On 03/05/2014 09:23 AM, Bart Van Assche wrote: > On 03/05/14 09:00, Hannes Reinecke wrote: >> On 03/02/2014 09:53 AM, Bart Van Assche wrote: >>> A general comment about this patch series: I think the cached copies of >>> these pages should be refreshed at least after an INQUIRY DATA HAS >>> CHANGED unit attention code has been received. Some SCSI target >>> implementations allow to change this data after a LUN has been created. >> >> Yes, eventually. But this needs to be handled in a general context, >> as (potentially) even the inquiry string itself has been invalidated >> after receiving such an event. >> So we should be doing a rescan of the scsi device upon receiving >> such an event. But this is a general problem, not one particular to >> this patchset. > > Sorry but since the ALUA patch series is based on this patch series I'm > afraid that the ALUA patch series introduces a regression that seems > unacceptable to me. SCSI target implementations like LIO allow to remove > and re-add a LUN after initial discovery of a SCSI host. My concern here > is that the caching introduced by this patch series and which is used in > the ALUA patch series will cause INQUIRY data not to be updated after it > has been changed at the target side. Today the scsi_dh_alua handler > processes such INQUIRY data changes fine. Does this make sense to you ? > Currently, the SCSI stack itself is not well-equipped to handle these kind of setups anyway. (The only known working solution is to remove the device _entirely_ and have the HBA rescan the LUN). So while you are right I'm still preferring to keep those two issues separate.
James, any preferences here? Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage h...@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
