[PATCH 3/6] leases: break read leases on unlink

[Christoph Hellwig]

On Wed, Sep 21, 2011 at 10:58:14AM -0400, J. Bruce Fields wrote:
> A read lease is used by NFSv4 as a guarantee that a client can perform
> local read opens without informing the server.
> 
> The open operation takes the last component of the pathname as an
> argument, thus is also a lookup operation, and giving the client the
> above guarantee means informing the client before we allow anything that
> would change the set of names pointing to the inode.

That seems like totally strange semantics.  A useful defintion of a
lase operation would mean it guarantees I/O can happen, and wouldn't
care about metadata operation.  That's the whole point in adding a
stateful open to nfs4, isn't it?