extern int mount_snapshot(struct volume *v);
extern int mount_overlay(struct volume *v);
-extern int mount_move(char *oldroot, char *newroot, char *dir);
+extern int mount_move(const char *oldroot, const char *newroot, const char *dir);
extern int pivot(char *new, char *old);
extern int fopivot(char *rw_root, char *ro_root);
extern int ramoverlay(void);