When doing open by handle, a requirement is that it be possible to open already open unlinked files. This is important for the sort of userspace NFS server/ i/o forwarder (DVS) uses that file handles are intended for.

This works from one node in Lustre, but not across multiple nodes. This looks fixable - It's possible to open an orphaned file, it seems to be as simple as using the code from mdd_close in mdd_open, particularly rewriting the "EEXIST check" (mdd_is_dead_obj) to check if the object is an orphan and then open it anyway.

Patch forthcoming.