Re: [PATCH v3 3/3] init: add support for root devices specified by partition UUID

From: Will Drewry
Date: Thu Aug 05 2010 - 15:19:24 EST


On Thu, Aug 5, 2010 at 9:29 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:
> Hello,
>
> On 08/05/2010 04:26 PM, Will Drewry wrote:
>> On Thu, Aug 5, 2010 at 5:55 AM, Tejun Heo <tj@xxxxxxxxxx> wrote:
>>> Hello,
>>>
>>> On 08/04/2010 08:22 PM, Will Drewry wrote:
>>>> @@ -642,6 +642,7 @@ void __init printk_all_partitions(void)
>>>>               struct hd_struct *part;
>>>>               char name_buf[BDEVNAME_SIZE];
>>>>               char devt_buf[BDEVT_SIZE];
>>>> +             u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1];
>>>>
>>>>               /*
>>>>                * Don't show empty devices or things that have been
>>>> @@ -660,10 +661,14 @@ void __init printk_all_partitions(void)
>>>>               while ((part = disk_part_iter_next(&piter))) {
>>>>                       bool is_part0 = part == &disk->part0;
>>>>
>>>> -                     printk("%s%s %10llu %s", is_part0 ? "" : "  ",
>>>> +                     uuid[0] = 0;
>>>> +                     if (part->info)
>>>> +                             part_unpack_uuid(part->info->uuid, uuid);
>>>> +
>>>> +                     printk("%s%s %10llu %s %s", is_part0 ? "" : "  ",
>>>>                              bdevt_str(part_devt(part), devt_buf),
>>>>                              (unsigned long long)part->nr_sects >> 1,
>>>> -                            disk_name(disk, part->partno, name_buf));
>>>> +                            disk_name(disk, part->partno, name_buf), uuid);
>>>
>>> Hmmm... I'm a bit worried about this.  This might break userspace
>>> tools.  I think it would be better to export it via sysfs.
>>
>> Cool - I'm happy to drop that part from the patch.  I was more
>> following the spirit of the comment around making it easy for a user
>> to figure out what went wrong (e.g., wrong uuid) if they don't have a
>> root, but if there are tools parsing that output, I'd rather not break
>> them!
>
> Oh, forget about what I said.  For some reason I thought the above
> code was for /proc/partitions.  :-)

Cool - even better!

Thanks!
will
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