[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>

1 files changed, 8 insertions, 0 deletions

diff --git a/fs/pipe.c b/fs/pipe.c
index 2414bf270db6..109a102c150d 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -121,11 +121,19 @@ static void anon_pipe_buf_unmap(struct pipe_inode_info *info, struct pipe_buffer
         kunmap(buf->page);
 }
 
+static int anon_pipe_buf_steal(struct pipe_inode_info *info,
+                               struct pipe_buffer *buf)
+{
+        buf->stolen = 1;
+        return 0;
+}
+
 static struct pipe_buf_operations anon_pipe_buf_ops = {
         .can_merge = 1,
         .map = anon_pipe_buf_map,
         .unmap = anon_pipe_buf_unmap,
         .release = anon_pipe_buf_release,
+        .steal = anon_pipe_buf_steal,
 };
 
 static ssize_t