Checking uniqueness of portal group is done without mutex and
before register/unregister. This is not thread-safe.
Hence this patch is added to ensure PG uniqueness.
A little related refactoring is also done.
Change-Id: Iaa3b5e380f2be5cfdaa2d69f9f2763c98954b0c3
Signed-off-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-on: https://review.gerrithub.io/396847
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>