FS-Cache, NFS and page bits

[Trond Myklebust]

On Fri, 2006-12-08 at 16:49 +0000, David Howells wrote:
> Hi Trond, Linus,
> 
> I've just updated my FS-Cache tree to the latest Linus head - or at least
> I tried to.
> 
> I was using a bit in page->private to indicate that a page was cached and might
> be holding cache resources.  I was previously using PG_private, but Trond
> claimed that for his own.  I moved my Trond's PG_private and my bit into
> page->private and used PG_private to indicate that one of these bits was set.
> However, Trond has now claimed page->private for something else too, and I
> appear to have run out of bits.

Why is it a problem? AFAIR you were supposed to be disabling cachefs on
files that are open for write. NFS only uses PagePrivate and
page->private for pages which are under writeback.

Cheers
  Trond