Re: RFC: SCSI Generic version 4 interface

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, Nov 07 2006, Jeff Garzik wrote:
> Douglas Gilbert wrote:
> >I was asked to put together a proposal in May this
> >year for a new SCSI Generic interface structure. This
> >is the same structure that is used by the block layer
> >SG_IO ioctl. A few people have asked whether I had forgotten
> >that I agreed to write the proposal. So here it is. Those
> >who have seen it have made comments, some of which have
> >been incorporated.
> >
> >Some shortcomings of the sg version 3 interface are:
> >  - can't handle commands with bidirectional data (either
> >    can the SCSI subsystem at the moment)
> >  - if it was a bit more general it could carry other
> >    request/response protocols (e.g. Task Management
> >    Functions and SMP in Serial Attached SCSI)
> >  - no way of associating a task attribute or task tag
> >    with a SCSI command
> 
> Why avoid Jens Axboe's bsg?
> 
> It seems like that is already a good interface for carrying other 
> req/resp protocols.

I don't think Doug is avoiding that (if you are Doug, please do explain
:-), but rather outlining the next generation command format that bsg
should support for future use.

-- 
Jens Axboe