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Jens Axboed6b29d72007-06-04 09:59:47 +02001/*
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/*
Jens Axboe2b1ccc02009-05-12 11:11:48 +020014 * Flags passed in from splice/tee/vmsplice
Jens Axboed6b29d72007-06-04 09:59:47 +020015 */
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 */
26struct splice_desc {
27 unsigned int len, total_len; /* current and remaining length */
28 unsigned int flags; /* splice flags */
29 /*
30 * actor() private data
31 */
32 union {
33 void __user *userptr; /* memory to write to */
34 struct file *file; /* file to read/write */
35 void *data; /* cookie */
36 } u;
37 loff_t pos; /* file position */
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +020038 size_t num_spliced; /* number of bytes already spliced */
39 bool need_wakeup; /* need to wake up writer */
Jens Axboed6b29d72007-06-04 09:59:47 +020040};
41
42struct partial_page {
43 unsigned int offset;
44 unsigned int len;
Jens Axboe497f9622007-06-11 12:00:45 +020045 unsigned long private;
Jens Axboed6b29d72007-06-04 09:59:47 +020046};
47
48/*
49 * Passed to splice_to_pipe
50 */
51struct splice_pipe_desc {
52 struct page **pages; /* page map */
53 struct partial_page *partial; /* pages[] may not be contig */
Eric Dumazet047fe362012-06-12 15:24:40 +020054 int nr_pages; /* number of populated pages in map */
55 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
Jens Axboed6b29d72007-06-04 09:59:47 +020056 unsigned int flags; /* splice flags */
57 const struct pipe_buf_operations *ops;/* ops associated with output pipe */
Jens Axboebbdfc2f2007-11-06 23:29:47 -080058 void (*spd_release)(struct splice_pipe_desc *, unsigned int);
Jens Axboed6b29d72007-06-04 09:59:47 +020059};
60
61typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
62 struct splice_desc *);
63typedef int (splice_direct_actor)(struct pipe_inode_info *,
64 struct splice_desc *);
65
66extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
67 loff_t *, size_t, unsigned int,
68 splice_actor *);
69extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
70 struct splice_desc *, splice_actor *);
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +020071extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *,
72 splice_actor *);
73extern int splice_from_pipe_next(struct pipe_inode_info *,
74 struct splice_desc *);
75extern void splice_from_pipe_begin(struct splice_desc *);
76extern void splice_from_pipe_end(struct pipe_inode_info *,
77 struct splice_desc *);
Miklos Szeredi328eaab2009-04-14 19:48:39 +020078extern int pipe_to_file(struct pipe_inode_info *, struct pipe_buffer *,
79 struct splice_desc *);
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +020080
Jens Axboed6b29d72007-06-04 09:59:47 +020081extern ssize_t splice_to_pipe(struct pipe_inode_info *,
82 struct splice_pipe_desc *);
83extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
84 splice_direct_actor *);
85
Jens Axboe35f3d142010-05-20 10:43:18 +020086/*
87 * for dynamic pipe sizing
88 */
Eric Dumazet047fe362012-06-12 15:24:40 +020089extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
90extern void splice_shrink_spd(struct splice_pipe_desc *);
Hugh Dickins708e3502011-07-25 17:12:32 -070091extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
Jens Axboe35f3d142010-05-20 10:43:18 +020092
Hugh Dickins708e3502011-07-25 17:12:32 -070093extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
Jens Axboed6b29d72007-06-04 09:59:47 +020094#endif