Re: [PATCH 0/4] scsi: remove devices in ALUA transitioning status

Martin K. Petersen
2020-10-27T00:21:49Z

Hannes,

> during testing we found that there is an issue with dev_loss_tmo and
> devices in ALUA transitioning state. What happens is that I/O gets
> requeued via BLK_STS_RESOURCE for these devices, so when dev_loss_tmo
> triggers the SCSI core cannot flush the request list as I/O is simply
> requeued.
>
> So when the driver is trying to re-establish the device it'll wait for
> that last reference to drop in order to re-attach the device, but as
> I/O is still outstanding on the (old) device it'll wait for ever.
>
> Fix this by returning 'BLK_STS_AGAIN' from scsi_dh_alua when the
> device is in ALUA transitioning, and also set the 'transitioning'
> state when scsi_dh_alua is receiving a sense code, and not only after
> scsi_dh_alua successfully received the response to a REPORT TARGET
> PORT GROUPS command.

It would be good to get this revived/reviewed.

Thanks!

--
Martin K. Petersen Oracle Linux Engineering