#define files_fdtable(files) (rcu_dereference((files)->fdt))
-extern struct kmem_cache *filp_cachep;
-
struct file_operations;
struct vfsmount;
struct dentry;
void put_files_struct(struct files_struct *fs);
void reset_files_struct(struct files_struct *);
int unshare_files(struct files_struct **);
+struct files_struct *dup_fd(struct files_struct *, int *);
extern struct kmem_cache *files_cachep;