1 #ifndef _LINUX_PIPE_FS_I_H
2 #define _LINUX_PIPE_FS_I_H
4 #define PIPEFS_MAGIC 0x50495045
6 #define PIPE_BUFFERS (16)
8 #define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
9 #define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
13 unsigned int offset
, len
;
14 struct pipe_buf_operations
*ops
;
19 * Note on the nesting of these functions:
28 * That is, ->map() must be called on a pinned buffer, same goes for ->steal().
30 struct pipe_buf_operations
{
32 void * (*map
)(struct pipe_inode_info
*, struct pipe_buffer
*, int);
33 void (*unmap
)(struct pipe_inode_info
*, struct pipe_buffer
*, void *);
34 int (*pin
)(struct pipe_inode_info
*, struct pipe_buffer
*);
35 void (*release
)(struct pipe_inode_info
*, struct pipe_buffer
*);
36 int (*steal
)(struct pipe_inode_info
*, struct pipe_buffer
*);
37 void (*get
)(struct pipe_inode_info
*, struct pipe_buffer
*);
40 struct pipe_inode_info
{
41 wait_queue_head_t wait
;
42 unsigned int nrbufs
, curbuf
;
43 struct pipe_buffer bufs
[PIPE_BUFFERS
];
44 struct page
*tmp_page
;
48 unsigned int waiting_writers
;
49 unsigned int r_counter
;
50 unsigned int w_counter
;
51 struct fasync_struct
*fasync_readers
;
52 struct fasync_struct
*fasync_writers
;
56 /* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
57 memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
58 #define PIPE_SIZE PAGE_SIZE
60 /* Drop the inode semaphore and wait for a pipe event, atomically */
61 void pipe_wait(struct pipe_inode_info
*pipe
);
63 struct pipe_inode_info
* alloc_pipe_info(struct inode
* inode
);
64 void free_pipe_info(struct inode
* inode
);
65 void __free_pipe_info(struct pipe_inode_info
*);
67 /* Generic pipe buffer ops functions */
68 void *generic_pipe_buf_map(struct pipe_inode_info
*, struct pipe_buffer
*, int);
69 void generic_pipe_buf_unmap(struct pipe_inode_info
*, struct pipe_buffer
*, void *);
70 void generic_pipe_buf_get(struct pipe_inode_info
*, struct pipe_buffer
*);
71 int generic_pipe_buf_pin(struct pipe_inode_info
*, struct pipe_buffer
*);
74 * splice is tied to pipes as a transport (at least for now), so we'll just
75 * add the splice flags here.
77 #define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
78 #define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
79 /* we may still block on the fd we splice */
80 /* from/to, of course */
81 #define SPLICE_F_MORE (0x04) /* expect more data */
84 * Passed to the actors
87 unsigned int len
, total_len
; /* current and remaining length */
88 unsigned int flags
; /* splice flags */
89 struct file
*file
; /* file to read/write */
90 loff_t pos
; /* file position */
93 typedef int (splice_actor
)(struct pipe_inode_info
*, struct pipe_buffer
*,
94 struct splice_desc
*);
96 extern ssize_t
splice_from_pipe(struct pipe_inode_info
*, struct file
*,
97 loff_t
*, size_t, unsigned int,
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