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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 {
Xiao Guangrong53e0ee92014-01-27 17:07:12 -080027 size_t total_len; /* remaining length */
28 unsigned int len; /* current length */
Jens Axboed6b29d72007-06-04 09:59:47 +020029 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 */
Al Viro7995bd22013-06-20 18:58:36 +040039 loff_t *opos; /* sendfile: output position */
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +020040 size_t num_spliced; /* number of bytes already spliced */
41 bool need_wakeup; /* need to wake up writer */
Jens Axboed6b29d72007-06-04 09:59:47 +020042};
43
44struct partial_page {
45 unsigned int offset;
46 unsigned int len;
Jens Axboe497f9622007-06-11 12:00:45 +020047 unsigned long private;
Jens Axboed6b29d72007-06-04 09:59:47 +020048};
49
50/*
51 * Passed to splice_to_pipe
52 */
53struct splice_pipe_desc {
54 struct page **pages; /* page map */
55 struct partial_page *partial; /* pages[] may not be contig */
Eric Dumazet047fe362012-06-12 15:24:40 +020056 int nr_pages; /* number of populated pages in map */
57 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
Jens Axboed6b29d72007-06-04 09:59:47 +020058 unsigned int flags; /* splice flags */
59 const struct pipe_buf_operations *ops;/* ops associated with output pipe */
Jens Axboebbdfc2f2007-11-06 23:29:47 -080060 void (*spd_release)(struct splice_pipe_desc *, unsigned int);
Jens Axboed6b29d72007-06-04 09:59:47 +020061};
62
63typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
64 struct splice_desc *);
65typedef int (splice_direct_actor)(struct pipe_inode_info *,
66 struct splice_desc *);
67
68extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
69 loff_t *, size_t, unsigned int,
70 splice_actor *);
71extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
72 struct splice_desc *, splice_actor *);
Jens Axboed6b29d72007-06-04 09:59:47 +020073extern ssize_t splice_to_pipe(struct pipe_inode_info *,
74 struct splice_pipe_desc *);
Al Viro79fddc42016-09-17 22:38:20 -040075extern ssize_t add_to_pipe(struct pipe_inode_info *,
76 struct pipe_buffer *);
Jens Axboed6b29d72007-06-04 09:59:47 +020077extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
78 splice_direct_actor *);
79
Jens Axboe35f3d142010-05-20 10:43:18 +020080/*
81 * for dynamic pipe sizing
82 */
Eric Dumazet047fe362012-06-12 15:24:40 +020083extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
84extern void splice_shrink_spd(struct splice_pipe_desc *);
Hugh Dickins708e3502011-07-25 17:12:32 -070085extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
Jens Axboe35f3d142010-05-20 10:43:18 +020086
Hugh Dickins708e3502011-07-25 17:12:32 -070087extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
Al Viro241699c2016-09-22 16:33:12 -040088extern const struct pipe_buf_operations default_pipe_buf_ops;
Jens Axboed6b29d72007-06-04 09:59:47 +020089#endif