1/* SPDX-License-Identifier: GPL-2.0 */
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/*
15 * Flags passed in from splice/tee/vmsplice
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
24#define SPLICE_F_ALL (SPLICE_F_MOVE|SPLICE_F_NONBLOCK|SPLICE_F_MORE|SPLICE_F_GIFT)
25
26/*
27 * Passed to the actors
28 */
29struct splice_desc {
30 size_t total_len; /* remaining length */
31 unsigned int len; /* current length */
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 void (*splice_eof)(struct splice_desc *sd); /* Unexpected EOF handler */
42 loff_t pos; /* file position */
43 loff_t *opos; /* sendfile: output position */
44 size_t num_spliced; /* number of bytes already spliced */
45 bool need_wakeup; /* need to wake up writer */
46};
47
48struct partial_page {
49 unsigned int offset;
50 unsigned int len;
51 unsigned long private;
52};
53
54/*
55 * Passed to splice_to_pipe
56 */
57struct splice_pipe_desc {
58 struct page **pages; /* page map */
59 struct partial_page *partial; /* pages[] may not be contig */
60 int nr_pages; /* number of populated pages in map */
61 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */
62 const struct pipe_buf_operations *ops;/* ops associated with output pipe */
63 void (*spd_release)(struct splice_pipe_desc *, unsigned int);
64};
65
66typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
67 struct splice_desc *);
68typedef int (splice_direct_actor)(struct pipe_inode_info *,
69 struct splice_desc *);
70
71ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out,
72 loff_t *ppos, size_t len, unsigned int flags,
73 splice_actor *actor);
74ssize_t __splice_from_pipe(struct pipe_inode_info *pipe,
75 struct splice_desc *sd, splice_actor *actor);
76ssize_t splice_to_pipe(struct pipe_inode_info *pipe,
77 struct splice_pipe_desc *spd);
78ssize_t add_to_pipe(struct pipe_inode_info *pipe, struct pipe_buffer *buf);
79ssize_t vfs_splice_read(struct file *in, loff_t *ppos,
80 struct pipe_inode_info *pipe, size_t len,
81 unsigned int flags);
82ssize_t splice_direct_to_actor(struct file *file, struct splice_desc *sd,
83 splice_direct_actor *actor);
84ssize_t do_splice(struct file *in, loff_t *off_in, struct file *out,
85 loff_t *off_out, size_t len, unsigned int flags);
86ssize_t do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
87 loff_t *opos, size_t len, unsigned int flags);
88ssize_t splice_file_range(struct file *in, loff_t *ppos, struct file *out,
89 loff_t *opos, size_t len);
90
91static inline long splice_copy_file_range(struct file *in, loff_t pos_in,
92 struct file *out, loff_t pos_out,
93 size_t len)
94{
95 return splice_file_range(in, ppos: &pos_in, out, opos: &pos_out, len);
96}
97
98ssize_t do_tee(struct file *in, struct file *out, size_t len,
99 unsigned int flags);
100ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out,
101 loff_t *ppos, size_t len, unsigned int flags);
102
103/*
104 * for dynamic pipe sizing
105 */
106extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
107extern void splice_shrink_spd(struct splice_pipe_desc *);
108
109extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
110extern const struct pipe_buf_operations default_pipe_buf_ops;
111#endif
112

source code of linux/include/linux/splice.h

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