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Diffstat (limited to 'kernel/include/linux/splice.h')
-rw-r--r-- | kernel/include/linux/splice.h | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/kernel/include/linux/splice.h b/kernel/include/linux/splice.h new file mode 100644 index 000000000..da2751d3b --- /dev/null +++ b/kernel/include/linux/splice.h @@ -0,0 +1,86 @@ +/* + * 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 */ + +/* + * 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 */ + unsigned int flags; /* splice flags */ + 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 splice_direct_to_actor(struct file *, struct splice_desc *, + splice_direct_actor *); + +/* + * 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 void spd_release_page(struct splice_pipe_desc *, unsigned int); + +extern const struct pipe_buf_operations page_cache_pipe_buf_ops; +#endif |