Re: [patch] convert the scsi layer to use struct device

James Bottomley
2008-03-15T18:31:25Z

On Sat, 2008-03-15 at 19:04 +0100, Kay Sievers wrote:
> On Sat, 2008-03-15 at 11:16 -0500, James Bottomley wrote:
> > > We just need to create something like a "contains" link from the
> > > component to the scsi device, and a "enclosure" link at the scsi device
> > > back to the component, right?
> >
> > Assuming you're moving to the single tree model, then I can easily do
> > this:
> >
> > <real enclosure device>/<enclosure>/<enclosure component>/device -> link
> > to component device
>
> Yes, sounds good. Only that there will be no meaningful "device" link
> with !SYSFS_DEPRECATED, we need a custom link, maintained by the
> enclosure itself, to do that.
>
> > with a back link in the component device pointing to the enclosure
> > component.
>
> That sounds fine.
>
> > The way components work, probably blowing away enclosure_component_class
> > makes the most sense anyway.
>
> If we go for a single class, can't we express enclosures and components
> in the device name and put them in the same class like:
> /sys/class/enclosure/
> |- enclosure1 -> ../../../devices/<...>/enclosure1
> |- enclosure1.slot1 -> ../../../../devices/<...>/enclosure1/enclosure1.slot1
> |- enclosure1.slot2 -> ../../../../devices/<...>/enclosure1/enclosure1.slot2
> |- enclosure2 -> ﻿../../../devices/<...>/enclosure2
> |- enclosure2.slot1 -> ﻿-> ../../../../devices/<...>/enclosure1/enclosure2.slot1
> ...
>
> while /sys/devices/<...>/enclosure1/enclosure1.slot1/ has a something
> like a "contains" link pointing to the SCSI device, and the SCSI device
> an "enclosure" link back?

OK, I've got a two expander system with six slots each pretending to be
a twelve slot installation. I've also got two slots populated (slot 1
and 6). This is what it looks like with the deprecated setting:

sparkweed:/sys/class/enclosure# tree
.
|-- 0:0:1:0
| |-- SLOT 006
| | |-- active
| | |-- device -> ../../../../devices/pci0000:01/0000:01:02.0/host0/port-0:0/expander-0:0/port-0:0:0/end_device-0:0:0/target0:0:0/0:0:0:0
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- SLOT 007
| | |-- active
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- SLOT 008
| | |-- active
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- SLOT 009
| | |-- active
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- SLOT 010
| | |-- active
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- SLOT 011
| | |-- active
| | |-- fault
| | |-- locate
| | |-- power
| | | `-- wakeup
| | |-- status
| | |-- type
| | `-- uevent
| |-- components
| |-- device -> ../../../devices/pci0000:01/0000:01:02.0/host0/port-0:0/expander-0:0/port-0:0:12/end_device-0:0:12/target0:0:1/0:0:1:0
| |-- power
| | `-- wakeup
| |-- subsystem -> ../../enclosure
| `-- uevent
`-- 0:0:3:0
|-- SLOT 000
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 001
| |-- active
| |-- device -> ../../../../devices/pci0000:01/0000:01:02.0/host0/port-0:1/expander-0:1/port-0:1:11/end_device-0:1:11/target0:0:2/0:0:2:0
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 002
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 003
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 004
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 005
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- components
|-- device -> ../../../devices/pci0000:01/0000:01:02.0/host0/port-0:1/expander-0:1/port-0:1:12/end_device-0:1:12/target0:0:3/0:0:3:0
|-- power
| `-- wakeup
|-- subsystem -> ../../enclosure
`-- uevent

And without the deprecated setting:

sparkweed:/sys/class/enclosure# tree
.
|-- 0:0:1:0 -> ../../devices/pci0000:01/0000:01:02.0/host0/port-0:0/expander-0:0/port-0:0:12/end_device-0:0:12/target0:0:1/0:0:1:0/enclosure/0:0:1:0
`-- 0:0:3:0 -> ../../devices/pci0000:01/0000:01:02.0/host0/port-0:1/expander-0:1/port-0:1:12/end_device-0:1:12/target0:0:3/0:0:3:0/enclosure/0:0:3:0

sparkweed:/sys/class/enclosure/0:0:1:0# tree
.
|-- SLOT 006
| |-- active
| |-- device -> ../../../../../../../port-0:0:0/end_device-0:0:0/target0:0:0/0:0:0:0
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 007
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 008
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 009
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 010
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- SLOT 011
| |-- active
| |-- fault
| |-- locate
| |-- power
| | `-- wakeup
| |-- status
| |-- type
| `-- uevent
|-- components
|-- device -> ../../../0:0:1:0
|-- power
| `-- wakeup
|-- subsystem -> ../../../../../../../../../../../../class/enclosure
`-- uevent

So are we now all happy?

James

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