内核读写文件以及睡眠的test

   刚测试了下SLEEP_MILLI_SEC在内核睡眠... 二是内核不用fclose, tail -f就可以看到刚写入的文件,代码比较粗糙，还望自己琢磨下^_^

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <asm/uaccess.h>
#include <linux/mm.h>

MODULE_AUTHOR("[e-mail].");
MODULE_DESCRIPTION("Kernel study and test.");

struct file *filp;
mm_segment_t fs;
  
void SLEEP_MILLI_SEC(int nMilliSec)
{
 long timeout = (nMilliSec) * 100 / 1000;
  while(timeout > 0)
   {
     timeout = schedule_timeout(timeout);
   }
}


#if 0
void fileread(const char * filename)
{
  struct file *filp;
  struct inode *inode;
  mm_segment_t fs;
  off_t fsize;
  char *buf;
  unsigned long magic;
  printk("<1>start....\n");
  filp=filp_open(filename,O_RDONLY,0);
  inode=filp->f_dentry->d_inode;
  
  magic=inode->i_sb->s_magic;
  printk("<1>file system magic:%li \n",magic);
  printk("<1>super blocksize:%li \n",inode->i_sb->s_blocksize);
  printk("<1>inode %li \n",inode->i_ino);
  fsize=inode->i_size;
  printk("<1>file size:%i \n",(int)fsize);
  buf=(char *) kmalloc(fsize+1,GFP_ATOMIC);

  fs=get_fs();
  set_fs(KERNEL_DS);
  filp->f_op->read(filp,buf,fsize,&(filp->f_pos));
  set_fs(fs);

  buf[fsize]='\0';
  printk("<1>The File Content is:\n");
  printk("<1>%s",buf);


  filp_close(filp,NULL);
}
#endif

void filewrite(char* filename, char* data)
{
  fs=get_fs();
  set_fs(KERNEL_DS);
  filp->f_op->write(filp, data, strlen(data),&filp->f_pos);
  set_fs(fs);
}

void test_write(char* filename)
{
 int i;
 char data[20];
  filp = filp_open(filename, O_RDWR|O_APPEND, 0644);
  if(IS_ERR(filp))
   {
    printk("open error...\n");
    return;
   }


 for(i=0;i<10;i++)
 {
     sprintf(data, "%s, %d\n", "kernel write test", i);
     filewrite(filename, data);
  SLEEP_MILLI_SEC(1000);
 }
}
int init_module()
{
  char *filename="/root/log";

  printk("<1>Read File from Kernel.\n");
 // fileread(filename);

  test_write(filename);
  return 0;
}

void cleanup_module()
{
    filp_close(filp,NULL);
  printk("<1>Good,Bye!\n");
}