[openib-general] oops after rmmod ib_cm when stopping iSER

[Sean Hefty]

Erez Zilber wrote:
> When stopping iSER, we run 'modprobe -r ib_iser'. Then, we see an oops 
> (below). In order to check which module caused that oops, I replaced the 
> 'modprobe -r' call with rmmod for each module:
> 
> rmmod ib_iser
> rmmod libiscsi
> rmmod scsi_transport_iscsi
> rmmod rdma_cm
> rmmod ib_addr
> rmmod ib_cm
> 
> If I wait a few seconds before the removal of ib_cm, everything is ok.

Thanks for the info.  My guess is that the cm_id's are not taking a reference on 
the cm devices, which is allowing the module unload to proceed while cm_id's 
still remain in timewait.  I will look at this in more detail and work on a 
patch.  How reproducible is this?

- Sean