-int lustre_fread(struct file *file, void *buf, int len, loff_t *off);
-int lustre_fwrite(struct file *file, const void *buf, int len, loff_t *off);
-int lustre_fsync(struct file *file);
-long l_readdir(struct file * file, cfs_list_t *dentry_list);
-int l_notify_change(struct vfsmount *mnt, struct dentry *dchild,
- struct iattr *newattrs);
-int simple_truncate(struct dentry *dir, struct vfsmount *mnt,
- char *name, loff_t length);