1 /* 2 * Function declerations and data structures related to the splice 3 * implementation. 4 * 5 * Copyright (C) 2007 Jens Axboe <[email protected]> 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 size_t num_spliced; /* number of bytes already spliced */ 40 bool need_wakeup; /* need to wake up writer */ 41 }; 42 43 struct partial_page { 44 unsigned int offset; 45 unsigned int len; 46 unsigned long private; 47 }; 48 49 /* 50 * Passed to splice_to_pipe 51 */ 52 struct splice_pipe_desc { 53 struct page **pages; /* page map */ 54 struct partial_page *partial; /* pages[] may not be contig */ 55 int nr_pages; /* number of pages in map */ 56 unsigned int flags; /* splice flags */ 57 const struct pipe_buf_operations *ops;/* ops associated with output pipe */ 58 void (*spd_release)(struct splice_pipe_desc *, unsigned int); 59 }; 60 61 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, 62 struct splice_desc *); 63 typedef int (splice_direct_actor)(struct pipe_inode_info *, 64 struct splice_desc *); 65 66 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, 67 loff_t *, size_t, unsigned int, 68 splice_actor *); 69 extern ssize_t __splice_from_pipe(struct pipe_inode_info *, 70 struct splice_desc *, splice_actor *); 71 extern int splice_from_pipe_feed(struct pipe_inode_info *, struct splice_desc *, 72 splice_actor *); 73 extern int splice_from_pipe_next(struct pipe_inode_info *, 74 struct splice_desc *); 75 extern void splice_from_pipe_begin(struct splice_desc *); 76 extern void splice_from_pipe_end(struct pipe_inode_info *, 77 struct splice_desc *); 78 extern int pipe_to_file(struct pipe_inode_info *, struct pipe_buffer *, 79 struct splice_desc *); 80 81 extern ssize_t splice_to_pipe(struct pipe_inode_info *, 82 struct splice_pipe_desc *); 83 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, 84 splice_direct_actor *); 85 86 #endif 87