/*
 * Function declerations and data structures related to the splice
 * implementation.
 *
 * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
 *
 */
#ifndef SPLICE_H
#define SPLICE_H

#include <linux/pipe_fs_i.h>

#define SPLICE_F_MOVE	(0x01)	
#define SPLICE_F_NONBLOCK (0x02) 
				 
				 
#define SPLICE_F_MORE	(0x04)	
#define SPLICE_F_GIFT	(0x08)	

struct splice_desc {
	unsigned int len, total_len;	
	unsigned int flags;		
	union {
		void __user *userptr;	
		struct file *file;	
		void *data;		
	} u;
	loff_t pos;			
	size_t num_spliced;		
	bool need_wakeup;		
};

struct partial_page {
	unsigned int offset;
	unsigned int len;
	unsigned long private;
};

struct splice_pipe_desc {
	struct page **pages;		
	struct partial_page *partial;	
	int nr_pages;			
	unsigned int nr_pages_max;	
	unsigned int flags;		
	const struct pipe_buf_operations *ops;
	void (*spd_release)(struct splice_pipe_desc *, unsigned int);
};

typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
			   struct splice_desc *);
typedef int (splice_direct_actor)(struct pipe_inode_info *,
				  struct splice_desc *);

extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
				loff_t *, size_t, unsigned int,
				splice_actor *);
extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
				  struct splice_desc *, splice_actor *);
extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *,
				 splice_actor *);
extern int splice_from_pipe_next(struct pipe_inode_info *,
				 struct splice_desc *);
extern void splice_from_pipe_begin(struct splice_desc *);
extern void splice_from_pipe_end(struct pipe_inode_info *,
				 struct splice_desc *);
extern int pipe_to_file(struct pipe_inode_info *, struct pipe_buffer *,
			struct splice_desc *);

extern ssize_t splice_to_pipe(struct pipe_inode_info *,
			      struct splice_pipe_desc *);
extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
				      splice_direct_actor *);

extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
extern void splice_shrink_spd(struct splice_pipe_desc *);
extern void spd_release_page(struct splice_pipe_desc *, unsigned int);

extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
#endif