Re: Merging se_dev_entry and se_lun?
On Fri, Jun 19, 2015 at 08:40:23AM +0200, Hannes Reinecke wrote: Having a list here implies that 'se_lun' can have _several_ se_dev_entry structure attached to it, which I found rather curious. Can you give me an example where this might be the case? Or can we replace the list with a simple pointer or even merge both? Each initiator has it's own dev entry. What might make sense with the new list-based dev entry handling is to merge the se_lun_acl and se_dev_entry, but it would be a fair amount of work. -- 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
Merging se_dev_entry and se_lun?
Hi Nic, having done the patch to export 'write_protect' for demo-mode LUNs I've came across one puzzling item: struct se_lun uses a list to refer to the underlying se_dev_entry structures. Which I found rather curious, as from my understanding 'se_lun' is the structure for the mapped LUN (ie the LUN visible to the initiator) and 'se_dev_entry' is the underlying physical device as visible to the LUN. As such I would have expected a 1:1 relationship between both, ie a simple pointer from se_lun to se_dev_entry. Having a list here implies that 'se_lun' can have _several_ se_dev_entry structure attached to it, which I found rather curious. Can you give me an example where this might be the case? Or can we replace the list with a simple pointer or even merge both? Reason I'm asking is the lun_access / dev_flags field; it really looks like it being a duplicate (I would judge 'write_protect' to be a property of the mapped LUN, and not of the underlying device), but in either case having it in both places requires a synchronisation between both, as for demo-mode LUNs we can only change it via se_lun, and for others we have to change it via the se_dev_entry. Cheers, Hannes -- Dr. Hannes ReineckezSeries Storage h...@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (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
Re: Merging se_dev_entry and se_lun?
On 06/19/2015 08:56 AM, Christoph Hellwig wrote: On Fri, Jun 19, 2015 at 08:40:23AM +0200, Hannes Reinecke wrote: Having a list here implies that 'se_lun' can have _several_ se_dev_entry structure attached to it, which I found rather curious. Can you give me an example where this might be the case? Or can we replace the list with a simple pointer or even merge both? Each initiator has it's own dev entry. But isn't 'se_lun' per initiator, too? Cheers, Hannes -- Dr. Hannes ReineckezSeries Storage h...@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line unsubscribe linux-scsi in
Re: Merging se_dev_entry and se_lun?
On Fri, Jun 19, 2015 at 03:21:27PM +0200, Hannes Reinecke wrote: Each initiator has it's own dev entry. But isn't 'se_lun' per initiator, too? No. -- To unsubscribe from this list: send the line unsubscribe linux-scsi in
