Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1#ifndef _LINUX_PIPE_FS_I_H
2#define _LINUX_PIPE_FS_I_H
3
4#define PIPEFS_MAGIC 0x50495045
5
6#define PIPE_BUFFERS (16)
7
8struct pipe_buffer {
9 struct page *page;
10 unsigned int offset, len;
11 struct pipe_buf_operations *ops;
12};
13
14struct pipe_buf_operations {
15 int can_merge;
16 void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *);
17 void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
18 void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
19};
20
21struct pipe_inode_info {
22 wait_queue_head_t wait;
23 unsigned int nrbufs, curbuf;
24 struct pipe_buffer bufs[PIPE_BUFFERS];
25 struct page *tmp_page;
26 unsigned int start;
27 unsigned int readers;
28 unsigned int writers;
29 unsigned int waiting_writers;
30 unsigned int r_counter;
31 unsigned int w_counter;
32 struct fasync_struct *fasync_readers;
33 struct fasync_struct *fasync_writers;
34};
35
36/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
37 memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
38#define PIPE_SIZE PAGE_SIZE
39
40#define PIPE_SEM(inode) (&(inode).i_sem)
41#define PIPE_WAIT(inode) (&(inode).i_pipe->wait)
42#define PIPE_BASE(inode) ((inode).i_pipe->base)
43#define PIPE_START(inode) ((inode).i_pipe->start)
44#define PIPE_LEN(inode) ((inode).i_pipe->len)
45#define PIPE_READERS(inode) ((inode).i_pipe->readers)
46#define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
47#define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers)
48#define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter)
49#define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter)
50#define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers))
51#define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers))
52
53/* Drop the inode semaphore and wait for a pipe event, atomically */
54void pipe_wait(struct inode * inode);
55
56struct inode* pipe_new(struct inode* inode);
57void free_pipe_info(struct inode* inode);
58
59#endif