bug#18329: mkpart clearing GPT attributes

[Brian C. Lane]

On Mon, Aug 25, 2014 at 01:52:07PM -0400, Scott Sullivan wrote:
> Parted version: 3.1.6-e38d-dirty
> 
> Summary: mkpart appears to be wiping out existing GPT attributes.
> 
> To reproduce, consider the below example of me reproducing this issue. It 
> doesn't seem like Parted should be clearing out existing GPT attributes for 
> other pre-existing partitions just by creating a new partition with mkpart.
> 
>  address@hidden /opt/template-automation/distros]# lvcreate -L 10G -n test LVM
>   Logical volume "test" created
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s 
> mklabel gpt
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s p 
> free
> Model: Linux device-mapper (linear) (dm)
> Disk /dev/dm-38: 10.7GB
> Sector size (logical/physical): 512B/512B
> Partition Table: gpt
> Disk Flags:
> 
> Number  Start   End     Size    File system  Name  Flags
>         17.4kB  10.7GB  10.7GB  Free Space
> 
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s 
> mkpart lbah 0% 10%
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s 
> mkpart lbah 10% 20%
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s p 
> free
> Model: Linux device-mapper (linear) (dm)
> Disk /dev/dm-38: 10.7GB
> Sector size (logical/physical): 512B/512B
> Partition Table: gpt
> Disk Flags:
> 
> Number  Start   End     Size    File system  Name  Flags
>         17.4kB  1049kB  1031kB  Free Space
>  1      1049kB  1074MB  1073MB               lbah
>  2      1074MB  2147MB  1074MB               lbah
>         2147MB  10.7GB  8590MB  Free Space
> 
> address@hidden /opt/template-automation/distros]# sgdisk -A 2:set:63 
> /dev/LVM/test
> Warning: The kernel is still using the old partition table.
> The new table will be used at the next reboot.
> The operation has completed successfully.
> address@hidden /opt/template-automation/distros]# sgdisk /dev/LVM/test 
> --attributes=2:show
> 2:63:1 (do not automount)
> address@hidden /opt/template-automation/distros]# parted /dev/LVM/test -s 
> mkpart lbah 20% 100%
> address@hidden /opt/template-automation/distros]# sgdisk /dev/LVM/test 
> --attributes=2:show
> address@hidden /opt/template-automation/distros]#
> 
> 
> Can someone confirm this isn't expected behavior? I am happy to help with 
> testing, on latest stable (3.2) or latest master if its useful. Our 
> workaround for now is to globally re-apply the GPT attributes after creating 
> all partitions.

Sadly, yes, this is how it currently works. I am surprised to see that
parted only tracks bit 0 and bit 2. The problem is that when it reads
the partition table it only copies the state of the bits it knows about
instead of making a copy of all of them.

-- 
Brian C. Lane | Anaconda Team | IRC: bcl #anaconda | Port Orchard, WA (PST8PDT)