Re: [PATCH 0/2] : definion, code, and use of new SCSI ML host status DID_COND_REQUEUE

[Edward Goggin <egoggin@vmware.com>]

On Fri, 2007-02-02 at 17:18 -0600, James Bottomley wrote:
> On Fri, 2007-02-02 at 18:11 -0500, Edward Goggin wrote:
> > That solution doesn't work for the RDAC/MPP driver as the BUSY status
> > handler retries indefinitely.  We need a solution which works for both a
> > bare metal host running RDAC/MPP which for this use case, wants to get
> > control over the failed command ASAP and a VMware host which may need to
> > retry longer than DID_BUS_BUSY currently allows for.
> 
> No it doesn't, not any longer... the mid-layer retries for the command
> up to its timeout before failing.  That's the point about questioning
> the validity of the original problem.
> 
> James
> 
> 

I think I see your argument ... retries for BUSY and all other scsi/host
status's are limited by the code in scsi_softirq_done which filters the
disposition returned by scsi_decide_disposition, so no status will yield
an indefinite retry.

Not clear if that's soon enough for RDAC/MPP.  For the VMware case, it
appears to allow an additional 30 seconds (beyond what DID_BUSY_BUSY
would allow) for a retry.