Bug#736173: lvextend segfault - narrowing it down

[Mike Bird]

Version: 2.02.95-8

No errors from badblocks, pvck, vgck, lvck, fsck.

I have to use -i1 and specify PV /dev/sdb6 as LVM wants to use
PV /dev/sda6 which doesn't have the 64 free extents I need.

However if I ask for only 1 extent the lvextend works with sda6
but still segfaults with sdb6.

Tried all alloc policies - no change.

Tried --noudevsync - no change.

Tried creating new empty /etc/lvm/{backup,archive} - no change.

The segfault occurs even with -t.

Here's the last part of -vvv output before the segfault.  The
"leaving 0" seems to be an unrelated logging error as it is also
shown when lvextend is successful


  Extending logical volume IMS+++ to 130.00 GiB
      Extending segment type, striped
        Allowing allocation on /dev/sda6 start PE 2048 length 683
        Trying allocation using contiguous policy.
        Still need 64 total extents:
          1 (1 data/0 parity) parallel areas of 64 extents each
          0 mirror logs of 0 extents each
        Considering allocation area 1 as /dev/sda6 start PE 2048 length 683 
leaving 0.
        Trying allocation using cling policy.
        Still need 64 total extents:
          1 (1 data/0 parity) parallel areas of 64 extents each
          0 mirror logs of 0 extents each
        Considering allocation area 1 as /dev/sda6 start PE 2048 length 683 
leaving 0.
        Trying allocation using normal policy.
        Cling_to_allocated is set
        Still need 64 total extents:
          1 (1 data/0 parity) parallel areas of 64 extents each
          0 mirror logs of 0 extents each
        Considering allocation area 1 as /dev/sda6 start PE 2048 length 683 
leaving 0.
Segmentation fault


If you need more info pls let me know.  Backuping up a giant LV, removing
it, creating a larger LV, and restoring is what LVM normally helps me avoid.