Re: [PATCH 1/1] cciss: resubmit export uid, model, vendor, rev to sysfs

[Kay Sievers]

On Wed, Apr 8, 2009 at 09:24, Andrew Patterson <andrew.patterson@xxxxxx> wrote:
> On Wed, 2009-04-08 at 05:26 -0700, Kay Sievers wrote:
>> On Tue, Apr 7, 2009 at 23:19, Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
>> > On Tue, Apr 07 2009, Mike Miller (OS Dev) wrote:
>>
>> > The patch looks fine to me, but my sysfs foo is very weak though. CC'ing
>> > Kay, perhaps he can help take a quick look at this.
>>
>> >> + * Initialize sysfs for each logical drive. ÂThis sets up and registers
>> >> + * the 'c#d#' directory for each individual logical drive under
>> >> + * /sys/bus/pci/devices/<dev/ccis#/. We also create a link from
>> >> + * /sys/block/cciss!c#d# to this entry.
>> >> + */
>> >> +static int cciss_create_ld_sysfs_entry(struct ctlr_info *h,
>> >> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âdrive_info_struct *drv,
>> >> + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Âint drv_index)
>> >> +{
>> >> + Â Â device_initialize(&drv->dev);
>> >> + Â Â drv->dev.type = &cciss_dev_type;
>> >> + Â Â dev_set_name(&drv->dev, "c%dd%d", h->ctlr, drv_index);
>> >> + Â Â drv->dev.parent = &h->dev;
>> >> + Â Â return device_add(&drv->dev);
>> >> +}
>>
>> If I read that correctly, you are creating a hierarchy of devices
>> where the devices do not belong to any subsystem? This is what we need
>> to avoid in almost all cases, we need a "subsystem" link in sysfs.
>>
>
> Yes, but apparently mistakenly.
>
>> I wold expect the cciss devices not to be a magic, silently created,
>> subdirectory of a pci device, but to have their own "cciss" bus in
>> sysfs, so the created devices get proper events at creation time. All
>> the cciss devices would show up in its own directory
>> /sys/bus/cciss/devices/*.
>>
>> I think, you should name all "cciss bus devices" uniquely, and assign
>> them to a "cciss bus_type". We really do not want unclassified devices
>> in the chain of parent devices of a block device.
>>
>
> I'll try this. ÂAlthough I am wondering whether to put hosts or logical
> drives in /sys/bus/cciss/devices (or both). Can I do what I am doing
> now, just moving it to /sys/bus/cciss/devices? That
> is, /sys/bus/cciss/devices/ccissX/cYdZ.

Do what you have today, just make sure all your devices are uniquely
named, and assigned to the cciss bus_type. There can be no hierarchies
in /sys/bus/*/devices, there are only symlinks. The hierarchy is only
in /sys/devices/, and if I correctly look at what you have, you have
that already.

Kay
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