[mirror_ubuntu-bionic-kernel.git] / include / linux / splice.h

/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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;
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
d6b29d7c JA	2	/*
	3	* Function declerations and data structures related to the splice
	4	* implementation.
	5	*
	6	* Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com>
	7	*
	8	*/
	9	#ifndef SPLICE_H
	10	#define SPLICE_H
	11
	12	#include <linux/pipe_fs_i.h>
	13
	14	/*
2b1ccc0e	15	* Flags passed in from splice/tee/vmsplice
d6b29d7c JA	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
3d6ea290 AV	24	#define SPLICE_F_ALL (SPLICE_F_MOVE\|SPLICE_F_NONBLOCK\|SPLICE_F_MORE\|SPLICE_F_GIFT)
3d6ea290 AV	25
d6b29d7c JA	26	/*
	27	* Passed to the actors
	28	*/
	29	struct splice_desc {
53e0ee9f XG	30	size_t total_len; /* remaining length */
53e0ee9f XG	31	unsigned int len; /* current length */
d6b29d7c JA	32	unsigned int flags; /* splice flags */
	33	/*
	34	* actor() private data
	35	*/
	36	union {
	37	void __user userptr; / memory to write to */
	38	struct file file; / file to read/write */
	39	void data; / cookie */
	40	} u;
	41	loff_t pos; /* file position */
7995bd28	42	loff_t opos; / sendfile: output position */
b3c2d2dd MS	43	size_t num_spliced; /* number of bytes already spliced */
b3c2d2dd MS	44	bool need_wakeup; /* need to wake up writer */
d6b29d7c JA	45	};
	46
	47	struct partial_page {
	48	unsigned int offset;
	49	unsigned int len;
497f9625	50	unsigned long private;
d6b29d7c JA	51	};
	52
	53	/*
	54	* Passed to splice_to_pipe
	55	*/
	56	struct splice_pipe_desc {
	57	struct page *pages; / page map */
	58	struct partial_page partial; / pages[] may not be contig */
047fe360 ED	59	int nr_pages; /* number of populated pages in map */
047fe360 ED	60	unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
d6b29d7c	61	const struct pipe_buf_operations ops;/ ops associated with output pipe */
bbdfc2f7	62	void (spd_release)(struct splice_pipe_desc , unsigned int);
d6b29d7c JA	63	};
	64
	65	typedef int (splice_actor)(struct pipe_inode_info , struct pipe_buffer ,
	66	struct splice_desc *);
	67	typedef int (splice_direct_actor)(struct pipe_inode_info *,
	68	struct splice_desc *);
	69
	70	extern ssize_t splice_from_pipe(struct pipe_inode_info , struct file ,
	71	loff_t *, size_t, unsigned int,
	72	splice_actor *);
	73	extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
	74	struct splice_desc , splice_actor );
	75	extern ssize_t splice_to_pipe(struct pipe_inode_info *,
	76	struct splice_pipe_desc *);
79fddc4e AV	77	extern ssize_t add_to_pipe(struct pipe_inode_info *,
79fddc4e AV	78	struct pipe_buffer *);
d6b29d7c JA	79	extern ssize_t splice_direct_to_actor(struct file , struct splice_desc ,
	80	splice_direct_actor *);
	81
35f3d14d JA	82	/*
	83	* for dynamic pipe sizing
	84	*/
047fe360 ED	85	extern int splice_grow_spd(const struct pipe_inode_info , struct splice_pipe_desc );
047fe360 ED	86	extern void splice_shrink_spd(struct splice_pipe_desc *);
35f3d14d	87
708e3508	88	extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
241699cd	89	extern const struct pipe_buf_operations default_pipe_buf_ops;
d6b29d7c	90	#endif