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 void (*splice_eof)(struct splice_desc *sd); /* Unexpected EOF handler */ 42 loff_t pos; /* file position */ 43 loff_t *opos; /* sendfile: output position */ 44 size_t num_spliced; /* number of bytes already spliced */ 45 bool need_wakeup; /* need to wake up writer */ 46 }; 47 48 struct partial_page { 49 unsigned int offset; 50 unsigned int len; 51 unsigned long private; 52 }; 53 54 /* 55 * Passed to splice_to_pipe 56 */ 57 struct splice_pipe_desc { 58 struct page **pages; /* page map */ 59 struct partial_page *partial; /* pages[] may not be contig */ 60 int nr_pages; /* number of populated pages in map */ 61 unsigned int nr_pages_max; /* pages[] & partial[] arrays size */ 62 const struct pipe_buf_operations *ops;/* ops associated with output pipe */ 63 void (*spd_release)(struct splice_pipe_desc *, unsigned int); 64 }; 65 66 typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, 67 struct splice_desc *); 68 typedef int (splice_direct_actor)(struct pipe_inode_info *, 69 struct splice_desc *); 70 71 extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, 72 loff_t *, size_t, unsigned int, 73 splice_actor *); 74 extern ssize_t __splice_from_pipe(struct pipe_inode_info *, 75 struct splice_desc *, splice_actor *); 76 extern ssize_t splice_to_pipe(struct pipe_inode_info *, 77 struct splice_pipe_desc *); 78 extern ssize_t add_to_pipe(struct pipe_inode_info *, 79 struct pipe_buffer *); 80 long vfs_splice_read(struct file *in, loff_t *ppos, 81 struct pipe_inode_info *pipe, size_t len, 82 unsigned int flags); 83 extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, 84 splice_direct_actor *); 85 extern long do_splice(struct file *in, loff_t *off_in, 86 struct file *out, loff_t *off_out, 87 size_t len, unsigned int flags); 88 89 extern long do_tee(struct file *in, struct file *out, size_t len, 90 unsigned int flags); 91 extern ssize_t splice_to_socket(struct pipe_inode_info *pipe, struct file *out, 92 loff_t *ppos, size_t len, unsigned int flags); 93 94 /* 95 * for dynamic pipe sizing 96 */ 97 extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); 98 extern void splice_shrink_spd(struct splice_pipe_desc *); 99 100 extern const struct pipe_buf_operations page_cache_pipe_buf_ops; 101 extern const struct pipe_buf_operations default_pipe_buf_ops; 102 #endif 103