1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Function declerations and data structures related to the splice 4 * implementation. 5 * 6 * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com> 7 * 8 */ 9 #ifndef SPLICE_H 10 #define SPLICE_H 11 12 #include <linux/pipe_fs_i.h> 13 14 /* 15 * Flags passed in from splice/tee/vmsplice 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 #define SPLICE_F_ALL (SPLICE_F_MOVE|SPLICE_F_NONBLOCK|SPLICE_F_MORE|SPLICE_F_GIFT) 25 26 /* 27 * Passed to the actors 28 */ 29 struct splice_desc { 30 size_t total_len; /* remaining length */ 31 unsigned int len; /* current length */ 32 unsigned int flags; /* splice flags */ 33 /* 34 * actor() private data 35 */ 36 union { 37 void __user *userptr; /* memory to write to */ 38 struct file *file; /* file to read/write */ 39 void *data; /* cookie */ 40 } u; 41 loff_t pos; /* file position */ 42 loff_t *opos; /* sendfile: output position */ 43 size_t num_spliced; /* number of bytes already spliced */ 44 bool need_wakeup; /* need to wake up writer */ 45 }; 46 47 struct partial_page { 48 unsigned int offset; 49 unsigned int len; 50 unsigned long private; 51 }; 52 53 /* 54 * Passed to splice_to_pipe 55 */ 56 struct splice_pipe_desc { 57 struct page **pages; /* page map */ 58 struct partial_page *partial; /* pages[] may not be contig */ 59 int nr_pages; /* number of populated pages in map */ 60 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */ 61 const struct pipe_buf_operations *ops;/* ops associated with output pipe */ 62 void (*spd_release)(struct splice_pipe_desc *, unsigned int); 63 }; 64 65 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, 66 struct splice_desc *); 67 typedef int (splice_direct_actor)(struct pipe_inode_info *, 68 struct splice_desc *); 69 70 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, 71 loff_t *, size_t, unsigned int, 72 splice_actor *); 73 extern ssize_t __splice_from_pipe(struct pipe_inode_info *, 74 struct splice_desc *, splice_actor *); 75 extern ssize_t splice_to_pipe(struct pipe_inode_info *, 76 struct splice_pipe_desc *); 77 extern ssize_t add_to_pipe(struct pipe_inode_info *, 78 struct pipe_buffer *); 79 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, 80 splice_direct_actor *); 81 82 /* 83 * for dynamic pipe sizing 84 */ 85 extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); 86 extern void splice_shrink_spd(struct splice_pipe_desc *); 87 88 extern const struct pipe_buf_operations page_cache_pipe_buf_ops; 89 extern const struct pipe_buf_operations default_pipe_buf_ops; 90 #endif 91