The lock is designed to protect internal state of zvol_state_t and
to avoid taking spa_namespace_lock (e.g. in dmu_objset_own() code path)
while holding zvol_stat_lock. Refactor the code accordingly.
Signed-off-by: Boris Protopopov <boris.protopopov@actifio.com>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes#3484Closes#6065Closes#6134
5559ba094f