Userspace tools assume if a value is read from configfs, it is valid
and will not cause an error if the same value is written back. The only
valid value for pi_prot_type for backends not supporting DIF is 0, so allow
this particular value to be set without returning an error.
Reported-by: NKrzysztof Chojnowski <frirajder@gmail.com>
Signed-off-by: NAndy Grover <agrover@redhat.com>
Reviewed-by: NSagi Grimberg <sagig@mellanox.com>
Cc: stable@vger.kernel.org # 3.14+
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>