Re: [PATCH 1/2] SCSI: Add a SCSI option for persistent device names in Kernel.

Kay Sievers
2011-04-08T16:43:33Z

On Fri, Apr 8, 2011 at 18:14, Greg KH <greg@kroah.com> wrote:
> On Fri, Apr 08, 2011 at 08:14:12AM -0700, James Bottomley wrote:
>> So, while I agree totally with the above: udev and userspace is the way
>> to go, I'm not totally opposed to having a non-invasive mechanism for
>> indicating a user's preferred name for a device.  I think there are a
>> couple of ways to do this:
>>
>>      1. Entirely in userspace: just have udev consult a preferred name
>>         file and create say /dev/disk/by-preferred.  Then have all the
>>         tools that normally output device information do the same (i.e.
>>         since real name to preferred name is 1:1, they could all do a
>>         reverse lookup).
>>      2. have a writeable sysfs preferred_name field, either in the
>>         generic device or just in SCSI.  The preferred name would be
>>         used by outbound only (i.e. kernel dev_printk messages and
>>         possibly /proc/partitions).  All inbound uses of the device
>>         would come via the standard udev mechanisms
>>         (i.e. /dev/disk/by-preferred would be the usual symlink).  This
>>         means from the kernel point of view, no renaming has happened.
>>         We'd just try to print out the preferred name in certain
>>         circumstances, which should solve most of the described problem.
>
> Either, or both, of those options are fine with me as well.

I guess a generic sysfs file, that can carry a user-given name for a
device, and which is looked-up with dev_printk() macro, and maybe
/proc/partitions is all what we would need if we want to involve the
kernel here.

Kay