blob: 32865004751c7cc375a403d1f68f634daa287ec9 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
#ifndef _LINUX_PIPE_FS_I_H
#define _LINUX_PIPE_FS_I_H
#define PIPEFS_MAGIC 0x50495045
#define PIPE_BUFFERS (16)
struct pipe_buffer {
struct page *page;
unsigned int offset, len;
struct pipe_buf_operations *ops;
};
struct pipe_buf_operations {
int can_merge;
void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *);
void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
};
struct pipe_inode_info {
wait_queue_head_t wait;
unsigned int nrbufs, curbuf;
struct pipe_buffer bufs[PIPE_BUFFERS];
struct page *tmp_page;
unsigned int start;
unsigned int readers;
unsigned int writers;
unsigned int waiting_writers;
unsigned int r_counter;
unsigned int w_counter;
struct fasync_struct *fasync_readers;
struct fasync_struct *fasync_writers;
};
/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
#define PIPE_SIZE PAGE_SIZE
#define PIPE_MUTEX(inode) (&(inode).i_mutex)
#define PIPE_WAIT(inode) (&(inode).i_pipe->wait)
#define PIPE_READERS(inode) ((inode).i_pipe->readers)
#define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
#define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers)
#define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter)
#define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter)
#define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers))
#define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers))
/* Drop the inode semaphore and wait for a pipe event, atomically */
void pipe_wait(struct inode * inode);
struct inode* pipe_new(struct inode* inode);
void free_pipe_info(struct inode* inode);
/*
* splice is tied to pipes as a transport (at least for now), so we'll just
* add the splice flags here.
*/
#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
/* we may still block on the fd we splice */
/* from/to, of course */
#endif
|
