[PATCH] splice: add support for SPLICE_F_MOVE flag
This enables the caller to migrate pages from one address space page
cache to another. In buzz word marketing, you can do zero-copy file
copies!
Signed-off-by: Jens Axboe <axboe@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index b12e59c..75c7f55 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -9,6 +9,7 @@
struct page *page;
unsigned int offset, len;
struct pipe_buf_operations *ops;
+ unsigned int stolen;
};
struct pipe_buf_operations {
@@ -16,6 +17,7 @@
void * (*map)(struct file *, struct pipe_inode_info *, struct pipe_buffer *);
void (*unmap)(struct pipe_inode_info *, struct pipe_buffer *);
void (*release)(struct pipe_inode_info *, struct pipe_buffer *);
+ int (*steal)(struct pipe_inode_info *, struct pipe_buffer *);
};
struct pipe_inode_info {
@@ -53,4 +55,10 @@
struct inode* pipe_new(struct inode* inode);
void free_pipe_info(struct inode* inode);
+/*
+ * 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 */
+
#endif