writing to driver failed

[sri]

My driver write routine is not working properly.
As a result, when I do echo "123" > /dev/eater, the process is stopping and
the control goes into an infinite loop.
lsmod showed my driver was in use by 2 processes.
Now if i want to forcefully remove my driver module from kernel, how to do
that?

Below is the write routine:
static int eater_write(struct file *file, const char *buf, size_t lbuf,
loff_t *ppos)
{
        int actual_data_allowed_to_write;
        int data_written;
        int data_to_copy=0;

        printk("requested bytes to write: %d\n", lbuf);

        actual_data_allowed_to_write = MAXSIZE - *ppos;

        printk("allowed bytes to write: %d\n",
actual_data_allowed_to_write);

        if(actual_data_allowed_to_write == 0)
        {
                printk("Device has no space to write. format it\n");
                return(actual_data_allowed_to_write);
        }

        //if available space can accommodate data to write
        if(actual_data_allowed_to_write > lbuf)
                data_to_copy=lbuf;
        //if available space can't accommodate date to write
        if(actual_data_allowed_to_write < lbuf)
                data_to_copy=actual_data_allowed_to_write;

        printk("data_to_copy: %d\n", data_to_copy);

        data_written=copy_from_user(eater_space + *ppos, /* to */ \
                                buf, /* from */ \
                                data_to_copy);

        //update device memory with new position
        *ppos += data_to_copy;
        printk("\nWrote %d bytes\n", data_written);

        return(data_written);
}

Appreciate any help.

/Sri.