+extern ssize_t generic_file_splice_read(struct file *, struct pipe_inode_info *, size_t, unsigned int);
+extern ssize_t generic_file_splice_write(struct pipe_inode_info *, struct file *, size_t, unsigned int);
+extern long do_splice_direct(struct file *in, struct file *out,
+ size_t len, unsigned int flags);