Hello,

I've run into a situation where I need to export driver-hidden
information to sysfs.  This information is specific to a transport
(e.g., Parallel SCSI or Fiber Channel) and, in general, the kernel
doesn't use this information so it is not available outside the HBA
driver.

Attached is a patch that attempts to provide a means to export this
information to sysfs.  It introduces a new class for the scsi_device's
transport and provides facilities to export class_device_attributes.

A few suggestions that James Bottomley has already given are below, but
I thought that it was time that others saw this and could give their
suggestions too.  Thanks.

mh.


James' suggestions:

- Separate the transports out into two separate .c files (so they can be
loaded as modules).  This also plays in to future work I'm thinking
about: make the error handler more transport specific.
- Then, the class register/unregister can be done in the
module_init/exit routines
- Probably move all the show/store routines in .h files so they can be
used equally for fc and parallel
- This switch on ttype (and the enum transport_type) in
scsi_add_transport_attributes is not scaleable.  I think a better
solution might be to have a struct scsi_transport which has the class
device and a pointer to the overridden attribute.  Then, this is the
thing pointed to in the scsi host structure (and it can contain the
attributes, the class and a pointer to the default attributes, so most
of the trying to find the defaults code goes away).


-- 
Martin Hicks                Wild Open Source Inc.
mort@wildopensource.com     613-266-2296