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authorJens Axboe <jens.axboe@oracle.com>2007-06-04 09:59:47 +0200
committerJens Axboe <jens.axboe@oracle.com>2007-07-10 08:04:14 +0200
commitd6b29d7cee064f28ca097e906de7453541351095 (patch)
tree16775787df194cb45b4ac712da1c240f48cae96e /include/linux/splice.h
parentebf9909343392c929d9943c04f421cd42e03b530 (diff)
downloadop-kernel-dev-d6b29d7cee064f28ca097e906de7453541351095.zip
op-kernel-dev-d6b29d7cee064f28ca097e906de7453541351095.tar.gz
splice: divorce the splice structure/function definitions from the pipe header
We need to move even more stuff into the header so that folks can use the splice_to_pipe() implementation instead of open-coding a lot of pipe knowledge (see relay implementation), so move to our own header file finally. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/linux/splice.h')
-rw-r--r--include/linux/splice.h72
1 files changed, 72 insertions, 0 deletions
diff --git a/include/linux/splice.h b/include/linux/splice.h
new file mode 100644
index 0000000..f8cc97f
--- /dev/null
+++ b/include/linux/splice.h
@@ -0,0 +1,72 @@
+/*
+ * 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>
+
+/*
+ * splice is tied to pipes as a transport (at least for now), so we'll just
+ * add the splice flags here.
+ */
+#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 {
+ unsigned int len, total_len; /* current and remaining 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 */
+};
+
+struct partial_page {
+ unsigned int offset;
+ unsigned int len;
+};
+
+/*
+ * 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 pages in map */
+ unsigned int flags; /* splice flags */
+ const struct pipe_buf_operations *ops;/* ops associated with output pipe */
+};
+
+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 *);
+
+#endif
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