Re: [PATCH] minimal SAS transport class

[Luben Tuikov <luben_tuikov@adaptec.com>]

On 08/26/05 15:24, Jeff Garzik wrote:
> Luben Tuikov wrote:
> 
>>Even simpler: the transport layer, calls SCSI Core, saying: "Hey here is
>>a pointer to struct scsi_domain_device.  If you want, you an send REPORT
>>LUNS and other things to it."
> 
> 
> For the SG_IO ioctl, /dev/sg and request_queue usage, SCSI core must map 
> an address (currently HCIL) into a scsi_domain_device pointer.  These 

The request queue is associated with the LU, not the scsi_domain_device.
When SCSI Core discovers the LU, it sets up the request queue for it,
etc.  Again this is the role of SCSI Core, not messing up with transport
specific stuff.

> upper layer kernel elements rely on this "SCSI address", and rely on the 
> fact that SCSI core can route from a block device straight to a SCSI 
> LLD, using nothing more than this "SCSI address."

I don't get this.

> That is the heart of the routing/addressing that the SCSI core must perform.

Disagree: now: scsi_device <--> request_queue, then: struct LU <--> request_queue.

The LU points to the domain_device (as its parent). The domain_device
has a void *lldd_dev in it.  

> Right now the addressing is hardcoded to HCIL.  But that can be 
> changed...  One proposal was to use (host,string) identifiers.

Who? Who is proposing this? I never saw an email to SCSI Core about
this proposal?  Is there any more information about this proposal
and what is the justification of it?  Any specs and docs?

	Luben