Re: [PATCH] scsi_transport_fc: Make 'port_state' writeable

[James Smart <James.Smart@emulex.com>]

I understand your points. But you will need to contact the different LLD 
maintainers to ensure receiving a devloss_tmo_callbk() on an rport they 
had not called fc_remote_port_delete() for.  I know there's work on my 
side to validate it's ok.  First glance was ok, but..

-- james s


On 4/4/2013 2:26 AM, Hannes Reinecke wrote:
> On 04/01/2013 11:06 PM, James Smart wrote:
>> I think lpfc survives your rport state change as : part of the lld
>> behavior on the callback, to clean up reference counts, is to abort
>> all i/o that is outstanding to the rport.   So the ref checking not
>> only protects lpfc from prematurely freeing a structure (my real
>> concern), but also just happens to abort all i/o.  We got lucky.
>>
>> I still believe the I_T_nexus reset is the right way to solve this.
>>
> Yes, but this would be an even more intrusive patch.
> And we would need to implement yet another callback into the LLDDs
> which need to be implemented there, too.
>
> But for this to make any sense we would need to revamp the scsi
> error handler, as the current problem is that error recovery takes
> too long. Adding yet another callback will make the escalation chain
> even longer.
>
> So yeah, in the long run I_T nexus reset is the correct way of doing
> things, but in the short term I would opt to make port_state
> writeable to simulate an I_T nexus reset.
>
> Cheers,
>
> Hannes