123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106 |
- #ifndef _LINUX_PIPE_FS_I_H
- #define _LINUX_PIPE_FS_I_H
- #define PIPEFS_MAGIC 0x50495045
- #define PIPE_BUFFERS (16)
- #define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
- #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
- #define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
- struct pipe_buffer {
- struct page *page;
- unsigned int offset, len;
- const struct pipe_buf_operations *ops;
- unsigned int flags;
- };
- /*
- * Note on the nesting of these functions:
- *
- * ->pin()
- * ->steal()
- * ...
- * ->map()
- * ...
- * ->unmap()
- *
- * That is, ->map() must be called on a pinned buffer, same goes for ->steal().
- */
- struct pipe_buf_operations {
- int can_merge;
- void * (*map)(struct pipe_inode_info *, struct pipe_buffer *, int);
- void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *, void *);
- int (*pin)(struct pipe_inode_info *, struct pipe_buffer *);
- void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
- int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
- void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
- };
- struct pipe_inode_info {
- wait_queue_head_t wait;
- unsigned int nrbufs, curbuf;
- struct page *tmp_page;
- unsigned int readers;
- unsigned int writers;
- unsigned int waiting_writers;
- unsigned int r_counter;
- unsigned int w_counter;
- struct fasync_struct *fasync_readers;
- struct fasync_struct *fasync_writers;
- struct inode *inode;
- struct pipe_buffer bufs[PIPE_BUFFERS];
- };
- /* 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
- /* Drop the inode semaphore and wait for a pipe event, atomically */
- void pipe_wait(struct pipe_inode_info *pipe);
- struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
- void free_pipe_info(struct inode * inode);
- void __free_pipe_info(struct pipe_inode_info *);
- /* Generic pipe buffer ops functions */
- void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *, int);
- void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *, void *);
- void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
- int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *);
- int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
- /*
- * splice is tied to pipes as a transport (at least for now), so we'll just
- * add the splice flags here.
- */
- #define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
- #define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
- /* we may still block on the fd we splice */
- /* from/to, of course */
- #define SPLICE_F_MORE (0x04) /* expect more data */
- #define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
- /*
- * Passed to the actors
- */
- struct splice_desc {
- unsigned int len, total_len; /* current and remaining length */
- unsigned int flags; /* splice flags */
- struct file *file; /* file to read/write */
- loff_t pos; /* file position */
- };
- typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
- struct splice_desc *);
- extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
- loff_t *, size_t, unsigned int,
- splice_actor *);
- extern ssize_t __splice_from_pipe(struct pipe_inode_info *, struct file *,
- loff_t *, size_t, unsigned int,
- splice_actor *);
- #endif
|