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 | */ |
29 | struct 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 | |
48 | struct partial_page { |
49 | unsigned int offset; |
50 | unsigned int len; |
51 | unsigned long private; |
52 | }; |
53 | |
54 | /* |
55 | * Passed to splice_to_pipe |
56 | */ |
57 | struct 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 | |
66 | typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, |
67 | struct splice_desc *); |
68 | typedef int (splice_direct_actor)(struct pipe_inode_info *, |
69 | struct splice_desc *); |
70 | |
71 | extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, |
72 | loff_t *, size_t, unsigned int, |
73 | splice_actor *); |
74 | extern ssize_t __splice_from_pipe(struct pipe_inode_info *, |
75 | struct splice_desc *, splice_actor *); |
76 | extern ssize_t splice_to_pipe(struct pipe_inode_info *, |
77 | struct splice_pipe_desc *); |
78 | extern ssize_t add_to_pipe(struct pipe_inode_info *, |
79 | struct pipe_buffer *); |
80 | long vfs_splice_read(struct file *in, loff_t *ppos, |
81 | struct pipe_inode_info *pipe, size_t len, |
82 | unsigned int flags); |
83 | extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, |
84 | splice_direct_actor *); |
85 | extern long do_splice(struct file *in, loff_t *off_in, |
86 | struct file *out, loff_t *off_out, |
87 | size_t len, unsigned int flags); |
88 | |
89 | extern long do_tee(struct file *in, struct file *out, size_t len, |
90 | unsigned int flags); |
91 | extern ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out, |
92 | loff_t *ppos, size_t len, unsigned int flags); |
93 | |
94 | /* |
95 | * for dynamic pipe sizing |
96 | */ |
97 | extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); |
98 | extern void splice_shrink_spd(struct splice_pipe_desc *); |
99 | |
100 | extern const struct pipe_buf_operations page_cache_pipe_buf_ops; |
101 | extern const struct pipe_buf_operations default_pipe_buf_ops; |
102 | #endif |
103 | |