On 08/11/2015 11:30 AM, David Disseldorp wrote: > Hi Christoph, > > On Tue, 4 Aug 2015 09:11:05 +0200, Christoph Hellwig wrote: > >> This series adds support for a simplified persistent reservation API >> to the block layer. The intent is that both in-kernel and userspace >> consumers can use the API instead of having to hand craft SCSI or NVMe >> command through the various pass through interfaces. It also adds >> DM support as getting reservations through dm-multipath is a major >> pain with the current scheme. >> >> NVMe support currently isn't included as I don't have a multihost >> NVMe setup to test on, but if I can find a volunteer to test it I'm >> happy to write the code for it. >> >> The ioctl API is documented in Documentation/block/pr.txt, but to >> fully understand the concept you'll have to read up the SPC spec, >> PRs are too complicated that trying to rephrase them into different >> terminology is just going to create confusion. > > Do you have any thoughts on where SCSI-2 RESERVE/RELEASE should fit into > this API, if at all? I.e. as a new enum pr_type members for > pr_reserve()/pr_release(), as separate pr_ops hooks, etc? > Similarly for PR_IN - IIUC, if LIO is to handle cluster wide PRs > for Ceph rbd via the block layer, these will all need to be supported > by block layer (and LIO backend) APIs. > Just don't. Ignore SCSI-2 RESERVE/RELEASE. To my knowledge there are _no_ 'real' SCSI-2 systems in the market anymore; those which you might come across are 'fake' devices, trying to emulate SCSI-2 for backwards compability despite being in fact SCSI-3 devices. I would vote for just ignoring them. Simply not worth the pain. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
