On Thu, Oct 12, 2006 at 12:14:31PM +0200, Elad Efrat wrote:
> YAMAMOTO Takashi wrote:
> >>> it's better to distinguish them from normal specfs operations.
> >>> ie. another REQ_xxx, rather than using NULL/NODEV.
> >> Oh, in that case, I can revert the previous change; though you'll have
> >> to help a bit with that as I'm unfamiliar with them.
> > 
> > i'm not familiar with details of each drivers either...
> > let's ask authers. :)  it seems that ad@ wrore or ported many of them.
> 
> Ah. :) I already did, a while ago, and the impression I received was
> that what these "passthru" calls do is basically raw access to kernel
> memory and/or disk in some of the cases.

In some cases, I think they do.  Though I guess SCSI passthrough, for
instance, should always be associated with a device.

Thor