| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* |
| * Function declerations and data structures related to the splice |
| * implementation. |
| * |
| * Copyright (C) 2007 Jens Axboe <jens.axboe@oracle.com> |
| * |
| */ |
| #ifndef SPLICE_H |
| #define SPLICE_H |
| |
| #include <linux/pipe_fs_i.h> |
| |
| /* |
| * Flags passed in from splice/tee/vmsplice |
| */ |
| #define SPLICE_F_MOVE (0x01) /* move pages instead of copying */ |
| #define SPLICE_F_NONBLOCK (0x02) /* don't block on the pipe splicing (but */ |
| /* we may still block on the fd we splice */ |
| /* from/to, of course */ |
| #define SPLICE_F_MORE (0x04) /* expect more data */ |
| #define SPLICE_F_GIFT (0x08) /* pages passed in are a gift */ |
| |
| #define SPLICE_F_ALL (SPLICE_F_MOVE|SPLICE_F_NONBLOCK|SPLICE_F_MORE|SPLICE_F_GIFT) |
| |
| /* |
| * Passed to the actors |
| */ |
| struct splice_desc { |
| size_t total_len; /* remaining length */ |
| unsigned int len; /* current length */ |
| unsigned int flags; /* splice flags */ |
| /* |
| * actor() private data |
| */ |
| union { |
| void __user *userptr; /* memory to write to */ |
| struct file *file; /* file to read/write */ |
| void *data; /* cookie */ |
| } u; |
| loff_t pos; /* file position */ |
| loff_t *opos; /* sendfile: output position */ |
| size_t num_spliced; /* number of bytes already spliced */ |
| bool need_wakeup; /* need to wake up writer */ |
| }; |
| |
| struct partial_page { |
| unsigned int offset; |
| unsigned int len; |
| unsigned long private; |
| }; |
| |
| /* |
| * Passed to splice_to_pipe |
| */ |
| struct splice_pipe_desc { |
| struct page **pages; /* page map */ |
| struct partial_page *partial; /* pages[] may not be contig */ |
| int nr_pages; /* number of populated pages in map */ |
| unsigned int nr_pages_max; /* pages[] & partial[] arrays size */ |
| const struct pipe_buf_operations *ops;/* ops associated with output pipe */ |
| void (*spd_release)(struct splice_pipe_desc *, unsigned int); |
| }; |
| |
| typedef int (splice_actor)(struct pipe_inode_info *, struct pipe_buffer *, |
| struct splice_desc *); |
| typedef int (splice_direct_actor)(struct pipe_inode_info *, |
| struct splice_desc *); |
| |
| extern ssize_t splice_from_pipe(struct pipe_inode_info *, struct file *, |
| loff_t *, size_t, unsigned int, |
| splice_actor *); |
| extern ssize_t __splice_from_pipe(struct pipe_inode_info *, |
| struct splice_desc *, splice_actor *); |
| extern ssize_t splice_to_pipe(struct pipe_inode_info *, |
| struct splice_pipe_desc *); |
| extern ssize_t add_to_pipe(struct pipe_inode_info *, |
| struct pipe_buffer *); |
| extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *, |
| splice_direct_actor *); |
| extern long do_splice(struct file *in, loff_t *off_in, |
| struct file *out, loff_t *off_out, |
| size_t len, unsigned int flags); |
| |
| extern long do_tee(struct file *in, struct file *out, size_t len, |
| unsigned int flags); |
| |
| /* |
| * for dynamic pipe sizing |
| */ |
| extern int splice_grow_spd(const struct pipe_inode_info *, struct splice_pipe_desc *); |
| extern void splice_shrink_spd(struct splice_pipe_desc *); |
| |
| extern const struct pipe_buf_operations page_cache_pipe_buf_ops; |
| extern const struct pipe_buf_operations default_pipe_buf_ops; |
| #endif |