Messages in this thread |  | | Date | Tue, 1 May 2001 10:53:58 -0600 | From | Richard Gooch <> | Subject | Re: [PATCH] adding PCI bus information to SCSI layer |
| |
Ingo Oeser writes: > On Mon, Apr 30, 2001 at 07:27:13PM -0600, Richard Gooch wrote: > > Then, vendors provide their own PCI fixups, which turn /dev/bus/pci0 > > What about /dev/bus/pci/0 or /dev/bus/pci/pci0 instead? > > That way we could hook roots of busses (which are "." nodes, like > if they where mounted independently) better into /dev/bus.
I'm wary of this, because Linus has stated that the current "struct pci_dev" is really meant to be a generic thing, and it might change to "struct dev" (now that we've renamed the old "struct dev" to "struct netdev").
So, if the bus management code is maintaining some kind of unified tree, it might not make sense to have a /dev/bus/pci and /dev/bus/sbus.
> And even implement the thing as a mount point later, if we go the way > Al Viro suggested and have independent "device filesystems" > for the subsystems themselves.
As I understand it, Al want to turn every driver into a filesystem, instead of using an existing FS (devfs). I can't see the point. There certainly haven't been any technical benefits put forward for this idea.
I spoke to Linus about this, and he wants to leave the option open for some drivers to implement their own FS rather than calling into devfs. He cited iSCSI as a case where this might be useful (since you need to do something different for readdir() and lookup()). I'll be experimenting with iSCSI myself, and I'll try out a modification to devfs which allows a driver to register lookup() and readdir() methods when calling devfs_mk_dir(). If this can be done sanely, then it would provide an easier interface than using the VFS to implement a new FS. So this particular issue remains open.
However, it's my understanding that Linus isn't trying to push existing drivers, which work well with devfs, into implementing their own FS. He just wants the option left open for new drivers where a driver-specific FS makes more sense.
Regards,
Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
|  |