Re: [RFC/PATCH 0/2] support for CMS-formatted disks on the s/390 architecture

[Jim Meyering]

Stephen Powell wrote:
> On Sat, 17 Apr 2010 11:10:04 -0400 (EDT), Jim Meyering wrote:
>>
>> Thanks for preparing those.
>> Can either of you outline a test for each that would fail before
>> application of a patch and succeed after it?
>
> For the first problem, the invalid starting block for an LDL disk,
> the failure would involve reporting an incorrect starting position,
> an incorrect partition size, and not
> recognizing any file system which might be on it, since it is
> not pointing to the superblock.  This occurs only on LDL disks
> with a block size other than 4096.

Thanks.  Good overview of what's needed.
Can you give more detail?  For example, how would you create
an LDL disk with block size != 4096?

> With the patch, the partition size
> will be correct, the starting position will be correct,
> and it will recognize the file system built on the
> partition, if there is one.  The command would be something like
>
>    parted /dev/dasda print
>
> For the second problem, lack of recognition of CMS minidisks, the
> above command will report

Can you provide or tell how to construct a minimal example image?

My goal is to write a portable shell script that triggers
the flaw, and use that to show your fix solves the problem.

>    Error: /dev/dasda: unrecognised disk label
>
> if the patch is not on.  If the patch is on, it will generate the
> normal expected output for the above command.