev_name="fat0";
    // device_table[3].op=&f_op_table[2];
    vfs_table[3].fs_name = "fat0"; // modifed by mingxuan 2020-10-18
    vfs_table[3].op = &f_op_table[2];
    vfs_table[3].sb = &super_block[4];   // added by mingxuan 2020-10-30
    vfs_table[3].s_op = &sb_op_table[1]; // added by mingxuan 2020-10-30

    // orange
    // device_table[4].dev_name="orange";
    // device_table[4].op=&f_op_table[1];
    vfs_table[4].fs_name = "orange"; // modifed by mingxuan 2020-10-18
    vfs_table[4].op = &f_op_table[1];
    vfs_table[4].sb = &super_block[3];   // added by mingxuan 2020-10-30
    vfs_table[4].s_op = &sb_op_table[0]; // added by mingxuan 2020-10-30
}

static int get_index(char path[])
{

    int pathlen = strlen(path);
    // char dev_name[DEV_NAME_LEN];
    char fs_name[DEV_NAME_LEN]; // modified by mingxuan 2020-10-18
    int len = (pathlen < DEV_NAME_LEN) ? pathlen : DEV_NAME_LEN;

    int i, a = 0;
    for (i = 0; i < len; i++)
    {
        if (path[i] == '/')
        {
            a = i;
            a++;
            break;
        }
        else
        {
            // dev_name[i] = path[i];
            fs_name[i] = path[i]; // modified by mingxuan 2020-10-18
        }
    }
    // dev_name[i] = '\0';
    fs_name[i] = '\0'; // modified by mingxuan 2020-10-18
    for (i = 0; i < pathlen - a; i++)
        path[i] = path[i + a];
    path[pathlen - a] = '\0';

    // for(i=0;i<NR_DEV;i++)
    for (i = 0; i < NR_FS; i++) // modified by mingxuan 2020-10-29
    {
        // if(!strcmp(dev_name, device_table[i].dev_name))
        if (!strcmp(fs_name, vfs_table[i].fs_name)) // modified by mingxuan 2020-10-18
            return i;
    }

    return -1;
}

/*======================================================================*
                              sys_* 系列函数
 *======================================================================*/

int sys_open(void *uesp)
{
    return do_vopen((const char *)get_arg(uesp, 1), get_arg(uesp, 2));
}

int sys_close(void *uesp)
{
    return do_vclose(get_arg(uesp, 1));
}

int sys_read(void *uesp)
{
    return do_vread(get_arg(uesp, 1), (char *)get_arg(uesp, 2), get_arg(uesp, 3));
}

int sys_write(void *uesp)
{
    return do_vwrite(get_arg(uesp, 1), (const char *)get_arg(uesp, 2), get_arg(uesp, 3));
}

int sys_lseek(void *uesp)
{
    return do_vlseek(get_arg(uesp, 1), get_arg(uesp, 2), get_arg(uesp, 3));
}

int sys_unlink(void *uesp)
{
    return do_vunlink((const char *)get_arg(uesp, 1));
}

int sys_create(void *uesp)
{
    return do_vcreate((char *)get_arg(uesp, 1));
}

int sys_delete(void *uesp)
{
    return do_vdelete((char *)get_arg(uesp, 1));
}

int sys_opendir(void *uesp)
{
    return do_vopendir((char *)get_arg(uesp, 1));
}

int sys_createdir(void *uesp)
{
    return do_vcreatedir((char *)get_arg(uesp, 1));
}

int sys_deletedir(void *uesp)
{
    return do_vdeletedir((char *)get_arg(uesp, 1));
}

/*======================================================================*
                              do_v* 系列函数
 *======================================================================*/

int do_vopen(const char *path, int flags)
{

    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, (char *)path);
    pathname[pathlen] = 0;

    int index;
    int fd = -1;
    index = get_index(pathname);
    if (index == -1)
    {
        kprintf("pathname error! path: %s\n", path);
        return -1;
    }

    fd = vfs_table[index].op->open(pathname, flags); // modified by mingxuan 2020-10-18
    if (fd != -1)
    {
        p_proc_current->task.filp[fd]->dev_index = index;
    }
    else
    {
        kprintf("          error!\n");
    }

    return fd;
}

int do_vclose(int fd)
{
    int index = p_proc_current->task.filp[fd]->dev_index;
    return vfs_table[index].op->close(fd); // modified by mingxuan 2020-10-18
}

