[linux-2.6-block.git] / include / linux / splice.h

/*
 * 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>

/*
 * splice is tied to pipes as a transport (at least for now), so we'll just
 * add the splice flags here.
 */
#define SPLICE_F_MOVE	(0x01)	/* move pages instead of copying */
#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
				 /* we may still block on the fd we splice */
				 /* from/to, of course */
#define SPLICE_F_MORE	(0x04)	/* expect more data */
#define SPLICE_F_GIFT	(0x08)	/* pages passed in are a gift */

/*
 * Passed to the actors
 */
struct splice_desc {
	unsigned int len, total_len;	/* current and remaining length */
	unsigned int flags;		/* splice flags */
	/*
	 * actor() private data
	 */
	union {
		void __user *userptr;	/* memory to write to */
		struct file *file;	/* file to read/write */
		void *data;		/* cookie */
	} u;
	loff_t pos;			/* file position */
};

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

/*
 * Passed to splice_to_pipe
 */
struct splice_pipe_desc {
	struct page **pages;		/* page map */
	struct partial_page *partial;	/* pages[] may not be contig */
	int nr_pages;			/* number of pages in map */
	unsigned int flags;		/* splice flags */
	const struct pipe_buf_operations *ops;/* ops associated with output pipe */
};

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 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 *);

#endif
Commit	Line	Data
d6b29d7c JA	1	/*
	2	* Function declerations and data structures related to the splice
	3	* implementation.
	4	*
	5	* Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
	6	*
	7	*/
	8	#ifndef SPLICE_H
	9	#define SPLICE_H
	10
	11	#include <linux/pipe_fs_i.h>
	12
	13	/*
	14	* splice is tied to pipes as a transport (at least for now), so we'll just
	15	* add the splice flags here.
	16	*/
	17	#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
	18	#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
	19	/* we may still block on the fd we splice */
	20	/* from/to, of course */
	21	#define SPLICE_F_MORE (0x04) /* expect more data */
	22	#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
	23
	24	/*
	25	* Passed to the actors
	26	*/
	27	struct splice_desc {
	28	unsigned int len, total_len; /* current and remaining length */
	29	unsigned int flags; /* splice flags */
	30	/*
	31	* actor() private data
	32	*/
	33	union {
	34	void __user userptr; / memory to write to */
	35	struct file file; / file to read/write */
	36	void data; / cookie */
	37	} u;
	38	loff_t pos; /* file position */
	39	};
	40
	41	struct partial_page {
	42	unsigned int offset;
	43	unsigned int len;
497f9625	44	unsigned long private;
d6b29d7c JA	45	};
	46
	47	/*
	48	* Passed to splice_to_pipe
	49	*/
	50	struct splice_pipe_desc {
	51	struct page *pages; / page map */
	52	struct partial_page partial; / pages[] may not be contig */
	53	int nr_pages; /* number of pages in map */
	54	unsigned int flags; /* splice flags */
	55	const struct pipe_buf_operations ops;/ ops associated with output pipe */
	56	};
	57
	58	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	59	struct splice_desc *);
	60	typedef int (splice_direct_actor)(struct pipe_inode_info *,
	61	struct splice_desc *);
	62
	63	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	64	loff_t *, size_t, unsigned int,
	65	splice_actor *);
	66	extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
	67	struct splice_desc , splice_actor );
	68	extern ssize_t splice_to_pipe(struct pipe_inode_info *,
	69	struct splice_pipe_desc *);
	70	extern ssize_t splice_direct_to_actor(struct file , struct splice_desc ,
	71	splice_direct_actor *);
	72
	73	#endif