#ifndef __LINUX__AIO_H
#define __LINUX__AIO_H

#include <linux/list.h>
#include <linux/workqueue.h>
#include <linux/aio_abi.h>
#include <linux/uio.h>
#include <linux/rcupdate.h>

#include <linux/atomic.h>

#define AIO_MAXSEGS		4
#define AIO_KIOGRP_NR_ATOMIC	8

struct kioctx;

#define KIOCB_C_CANCELLED	0x01
#define KIOCB_C_COMPLETE	0x02

#define KIOCB_SYNC_KEY		(~0U)

#define KIF_KICKED		1
#define KIF_CANCELLED		2

#define kiocbTryLock(iocb)	test_and_set_bit(KIF_LOCKED, &(iocb)->ki_flags)
#define kiocbTryKick(iocb)	test_and_set_bit(KIF_KICKED, &(iocb)->ki_flags)

#define kiocbSetLocked(iocb)	set_bit(KIF_LOCKED, &(iocb)->ki_flags)
#define kiocbSetKicked(iocb)	set_bit(KIF_KICKED, &(iocb)->ki_flags)
#define kiocbSetCancelled(iocb)	set_bit(KIF_CANCELLED, &(iocb)->ki_flags)

#define kiocbClearLocked(iocb)	clear_bit(KIF_LOCKED, &(iocb)->ki_flags)
#define kiocbClearKicked(iocb)	clear_bit(KIF_KICKED, &(iocb)->ki_flags)
#define kiocbClearCancelled(iocb)	clear_bit(KIF_CANCELLED, &(iocb)->ki_flags)

#define kiocbIsLocked(iocb)	test_bit(KIF_LOCKED, &(iocb)->ki_flags)
#define kiocbIsKicked(iocb)	test_bit(KIF_KICKED, &(iocb)->ki_flags)
#define kiocbIsCancelled(iocb)	test_bit(KIF_CANCELLED, &(iocb)->ki_flags)

struct kiocb {
	struct list_head	ki_run_list;
	unsigned long		ki_flags;
	int			ki_users;
	unsigned		ki_key;		

	struct file		*ki_filp;
	struct kioctx		*ki_ctx;	
	int			(*ki_cancel)(struct kiocb *, struct io_event *);
	ssize_t			(*ki_retry)(struct kiocb *);
	void			(*ki_dtor)(struct kiocb *);

	union {
		void __user		*user;
		struct task_struct	*tsk;
	} ki_obj;

	__u64			ki_user_data;	
	loff_t			ki_pos;

	void			*private;
	
	unsigned short		ki_opcode;
	size_t			ki_nbytes; 	
	char 			__user *ki_buf;	
	size_t			ki_left; 	
	struct iovec		ki_inline_vec;	
 	struct iovec		*ki_iovec;
 	unsigned long		ki_nr_segs;
 	unsigned long		ki_cur_seg;

	struct list_head	ki_list;	
	struct list_head	ki_batch;	

	struct eventfd_ctx	*ki_eventfd;
};

#define is_sync_kiocb(iocb)	((iocb)->ki_key == KIOCB_SYNC_KEY)
#define init_sync_kiocb(x, filp)			\
	do {						\
		struct task_struct *tsk = current;	\
		(x)->ki_flags = 0;			\
		(x)->ki_users = 1;			\
		(x)->ki_key = KIOCB_SYNC_KEY;		\
		(x)->ki_filp = (filp);			\
		(x)->ki_ctx = NULL;			\
		(x)->ki_cancel = NULL;			\
		(x)->ki_retry = NULL;			\
		(x)->ki_dtor = NULL;			\
		(x)->ki_obj.tsk = tsk;			\
		(x)->ki_user_data = 0;                  \
		(x)->private = NULL;			\
	} while (0)

#define AIO_RING_MAGIC			0xa10a10a1
#define AIO_RING_COMPAT_FEATURES	1
#define AIO_RING_INCOMPAT_FEATURES	0
struct aio_ring {
	unsigned	id;	
	unsigned	nr;	
	unsigned	head;
	unsigned	tail;

	unsigned	magic;
	unsigned	compat_features;
	unsigned	incompat_features;
	unsigned	header_length;	


	struct io_event		io_events[0];
}; 

#define aio_ring_avail(info, ring)	(((ring)->head + (info)->nr - 1 - (ring)->tail) % (info)->nr)

#define AIO_RING_PAGES	8
struct aio_ring_info {
	unsigned long		mmap_base;
	unsigned long		mmap_size;

	struct page		**ring_pages;
	spinlock_t		ring_lock;
	long			nr_pages;

	unsigned		nr, tail;

	struct page		*internal_pages[AIO_RING_PAGES];
};

struct kioctx {
	atomic_t		users;
	int			dead;
	struct mm_struct	*mm;

	
	unsigned long		user_id;
	struct hlist_node	list;

	wait_queue_head_t	wait;

	spinlock_t		ctx_lock;

	int			reqs_active;
	struct list_head	active_reqs;	
	struct list_head	run_list;	

	
	unsigned		max_reqs;

	struct aio_ring_info	ring_info;

	struct delayed_work	wq;

	struct rcu_head		rcu_head;
};

extern unsigned aio_max_size;

#ifdef CONFIG_AIO
extern ssize_t wait_on_sync_kiocb(struct kiocb *iocb);
extern int aio_put_req(struct kiocb *iocb);
extern void kick_iocb(struct kiocb *iocb);
extern int aio_complete(struct kiocb *iocb, long res, long res2);
struct mm_struct;
extern void exit_aio(struct mm_struct *mm);
extern long do_io_submit(aio_context_t ctx_id, long nr,
			 struct iocb __user *__user *iocbpp, bool compat);
#else
static inline ssize_t wait_on_sync_kiocb(struct kiocb *iocb) { return 0; }
static inline int aio_put_req(struct kiocb *iocb) { return 0; }
static inline void kick_iocb(struct kiocb *iocb) { }
static inline int aio_complete(struct kiocb *iocb, long res, long res2) { return 0; }
struct mm_struct;
static inline void exit_aio(struct mm_struct *mm) { }
static inline long do_io_submit(aio_context_t ctx_id, long nr,
				struct iocb __user * __user *iocbpp,
				bool compat) { return 0; }
#endif 

static inline struct kiocb *list_kiocb(struct list_head *h)
{
	return list_entry(h, struct kiocb, ki_list);
}

extern unsigned long aio_nr;
extern unsigned long aio_max_nr;

#endif