[openib-general] rdma_cm callback event private data length == 0

[Sean Hefty]

Ira Weiny wrote:
> The "problem" with the private_data_len being 0 appears to be in the
> cma_ib_handler function.  The following is a patch which simply tells the user
> the private data length for the REJ message.  Lustre, which checks this length,
> then happily gets its data.  Is this a bug which needs to be fixed for all the
> CM messages?  Or is it incorrect to look at this length to determine if there
> is private data included in the message?  Since the ib_cm_event structure does
> not have a length for this data I don't know how else to set this value?

This is a bug.  The private_data_len should have been set as done in your patch.

(The IB CM protocol does not indicate if any of the private data is valid, so 
must be passed through to the consumer as if the entire data is valid.)

I've committed a fix in svn 8483 based on your patch (minus the if-statement).

Thanks,
- Sean