kfile.c

/*
** kfile.c
**
** Made by xsyann
** Contact <contact@xsyann.com>
**
** Started on  Fri Mar 14 12:00:51 2014 xsyann
** Last update Fri Apr 18 22:22:37 2014 xsyann
*/

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/unistd.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include "kfile.h"

struct file *kopen(const char *filename, int flags, umode_t mode)
{
        struct file *f = NULL;
        mm_segment_t oldfs;

        oldfs = get_fs();
        set_fs(get_ds());
        f = filp_open(filename, flags, mode);
        set_fs(oldfs);
        if (IS_ERR(f) || (f == NULL))
                return NULL;
        return f;
}

void kclose(struct file *f)
{
        filp_close(f, NULL);
}

ssize_t kread(struct file *file, char __user *buf, size_t count)
{
        mm_segment_t oldfs;
        int ret;

        oldfs = get_fs();
        set_fs(get_ds());

        ret = vfs_read(file, buf, count, &file->f_pos);

        set_fs(oldfs);
        return ret;
}