extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);
extern struct vm_struct *get_vm_area_node(unsigned long size,
unsigned long flags, int node,
gfp_t gfp_mask);
extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
unsigned long start, unsigned long end);
extern struct vm_struct *get_vm_area_node(unsigned long size,
unsigned long flags, int node,
gfp_t gfp_mask);