David S. Miller wrote:
>    From: Jeff Garzik <jgarzik@mandrakesoft.com>
>    Date: Mon, 16 Sep 2002 19:48:37 -0400
> 
>    I dunno when it happened, but 2.5.x now returns EINVAL for all 
>    file->file cases.
>    
>    In 2.4.x, if sendpage is NULL, file_send_actor in mm/filemap.c faked a 
>    call to fops->write().
>    In 2.5.x, if sendpage is NULL, EINVAL is unconditionally returned.
>    
> 
> What if source and destination file and offsets match?


The same data is written out.  No deadlock.
(unless the attached test is wrong)

	Jeff