[nfsv4] question about CB_OFFLOAD

[Olga Kornievskaia <[e-mail]>]

I have a question about CB_OFFLOAD parameters.

16.1.3 states that "The coa_resok4.wr_callback_id MUST NOT be set”.
What does that mean? All zeros? If the field is never set why is it
there?

struct write_response4 {
           stateid4        wr_callback_id<1>;
           length4         wr_count;
           stable_how4     wr_committed;
           verifier4       wr_writeverf;
   };

   union offload_info4 switch (nfsstat4 coa_status) {
   case NFS4_OK:
           write_response4 coa_resok4;