execute lvchange while mounting XFS filesystem

[ASANO Masahiro <masano@xxxxxxxxxxxxxx>]

Hi,

I encountered an oops and you can reproduce it with the following
operations:

  # lvcreate -L 32m -n masano1 /dev/vg0
  # mkfs.xfs /dev/vg0/masano1
  # mount /dev/vg0/masano1 /mnt/masano1
  # lvchange -p r /dev/vg0/masano1
  # touch /mnt/masano1/dummy
  # sync

I think that these operations may have no special meaning, however,
it seems that there is an issue in the error handling of writing
log operation.

I looked into XFS kernel sources but I could not find what led to this
oops. 

Thanks in advance,
--
masano