Re: NILFS2: double uuid

Ryusuke Konishi
2015-06-09T16:00:55Z

On Tue, 9 Jun 2015 16:07:42 +0200, Karel Zak <kzak@redhat.com> wrote:
> On Tue, Jun 09, 2015 at 10:04:15PM +0900, Ryusuke Konishi wrote:
>> $ sudo nilfs-resize -y /dev/sdb1 1G
>> Partition size = 2146435072 bytes.
>> Shrink the filesystem size from 2146435072 bytes to 1073741824 bytes.
>> 128 segments will be truncated from segnum 127.
>> Moving 103 in-use segments.
>> progress |***********************************************|
>> Done.
>>
>> $ sudo umount /test
>> $ sudo mount /dev/sdb1 /test
>> $ sudo LD_LIBRARY_PATH=/usr/local/lib lsblk -f
>> NAME FSTYPE LABEL UUID MOUNTPOINT
>> [...]
>> sdb
>> `-sdb1 /test
>>
>> This blank state continued until I shrank the partition or
>> re-extended the filesystem to the partition size.
>>
>> Could you consider confining the s_dev_size test only to the
>> backup superblock ?
>
> Hmm... why nilfs-resize does not update the size in the superblock?
> It seems like nilfs-resize bug.

nilfs-resize (to be exact, RESIZE ioctl of nilfs2) updates s_dev_size
in both superblocks. What nilfs-resize doesn't change is the
partition size. (It needs help of a partitioning tool)

>
>> It seems that we don't have to drop the primary super block
>> even if s_dev_size doesn't fit to the partition size.
>
> Yes, fixed. I have also enabled the s_dev_size check for whole-disk
> devices only to minimize number of situations when we rely on the
> s_dev_size.
>
> Karel

Thanks again. The updated libblkid/lsblk works frawlessly.

Regards,
Ryusuke Konishi