Bug#561931: LVM Extend Segfault on RAID PVs

[Ian MacDonald]

The same version of lvm2 is used in Ubuntu Karmic, and exhibits similar
behaviour.  My system is running 2.6.31-20-generic #57-Ubuntu SMP AMD64
(current karmic-proposed).  

Ubuntu bug is filed here, however I suspect this is the same issue.

https://bugs.launchpad.net/ubuntu/+source/lvm2/+bug/530240 

Below is the series of commands executed on my logical volumes, two of
them currently open were extended 20GB (prior to file system resize),
and then I wanted to consume the remaining extends on one of them.

Prior to executing these commands I removed two other existing volumes
in the same group in order to free up the space.

My pv's sit on top of a RAID1 md device as shown below, similar to the
original report. 

>From dpkg:

ii lvm2                                            2.02.39-0ubuntu11 

>From dmesg:

[13442.816905] lvextend[6576]: segfault at 0 ip 00000000004564eb sp
00007fff6dbc1a60 error 4 in lvm[400000+8e000]

>From console:
root at laptop:/mnt# lvs
  LV   VG   Attr   LSize  Origin Snap%  Move Log Copy%  Convert
  home raid -wi-ao 20.00G                                      
  virt raid -wi-ao 20.00G                                      

root at laptop:/mnt# pvs
  PV         VG   Fmt  Attr PSize  PFree 
  /dev/md1   raid lvm2 a-   82.02G 42.02G

root at laptop:/mnt# lvextend -L +20G /dev/raid/home 
  Extending logical volume home to 40.00 GB
  Logical volume home successfully resized

root at laptop:/mnt# lvextend -L +20G /dev/raid/virt 
  Extending logical volume virt to 40.00 GB
  Logical volume virt successfully resized

root at laptop:/mnt# pvs
  PV         VG   Fmt  Attr PSize  PFree
  /dev/md1   raid lvm2 a-   82.02G 2.02G

root at laptop:/mnt# lvs
  LV   VG   Attr   LSize  Origin Snap%  Move Log Copy%  Convert
  home raid -wi-ao 40.00G                                      
  virt raid -wi-ao 40.00G                    

root at laptop:/mnt# pvs
  PV         VG   Fmt  Attr PSize  PFree
  /dev/md1   raid lvm2 a-   82.02G 2.02G

root at laptop:/mnt# lvextend -l +100%PVS /dev/raid/home 
Segmentation fault