blob: ea4f7cd7bfd85425c96a1d17faa358a2d7cb509f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_PIPE_FS_I_H
2#define _LINUX_PIPE_FS_I_H
3
4#define PIPEFS_MAGIC 0x50495045
5
6#define PIPE_BUFFERS (16)
7
Jens Axboe14328732006-05-03 10:35:26 +02008#define PIPE_BUF_FLAG_LRU 0x01 /* page is on the LRU */
9#define PIPE_BUF_FLAG_ATOMIC 0x02 /* was atomically mapped */
10#define PIPE_BUF_FLAG_GIFT 0x04 /* page is a gift */
Jens Axboe3e7ee3e2006-04-02 23:11:04 +020011
Linus Torvalds1da177e2005-04-16 15:20:36 -070012struct pipe_buffer {
13 struct page *page;
14 unsigned int offset, len;
15 struct pipe_buf_operations *ops;
Jens Axboe3e7ee3e2006-04-02 23:11:04 +020016 unsigned int flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070017};
18
Jens Axboef84d7512006-05-01 19:59:03 +020019/*
20 * Note on the nesting of these functions:
21 *
22 * ->pin()
23 * ->steal()
24 * ...
25 * ->map()
26 * ...
27 * ->unmap()
28 *
29 * That is, ->map() must be called on a pinned buffer, same goes for ->steal().
30 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070031struct pipe_buf_operations {
32 int can_merge;
Jens Axboef6762b72006-05-01 20:02:05 +020033 void * (*map)(struct pipe_inode_info *, struct pipe_buffer *, int);
34 void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *, void *);
Jens Axboef84d7512006-05-01 19:59:03 +020035 int (*pin)(struct pipe_inode_info *, struct pipe_buffer *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
Jens Axboe5abc97a2006-03-30 15:16:46 +020037 int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
Jens Axboe70524492006-04-11 15:51:17 +020038 void (*get)(struct pipe_inode_info *, struct pipe_buffer *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039};
40
41struct pipe_inode_info {
42 wait_queue_head_t wait;
43 unsigned int nrbufs, curbuf;
44 struct pipe_buffer bufs[PIPE_BUFFERS];
45 struct page *tmp_page;
46 unsigned int start;
47 unsigned int readers;
48 unsigned int writers;
49 unsigned int waiting_writers;
50 unsigned int r_counter;
51 unsigned int w_counter;
52 struct fasync_struct *fasync_readers;
53 struct fasync_struct *fasync_writers;
Ingo Molnar3a326a22006-04-10 15:18:35 +020054 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
56
57/* Differs from PIPE_BUF in that PIPE_SIZE is the length of the actual
58 memory allocation, whereas PIPE_BUF makes atomicity guarantees. */
59#define PIPE_SIZE PAGE_SIZE
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061/* Drop the inode semaphore and wait for a pipe event, atomically */
Ingo Molnar3a326a22006-04-10 15:18:35 +020062void pipe_wait(struct pipe_inode_info *pipe);
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
Ingo Molnar3a326a22006-04-10 15:18:35 +020064struct pipe_inode_info * alloc_pipe_info(struct inode * inode);
65void free_pipe_info(struct inode * inode);
Jens Axboeb92ce552006-04-11 13:52:07 +020066void __free_pipe_info(struct pipe_inode_info *);
Linus Torvalds1da177e2005-04-16 15:20:36 -070067
Jens Axboef84d7512006-05-01 19:59:03 +020068/* Generic pipe buffer ops functions */
Jens Axboef6762b72006-05-01 20:02:05 +020069void *generic_pipe_buf_map(struct pipe_inode_info *, struct pipe_buffer *, int);
70void generic_pipe_buf_unmap(struct pipe_inode_info *, struct pipe_buffer *, void *);
Jens Axboef84d7512006-05-01 19:59:03 +020071void generic_pipe_buf_get(struct pipe_inode_info *, struct pipe_buffer *);
72int generic_pipe_buf_pin(struct pipe_inode_info *, struct pipe_buffer *);
Jens Axboe330ab712006-05-02 15:29:57 +020073int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
Jens Axboef84d7512006-05-01 19:59:03 +020074
Jens Axboe5abc97a2006-03-30 15:16:46 +020075/*
76 * splice is tied to pipes as a transport (at least for now), so we'll just
77 * add the splice flags here.
78 */
79#define SPLICE_F_MOVE (0x01) /* move pages instead of copying */
Linus Torvalds29e35092006-04-02 12:46:35 -070080#define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */
81 /* we may still block on the fd we splice */
82 /* from/to, of course */
Jens Axboeb2b39fa2006-04-02 23:05:41 +020083#define SPLICE_F_MORE (0x04) /* expect more data */
Jens Axboe7afa6fd2006-05-01 20:02:33 +020084#define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */
Jens Axboe5abc97a2006-03-30 15:16:46 +020085
Jens Axboe00522fb2006-04-26 14:39:29 +020086/*
87 * Passed to the actors
88 */
89struct splice_desc {
90 unsigned int len, total_len; /* current and remaining length */
91 unsigned int flags; /* splice flags */
92 struct file *file; /* file to read/write */
93 loff_t pos; /* file position */
94};
95
96typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *,
97 struct splice_desc *);
98
99extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *,
100 loff_t *, size_t, unsigned int,
101 splice_actor *);
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103#endif