[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>

/*
 * Flags passed in from splice/tee/vmsplice
 */
#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 {
	size_t total_len;		/* remaining length */
	unsigned int len;		/* current 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 */
	loff_t *opos;			/* sendfile: output position */
	size_t num_spliced;		/* number of bytes already spliced */
	bool need_wakeup;		/* need to wake up writer */
};

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 populated pages in map */
	unsigned int nr_pages_max;	/* pages[] & partial[] arrays size */
	unsigned int flags;		/* splice flags */
	const struct pipe_buf_operations *ops;/* ops associated with output pipe */
	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 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 *);

/*
 * for dynamic pipe sizing
 */
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
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	/*
2b1ccc0e	14	* Flags passed in from splice/tee/vmsplice
d6b29d7c JA	15	*/
	16	#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
	17	#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
	18	/* we may still block on the fd we splice */
	19	/* from/to, of course */
	20	#define SPLICE_F_MORE (0x04) /* expect more data */
	21	#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
	22
	23	/*
	24	* Passed to the actors
	25	*/
	26	struct splice_desc {
53e0ee9f XG	27	size_t total_len; /* remaining length */
53e0ee9f XG	28	unsigned int len; /* current length */
d6b29d7c JA	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 */
7995bd28	39	loff_t opos; / sendfile: output position */
b3c2d2dd MS	40	size_t num_spliced; /* number of bytes already spliced */
b3c2d2dd MS	41	bool need_wakeup; /* need to wake up writer */
d6b29d7c JA	42	};
	43
	44	struct partial_page {
	45	unsigned int offset;
	46	unsigned int len;
497f9625	47	unsigned long private;
d6b29d7c JA	48	};
	49
	50	/*
	51	* Passed to splice_to_pipe
	52	*/
	53	struct splice_pipe_desc {
	54	struct page *pages; / page map */
	55	struct partial_page partial; / pages[] may not be contig */
047fe360 ED	56	int nr_pages; /* number of populated pages in map */
047fe360 ED	57	unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
d6b29d7c JA	58	unsigned int flags; /* splice flags */
d6b29d7c JA	59	const struct pipe_buf_operations ops;/ ops associated with output pipe */
bbdfc2f7	60	void (spd_release)(struct splice_pipe_desc , unsigned int);
d6b29d7c JA	61	};
	62
	63	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	64	struct splice_desc *);
	65	typedef int (splice_direct_actor)(struct pipe_inode_info *,
	66	struct splice_desc *);
	67
	68	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	69	loff_t *, size_t, unsigned int,
	70	splice_actor *);
	71	extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
	72	struct splice_desc , splice_actor );
	73	extern ssize_t splice_to_pipe(struct pipe_inode_info *,
	74	struct splice_pipe_desc *);
	75	extern ssize_t splice_direct_to_actor(struct file , struct splice_desc ,
	76	splice_direct_actor *);
	77
35f3d14d JA	78	/*
	79	* for dynamic pipe sizing
	80	*/
047fe360 ED	81	extern int splice_grow_spd(const struct pipe_inode_info , struct splice_pipe_desc );
047fe360 ED	82	extern void splice_shrink_spd(struct splice_pipe_desc *);
708e3508	83	extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
35f3d14d	84
708e3508	85	extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
d6b29d7c	86	#endif