Re: linux-2.4.18-modified-scsi-h.patch

[Andre Hedrick]

On Tue, 19 Nov 2002, Jeff Garzik wrote:

> Andre Hedrick wrote:
> 
> > Greetings Doug et al.
> >
> > Please consider the addition of this simple void ptr to the scsi_request
> > struct.  The addition of this simple void pointer allows one to map any
> > and all request execution caller the facility to search for a specific
> > operation without having to run in circles.  Hunting for these details
> > over the global device list of all HBA's is silly and one of the key
> > reasons why there error recovery path is so painful.
> >
> >
> > Scsi_Request    *req = sc_cmd->sc_request;
> > blah_blah_t     *trace = NULL;
> >
> > trace = (blah_blah_t *)req->trace_ptr;
> >
> >
> > Therefore the specific transport invoking operations via the midlayer will
> > have the ablity to track and trace any operation.
> >
> > It will save everyone headaches.
> >
> > Cheers,
> >
> >
> > Andre Hedrick, CTO & Founder
> > iSCSI Software Solutions Provider
> > http://www.PyXTechnologies.com/
> >
> >
> > ------------------------------------------------------------------------
> >
> > --- linux/drivers/scsi/scsi.h.orig	2002-10-31 01:45:39.000000000 -0800
> > +++ linux/drivers/scsi/scsi.h	2002-10-31 01:46:31.000000000 -0800
> > @@ -667,8 +667,11 @@
> >  	unsigned short sr_sglist_len;	/* size of malloc'd scatter-gather list */
> >  	unsigned sr_underflow;	/* Return error if less than
> >  				   this amount is transferred */
> > +	void *trace_ptr;	/* capable of cmd-cmnd-error tracing */
> 
> 
> ok
> 
> 
> >  };
> >
> > +#define MODIFIED_SCSI_H
> 
> 
> This falls into C style :)  Instead of this I would do
> 
> 	#define HAVE_TRACE_PTR 1
> 
> just like we already do HAVE_xxx in include/linux/netdevice.h and other 
> places.
> 
> 	Jeff

Works for me, just need to test the state of intelligence of the SCSI
stack and if it is possible to teach the old dog a new trick.  The ablitly
to logically seek an operation without chasing, the link list of devices
and outstanding commands, it tail!

Cheers,

Andre Hedrick, CTO & Founder 
iSCSI Software Solutions Provider
http://www.PyXTechnologies.com/