Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
[linux-2.6-microblaze.git] / include / linux / splice.h
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         loff_t pos;                     /* file position */
42         loff_t *opos;                   /* sendfile: output position */
43         size_t num_spliced;             /* number of bytes already spliced */
44         bool need_wakeup;               /* need to wake up writer */
45 };
46
47 struct partial_page {
48         unsigned int offset;
49         unsigned int len;
50         unsigned long private;
51 };
52
53 /*
54  * Passed to splice_to_pipe
55  */
56 struct splice_pipe_desc {
57         struct page **pages;            /* page map */
58         struct partial_page *partial;   /* pages[] may not be contig */
59         int nr_pages;                   /* number of populated pages in map */
60         unsigned int nr_pages_max;      /* pages[] & partial[] arrays size */
61         const struct pipe_buf_operations *ops;/* ops associated with output pipe */
62         void (*spd_release)(struct splice_pipe_desc *, unsigned int);
63 };
64
65 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
66                            struct splice_desc *);
67 typedef int (splice_direct_actor)(struct pipe_inode_info *,
68                                   struct splice_desc *);
69
70 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
71                                 loff_t *, size_t, unsigned int,
72                                 splice_actor *);
73 extern ssize_t __splice_from_pipe(struct pipe_inode_info *,
74                                   struct splice_desc *, splice_actor *);
75 extern ssize_t splice_to_pipe(struct pipe_inode_info *,
76                               struct splice_pipe_desc *);
77 extern ssize_t add_to_pipe(struct pipe_inode_info *,
78                               struct pipe_buffer *);
79 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
80                                       splice_direct_actor *);
81 extern long do_splice(struct file *in, loff_t *off_in,
82                       struct file *out, loff_t *off_out,
83                       size_t len, unsigned int flags);
84
85 extern long do_tee(struct file *in, struct file *out, size_t len,
86                    unsigned int flags);
87
88 /*
89  * for dynamic pipe sizing
90  */
91 extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *);
92 extern void splice_shrink_spd(struct splice_pipe_desc *);
93
94 extern const struct pipe_buf_operations page_cache_pipe_buf_ops;
95 extern const struct pipe_buf_operations default_pipe_buf_ops;
96 #endif