may_umount
param->askumount.may_umount = 0;
if (may_umount(fp->f_path.mnt))
param->askumount.may_umount = 1;
if (may_umount(mnt))
EXPORT_SYMBOL(may_umount);
extern int may_umount(struct vfsmount *);
__u32 may_umount;