Blame view

kernel/linux-imx6_3.14.28/include/linux/splice.h 3.03 KB
6b13f685e   김민수   BSP 최초 추가
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
  /*
   * 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 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 *);
  
  /*
   * 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