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#ifndef _LINUX_PIPE_FS_I_H
#define _LINUX_PIPE_FS_I_H
struct pipe_inode_info {
wait_queue_head_t wait;
char *base;
unsigned int start;
unsigned int readers;
unsigned int 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_SEM(inode) (&(inode).i_sem)
#define PIPE_WAIT(inode) (&(inode).i_pipe->wait)
#define PIPE_BASE(inode) ((inode).i_pipe->base)
#define PIPE_START(inode) ((inode).i_pipe->start)
#define PIPE_LEN(inode) ((inode).i_size)
#define PIPE_READERS(inode) ((inode).i_pipe->readers)
#define PIPE_WRITERS(inode) ((inode).i_pipe->writers)
#define PIPE_EMPTY(inode) (PIPE_LEN(inode) == 0)
#define PIPE_FULL(inode) (PIPE_LEN(inode) == PIPE_SIZE)
#define PIPE_FREE(inode) (PIPE_SIZE - PIPE_LEN(inode))
#define PIPE_END(inode) ((PIPE_START(inode) + PIPE_LEN(inode)) & (PIPE_SIZE-1))
#define PIPE_MAX_RCHUNK(inode) (PIPE_SIZE - PIPE_START(inode))
#define PIPE_MAX_WCHUNK(inode) (PIPE_SIZE - PIPE_END(inode))
#endif
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