| #ifndef _LINUX_PIPE_FS_I_H |
| #define _LINUX_PIPE_FS_I_H |
| |
| #define PIPEFS_MAGIC 0x50495045 |
| struct pipe_inode_info { |
| wait_queue_head_t wait; |
| char *base; |
| unsigned int len; |
| unsigned int start; |
| unsigned int readers; |
| unsigned int writers; |
| unsigned int waiting_readers; |
| unsigned int waiting_writers; |
| unsigned int r_counter; |
| unsigned int w_counter; |
| }; |
| |
| /* 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_pipe->len) |
| #define PIPE_READERS(inode) ((inode).i_pipe->readers) |
| #define PIPE_WRITERS(inode) ((inode).i_pipe->writers) |
| #define PIPE_WAITING_READERS(inode) ((inode).i_pipe->waiting_readers) |
| #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_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)) |
| |
| /* Drop the inode semaphore and wait for a pipe event, atomically */ |
| void pipe_wait(struct inode * inode); |
| |
| struct inode* pipe_new(struct inode* inode); |
| |
| #endif |
