Why hp io accelerator [3rd party module] fails to build on RHEL6.1 ?

Issue

• hp io accelerator SRPM fails to build kernel module on RHEL6.1 but builds fine on RHEL6.0

  STDOUT:   CC [M]  /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source/kblock.o
  STDOUT: make[1]: Leaving directory `/usr/src/kernels/2.6.32-131.0.15.el6.x86_64'
  STDOUT: make: Leaving directory `/tmp/selfgz2351823870/hp_io_accelerator-
  2.2.3.66.52-rhel-6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source'
  STDOUT: 
  STDOUT: 
  STDOUT: RPM build errors:
  STDERR: + umask 022
  STDERR: + cd /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD
  STDERR: + cd /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD
  STDERR: + rm -rf iomemory-vsl-2.2.3.66
  STDERR: + /usr/bin/gzip -dc /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-
  rhel-6/build/SOURCES/iomemory-vsl-2.2.3.66.tar.gz
  STDERR: + /bin/tar -xf -
  STDERR: + STATUS=0
  STDERR: + '[' 0 -ne 0 ']'
  STDERR: + cd iomemory-vsl-2.2.3.66
  STDERR: + /bin/chmod -Rf a+rX,u+w,g-w,o-w .
  STDERR: + exit 0
  STDERR: + umask 022
  STDERR: + cd /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD
  STDERR: + cd iomemory-vsl-2.2.3.66
  STDERR: + rsync -rv root/usr/src/iomemory-vsl/ driver_source/
  STDERR: + /usr/bin/make -C driver_source KERNELVER=2.6.32-131.0.15.el6.x86_64 
  FIO_DRIVER_NAME=iomemory-vsl modules
  STDERR: /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source/kblock.c: In function 
  'kfio_handle_special_req':
  STDERR: /tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source/kblock.c:402: error: implicit 
  declaration of function 'blk_barrier_rq'
  STDERR: make[2]: *** [/tmp/selfgz2351823870/hp_io_accelerator-2.2.3.66.52-rhel-
  6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source/kblock.o] Error 1
  STDERR: make[1]: *** [_module_/tmp/selfgz2351823870/hp_io_accelerator-
  2.2.3.66.52-rhel-6/build/BUILD/iomemory-vsl-2.2.3.66/driver_source] Error 2
  STDERR: make: *** [modules] Error 2
  STDERR: + set +x
  STDERR: ERROR:
  STDERR: 
  STDERR: error: Bad exit status from /tmp/selfgz2351823870/hp_io_accelerator-
  2.2.3.66.52-rhel-6/build/tmp/rpm-tmp.RpsMpi (%build)
  STDERR:     Bad exit status from /tmp/selfgz2351823870/hp_io_accelerator-
  2.2.3.66.52-rhel-6/build/tmp/rpm-tmp.RpsMpi (%build)