I wrote a simple module. Why is the kernel function not running?

After writing a simple module, why is the kernel function not running-Linux general technology-Linux programming and kernel information? For details, refer to the following. # If defined (CONFIG_SMP)
# Define _ SMP __
# Endif

# If defined (CONFIG_MODVERSIONS)
# Define MODVERSIONS
# Include
# Endif

# Include
# Include
# Include
# Include

# Define BUFLEN 50

MODULE_LICENSE ("GPL ");
Int errno;
# Define _ kernel_syscils __
# Include


Int init_module (void)
{
Int fd, n;
Char * buffer = NULL;
Struct file * file = filp_open ("/usr/src/Hello", O_RDWR | O_CREAT, 0666 );
If (file-> f_op-> write)
{
Printk (KERN_DEBUG "AAAAA! \ N ");
File-> f_op-> write (file, "11111", 5, & file-> f_pos );
}
Return 0;
}
Void cleanup_module (void)
{
Printk (KERN_DEBUG "Sophia: Good-bye, kernel! \ N ");
}

Compile:
Gcc-D__KERNEL _-I/usr/src/linux-2.4.20-8/include/-DMODULE-Wall-O2-c test. c-o test. o
No error reported
Insmod test. o can be correctly loaded and the file "Hello" can be created.
However, you can view the log through dmesg | tail and find
If (file-> f_op-> write)
{
Printk (KERN_DEBUG "AAAAA! \ N ");
File-> f_op-> write (file, "11111", 5, & file-> f_pos );
} Not executed
I don't know why I didn't write 11111 to the file. Please give me some guidance!