Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Function declerations and data structures related to the splice |
| 3 | * implementation. |
| 4 | * |
| 5 | * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com> |
| 6 | * |
| 7 | */ |
| 8 | #ifndef SPLICE_H |
| 9 | #define SPLICE_H |
| 10 | |
| 11 | #include <linux/pipe_fs_i.h> |
| 12 | |
| 13 | /* |
| 14 | * splice is tied to pipes as a transport (at least for now), so we'll just |
| 15 | * add the splice flags here. |
| 16 | */ |
| 17 | #define SPLICE_F_MOVE (0x01) /* move pages instead of copying */ |
| 18 | #define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */ |
| 19 | /* we may still block on the fd we splice */ |
| 20 | /* from/to, of course */ |
| 21 | #define SPLICE_F_MORE (0x04) /* expect more data */ |
| 22 | #define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */ |
| 23 | |
| 24 | /* |
| 25 | * Passed to the actors |
| 26 | */ |
| 27 | struct splice_desc { |
| 28 | unsigned int len, total_len; /* current and remaining length */ |
| 29 | unsigned int flags; /* splice flags */ |
| 30 | /* |
| 31 | * actor() private data |
| 32 | */ |
| 33 | union { |
| 34 | void __user *userptr; /* memory to write to */ |
| 35 | struct file *file; /* file to read/write */ |
| 36 | void *data; /* cookie */ |
| 37 | } u; |
| 38 | loff_t pos; /* file position */ |
| 39 | }; |
| 40 | |
| 41 | struct partial_page { |
| 42 | unsigned int offset; |
| 43 | unsigned int len; |
Jens Axboe | 497f962 | 2007-06-11 12:00:45 +0200 | [diff] [blame] | 44 | unsigned long private; |
Jens Axboe | d6b29d7 | 2007-06-04 09:59:47 +0200 | [diff] [blame] | 45 | }; |
| 46 | |
| 47 | /* |
| 48 | * Passed to splice_to_pipe |
| 49 | */ |
| 50 | struct splice_pipe_desc { |
| 51 | struct page **pages; /* page map */ |
| 52 | struct partial_page *partial; /* pages[] may not be contig */ |
| 53 | int nr_pages; /* number of pages in map */ |
| 54 | unsigned int flags; /* splice flags */ |
| 55 | const struct pipe_buf_operations *ops;/* ops associated with output pipe */ |
| 56 | }; |
| 57 | |
| 58 | typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, |
| 59 | struct splice_desc *); |
| 60 | typedef int (splice_direct_actor)(struct pipe_inode_info *, |
| 61 | struct splice_desc *); |
| 62 | |
| 63 | extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, |
| 64 | loff_t *, size_t, unsigned int, |
| 65 | splice_actor *); |
| 66 | extern ssize_t __splice_from_pipe(struct pipe_inode_info *, |
| 67 | struct splice_desc *, splice_actor *); |
| 68 | extern ssize_t splice_to_pipe(struct pipe_inode_info *, |
| 69 | struct splice_pipe_desc *); |
| 70 | extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, |
| 71 | splice_direct_actor *); |
| 72 | |
| 73 | #endif |