Lustre & special file ops

Lustre & special file ops

[Peter Braam]

Hi, 

Lustre is a cluster file system that has a client server architecture.
When a client opens a file, the server sees an open call.  This is
done so that the server can take care to handle open-unlinked files
correctly across cluster nodes.  For regular and directory files this
is fairly straightforward.

We also want to handle open-unlinked special files correctly, since
operations like fchmod and fstat on different cluster nodes issued on
file descriptors associated with open special files still require
synchronization through the server.

This requires non-standard open/close methods on the special files.
So we would like Lustre to roughly do something like:

ll_special_open(struct inode *inode, struct  file *file)
{
  1. do what init_special_inode installs
  2. do open RPC on the metadata server
} 

Is there an elegant, simple way to accomplish this? 

Thanks for any help!

- Peter -