Jens Axboe wrote:
> On Mon, Sep 01 2008, Alasdair G Kergon wrote:
>> On Mon, Sep 01, 2008 at 05:15:58AM -0400, Valdis.Kletnieks@vt.edu wrote:
>>> On Mon, 01 Sep 2008 09:58:40 +0200, Tejun Heo said:
>>>> Yeah, I made a mistake converting two of them and devt lookup fails when
>>>> the disk is zero sized.  Bartlomiej debugged the problem and posted a
>>>> patch and I followed up with an updated patch.  It should be fine in the
>>>> next round.
>>>>   http://article.gmane.org/gmane.linux.kernel.next/2663
>>>>   http://article.gmane.org/gmane.linux.kernel.next/2676
>>>> If you're seeing other problems, please let me know.
>>> Confirming - 2.6.27-rc5-mmotm0829 plus the merge of the 2 above patches
>>> does find the LVM volumes and come up.  Thanks for the clue.. :)
>> I expect we'll need some patches to userspace lvm2 to support these extended
>> device numbers properly too...
>>
>> Alasdair (back from holiday)
> 
> They'll be defaulting to off from now on, so it should not be a big
> worry. But Alan Brunelle did find that the "10-character limit
> in dm/lib/libdm-deptree is too small".
> 

Tejun pointed out:

"dev_t is 32bits and MINORBITS is 20.  So, major 12 bits, minor 20
bits, so 4 characters for major, 7 characters for minor."

That would mean: 4+':'+7+'\0' = 13 characters at a minimum, so attached
patch seems to work...