Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.9 / b75e2e3d2824803f1e8b620e99cf5f228c58a200 / . / include / linux / splice.h
blob: 74575cbf2d6f579c317fec5f1f16e9d3793fab03 [file] [log] [blame]
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]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/*
Jens Axboe2b1ccc02009-05-12 11:11:48 +0200[diff] [blame]14 * Flags passed in from splice/tee/vmsplice
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]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
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 */
Al Viro7995bd22013-06-20 18:58:36 +0400[diff] [blame]38 loff_t *opos; /* sendfile: output position */
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +0200[diff] [blame]39 size_t num_spliced; /* number of bytes already spliced */
40 bool need_wakeup; /* need to wake up writer */
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]41};
42
43struct partial_page {
44 unsigned int offset;
45 unsigned int len;
Jens Axboe497f9622007-06-11 12:00:45 +0200[diff] [blame]46 unsigned long private;
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]47};
48
49/*
50 * Passed to splice_to_pipe
51 */
52struct splice_pipe_desc {
53 struct page **pages; /* page map */
54 struct partial_page *partial; /* pages[] may not be contig */
Eric Dumazet047fe362012-06-12 15:24:40 +0200[diff] [blame]55 int nr_pages; /* number of populated pages in map */
56 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]57 unsigned int flags; /* splice flags */
58 const struct pipe_buf_operations *ops;/* ops associated with output pipe */
Jens Axboebbdfc2f2007-11-06 23:29:47 -0800[diff] [blame]59 void (*spd_release)(struct splice_pipe_desc *, unsigned int);
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]60};
61
62typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
63 struct splice_desc *);
64typedef int (splice_direct_actor)(struct pipe_inode_info *,
65 struct splice_desc *);
66
67extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
68 loff_t *, size_t, unsigned int,
69 splice_actor *);
70extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
71 struct splice_desc *, splice_actor *);
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +0200[diff] [blame]72extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *,
73 splice_actor *);
74extern int splice_from_pipe_next(struct pipe_inode_info *,
75 struct splice_desc *);
76extern void splice_from_pipe_begin(struct splice_desc *);
77extern void splice_from_pipe_end(struct pipe_inode_info *,
78 struct splice_desc *);
Miklos Szeredi328eaab2009-04-14 19:48:39 +0200[diff] [blame]79extern int pipe_to_file(struct pipe_inode_info *, struct pipe_buffer *,
80 struct splice_desc *);
Miklos Szeredib3c2d2d2009-04-14 19:48:36 +0200[diff] [blame]81
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]82extern ssize_t splice_to_pipe(struct pipe_inode_info *,
83 struct splice_pipe_desc *);
84extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
85 splice_direct_actor *);
86
Jens Axboe35f3d142010-05-20 10:43:18 +0200[diff] [blame]87/*
88 * for dynamic pipe sizing
89 */
Eric Dumazet047fe362012-06-12 15:24:40 +0200[diff] [blame]90extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
91extern void splice_shrink_spd(struct splice_pipe_desc *);
Hugh Dickins708e3502011-07-25 17:12:32 -0700[diff] [blame]92extern void spd_release_page(struct splice_pipe_desc *, unsigned int);
Jens Axboe35f3d142010-05-20 10:43:18 +0200[diff] [blame]93
Hugh Dickins708e3502011-07-25 17:12:32 -0700[diff] [blame]94extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
Jens Axboed6b29d72007-06-04 09:59:47 +0200[diff] [blame]95#endif