int do_vread(int fd, char *buf, int count)
{
    int index = p_proc_current->task.filp[fd]->dev_index;
    return vfs_table[index].op->read(fd, buf, count); // modified by mingxuan 2020-10-18
}

int do_vwrite(int fd, const char *buf, int count)
{
    // modified by mingxuan 2019-5-23
    char s[512];
    int index = p_proc_current->task.filp[fd]->dev_index;
    const char *fsbuf = buf;
    int f_len = count;
    int bytes;
    while (f_len)
    {
        int iobytes = min(512, f_len);
        int i = 0;
        for (i = 0; i < iobytes; i++)
        {
            s[i] = *fsbuf;
            fsbuf++;
        }
        // bytes = device_table[index].op->write(fd,s,iobytes);
        bytes = vfs_table[index].op->write(fd, s, iobytes); // modified by mingxuan 2020-10-18
        if (bytes != iobytes)
        {
            return bytes; // TODO: Maybe problematic
        }
        f_len -= bytes;
    }
    return count;
}

int do_vunlink(const char *path)
{
    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, (char *)path);
    pathname[pathlen] = 0;

    int index;
    index = get_index(pathname);
    if (index == -1)
    {
        kprintf("pathname error!\n");
        return -1;
    }

    // return device_table[index].op->unlink(pathname);
    return vfs_table[index].op->unlink(pathname); // modified by mingxuan 2020-10-18
}

int do_vlseek(int fd, int offset, int whence)
{
    int index = p_proc_current->task.filp[fd]->dev_index;

    // return device_table[index].op->lseek(fd, offset, whence);
    return vfs_table[index].op->lseek(fd, offset, whence); // modified by mingxuan 2020-10-18
}

// int do_vcreate(char *pathname) {
int do_vcreate(char *filepath)
{ // modified by mingxuan 2019-5-17
    // added by mingxuan 2019-5-17
    int state;
    const char *path = filepath;

    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, (char *)path);
    pathname[pathlen] = 0;

    int index;
    index = get_index(pathname);
    if (index == -1)
    {
        kprintf("pathname error! path: %s\n", path);
        return -1;
    }
    state = vfs_table[index].op->create(pathname); // modified by mingxuan 2020-10-18
    if (state == 1)
    {
        kprintf("          create file success!");
    }
    else
    {
        DisErrorInfo(state);
    }
    return state;
}

int do_vdelete(char *path)
{

    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, path);
    pathname[pathlen] = 0;

    int index;
    index = get_index(pathname);
    if (index == -1)
    {
        kprintf("pathname error!\n");
        return -1;
    }
    // return device_table[index].op->delete(pathname);
    return vfs_table[index].op->delete (pathname); // modified by mingxuan 2020-10-18
}
int do_vopendir(char *path)
{
    int state;

    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, path);
    pathname[pathlen] = 0;

    int index;
    index = (int)(pathname[1] - '0');

    for (int j = 0; j <= pathlen - 3; j++)
    {
        pathname[j] = pathname[j + 3];
    }
    state = f_op_table[index].opendir(pathname);
    if (state == 1)
    {
        kprintf("          open dir success!");
    }
    else
    {
        DisErrorInfo(state);
    }
    return state;
}

int do_vcreatedir(char *path)
{
    int state;

    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, path);
    pathname[pathlen] = 0;

    int index;
    index = (int)(pathname[1] - '0');

    for (int j = 0; j <= pathlen - 3; j++)
    {
        pathname[j] = pathname[j + 3];
    }
    state = f_op_table[index].createdir(pathname);
    if (state == 1)
    {
        kprintf("          create dir success!");
    }
    else
    {
        DisErrorInfo(state);
    }
    return state;
}

int do_vdeletedir(char *path)
{
    int state;
    int pathlen = strlen(path);
    char pathname[MAX_PATH];

    strcpy(pathname, path);
    pathname[pathlen] = 0;

    int index;
    index = (int)(pathname[1] - '0');

    for (int j = 0; j <= pathlen - 3; j++)
    {
        pathname[j] = pathname[j + 3];
    }
    state = f_op_table[index].deletedir(pathname);
    if (state == 1)
    {
        kprintf("          delete dir success!");
    }
    else
    {
        DisErrorInfo(state);
    }
    return state;
}