Re: [PATCH v3 3/3] init: add support for root devices specified by partition UUID
From: Will Drewry
Date: Thu Aug 05 2010 - 10:26:43 EST
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!
Would sysfs make sense as part of this patch series or would it be
fair game for a follow-on? I'm inclined to wait since the UUIDs can't
be changed (blkpg support isn't wired up) except with rescans, and a
userspace tool can just walk the partition table to get the uuids.
Thanks!
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