v4.19.13 snapshot.
diff --git a/include/linux/splice.h b/include/linux/splice.h
new file mode 100644
index 0000000..74b4911
--- /dev/null
+++ b/include/linux/splice.h
@@ -0,0 +1,90 @@
+/* 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 *);
+
+/*
+ * 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