[mirror_ubuntu-artful-kernel.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 */

#define SPLICE_F_ALL (SPLICE_F_MOVE|SPLICE_F_NONBLOCK|SPLICE_F_MORE|SPLICE_F_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 */
	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 add_to_pipe(struct pipe_inode_info *,
			      struct pipe_buffer *);
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 const struct pipe_buf_operations page_cache_pipe_buf_ops;
extern const struct pipe_buf_operations default_pipe_buf_ops;

extern long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
			   loff_t *ppos, size_t len, unsigned int flags);
extern long do_splice_to(struct file *in, loff_t *ppos,
			 struct pipe_inode_info *pipe, size_t len,
			 unsigned int flags);
#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
3d6ea290 AV	23	#define SPLICE_F_ALL (SPLICE_F_MOVE\|SPLICE_F_NONBLOCK\|SPLICE_F_MORE\|SPLICE_F_GIFT)
3d6ea290 AV	24
d6b29d7c JA	25	/*
	26	* Passed to the actors
	27	*/
	28	struct splice_desc {
53e0ee9f XG	29	size_t total_len; /* remaining length */
53e0ee9f XG	30	unsigned int len; /* current length */
d6b29d7c JA	31	unsigned int flags; /* splice flags */
	32	/*
	33	* actor() private data
	34	*/
	35	union {
	36	void __user userptr; / memory to write to */
	37	struct file file; / file to read/write */
	38	void data; / cookie */
	39	} u;
	40	loff_t pos; /* file position */
7995bd28	41	loff_t opos; / sendfile: output position */
b3c2d2dd MS	42	size_t num_spliced; /* number of bytes already spliced */
b3c2d2dd MS	43	bool need_wakeup; /* need to wake up writer */
d6b29d7c JA	44	};
	45
	46	struct partial_page {
	47	unsigned int offset;
	48	unsigned int len;
497f9625	49	unsigned long private;
d6b29d7c JA	50	};
	51
	52	/*
	53	* Passed to splice_to_pipe
	54	*/
	55	struct splice_pipe_desc {
	56	struct page *pages; / page map */
	57	struct partial_page partial; / pages[] may not be contig */
047fe360 ED	58	int nr_pages; /* number of populated pages in map */
047fe360 ED	59	unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
d6b29d7c	60	const struct pipe_buf_operations ops;/ ops associated with output pipe */
bbdfc2f7	61	void (spd_release)(struct splice_pipe_desc , unsigned int);
d6b29d7c JA	62	};
	63
	64	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	65	struct splice_desc *);
	66	typedef int (splice_direct_actor)(struct pipe_inode_info *,
	67	struct splice_desc *);
	68
	69	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	70	loff_t *, size_t, unsigned int,
	71	splice_actor *);
	72	extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
	73	struct splice_desc , splice_actor );
	74	extern ssize_t splice_to_pipe(struct pipe_inode_info *,
	75	struct splice_pipe_desc *);
79fddc4e AV	76	extern ssize_t add_to_pipe(struct pipe_inode_info *,
79fddc4e AV	77	struct pipe_buffer *);
d6b29d7c JA	78	extern ssize_t splice_direct_to_actor(struct file , struct splice_desc ,
	79	splice_direct_actor *);
	80
35f3d14d JA	81	/*
	82	* for dynamic pipe sizing
	83	*/
047fe360 ED	84	extern int splice_grow_spd(const struct pipe_inode_info , struct splice_pipe_desc );
047fe360 ED	85	extern void splice_shrink_spd(struct splice_pipe_desc *);
35f3d14d	86
708e3508	87	extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
241699cd	88	extern const struct pipe_buf_operations default_pipe_buf_ops;
b6450630 SF	89
	90	extern long do_splice_from(struct pipe_inode_info pipe, struct file out,
	91	loff_t *ppos, size_t len, unsigned int flags);
	92	extern long do_splice_to(struct file in, loff_t ppos,
	93	struct pipe_inode_info *pipe, size_t len,
	94	unsigned int flags);
d6b29d7c	95	#endif