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