Date: Wed, 10 Jun 2015 01:00:29 +0900 (JST)
Message-Id: <20150610.010029.2104807508136297204.konishi.ryusuke@lab.ntt.co.jp>
To: Karel Zak <kzak@redhat.com>
Cc: Heinz Diehl <htd+ml@fritha.org>, linux-kernel@vger.kernel.org,
        linux-nilfs@vger.kernel.org
Subject: Re: NILFS2: double uuid
From: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
In-Reply-To: <20150609140742.GH1992@ws.net.home>
References: <20150609085329.GF1992@ws.net.home>
	<5576E44F.5030201@lab.ntt.co.jp>
	<20150609140742.GH1992@ws.net.home>
Mime-Version: 1.0
Content-Type: Text/Plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1824
Lines: 50

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/