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; 44 unsigned long private; 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 void (*spd_release)(struct splice_pipe_desc *, unsigned int); 57 }; 58 59 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, 60 struct splice_desc *); 61 typedef int (splice_direct_actor)(struct pipe_inode_info *, 62 struct splice_desc *); 63 64 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, 65 loff_t *, size_t, unsigned int, 66 splice_actor *); 67 extern ssize_t __splice_from_pipe(struct pipe_inode_info *, 68 struct splice_desc *, splice_actor *); 69 extern ssize_t splice_to_pipe(struct pipe_inode_info *, 70 struct splice_pipe_desc *); 71 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, 72 splice_direct_actor *); 73 74 #endif 75