如何在Linux核心中寫檔案

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/fs.h>

#include <linux/string.h>

#include <linux/mm.h>

#include <linux/syscalls.h>

#include <asm/unistd.h>

#include <asm/uaccess.h>

#define MY_FILE "/root/LogFile"

char buf[128];

struct file *file = NULL;

static int __init init(void)

{

        mm_segment_t old_fs;

        printk("Hello, I'm the module that intends to write messages to file./n");

        if(file == NULL)

                file = filp_open(MY_FILE, O_RDWR | O_APPEND | O_CREAT, 0644);

        if (IS_ERR(file)) {

                printk("error occured while opening file %s, exiting.../n", MY_FILE);

                return 0;

        }

        sprintf(buf,"%s", "The Messages.");

        old_fs = get_fs();

        set_fs(KERNEL_DS);

        file->f_op->write(file, (char *)buf, sizeof(buf), &file->f_pos);

        set_fs(old_fs);

        return 0;

}

static void __exit fini(void)

{

        if(file != NULL)

                filp_close(file, NULL);

}

module_init(init);

module_exit(fini);

MODULE_LICENSE("GPL");