Re: [PATCH 0/5] target/rbd: distributed lun reset support

[Mike Christie <mchristi@redhat.com>]

On 05/05/2015 04:56 AM, mchristi@redhat.com wrote:
> The following patches allow drivers like libceph/rbd to distribute
> execution of scsi task management functions across multiple nodes
> (still working on issues with distributed PRs).
> 
> In this patchset, I added a new type of callout/module for these
> cluster aware modules. The idea is that something like drbd could maybe do
> something optimized for them, or nbd could, or you could use dlm
> plus some file system, or do something cluster FS specific. For rbd
> we are making rados/libceph calls.
> 
> I am mostly looking for feedback on the hooks/callouts approach. I was
> not sure if we wanted to maybe instead do somethign like add new callouts
> to the request_queue (request_queue->reset_q) or block_device or
> add some new block layer REQ_TYPEs (REQ_TYPE_DEVICE_RESET or
> REQ_TYPE_PGR_REGISTER, etc). In this patchset I just added new
> callouts that modules can implement, because I thought this was most
> similar to how we do fabric modules and so it was a ok fit.
> 

Oh shoot. Sorry. Forgot to cc the lio list on the first set of ceph/rbd
patches which this patchset is built on. They are here:

http://thread.gmane.org/gmane.comp.file-systems.ceph.devel/24553