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1da177e4 LT |
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 | ||
8 | struct pipe_buffer { | |
9 | struct page *page; | |
10 | unsigned int offset, len; | |
11 | struct pipe_buf_operations *ops; | |
12 | }; | |
13 | ||
14 | struct 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 | ||
21 | struct 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 | ||
1b1dcc1b | 40 | #define PIPE_MUTEX(inode) (&(inode).i_mutex) |
1da177e4 | 41 | #define PIPE_WAIT(inode) (&(inode).i_pipe->wait) |
1da177e4 LT |
42 | #define PIPE_READERS(inode) ((inode).i_pipe->readers) |
43 | #define PIPE_WRITERS(inode) ((inode).i_pipe->writers) | |
44 | #define PIPE_WAITING_WRITERS(inode) ((inode).i_pipe->waiting_writers) | |
45 | #define PIPE_RCOUNTER(inode) ((inode).i_pipe->r_counter) | |
46 | #define PIPE_WCOUNTER(inode) ((inode).i_pipe->w_counter) | |
47 | #define PIPE_FASYNC_READERS(inode) (&((inode).i_pipe->fasync_readers)) | |
48 | #define PIPE_FASYNC_WRITERS(inode) (&((inode).i_pipe->fasync_writers)) | |
49 | ||
50 | /* Drop the inode semaphore and wait for a pipe event, atomically */ | |
51 | void pipe_wait(struct inode * inode); | |
52 | ||
53 | struct inode* pipe_new(struct inode* inode); | |
54 | void free_pipe_info(struct inode* inode); | |
55 | ||
56 | #endif |