https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/infiniband/core/cma.c#n1832 /* * Wait for any active callback to finish. New callbacks will find * the id_priv state set to destroying and abort. */ mutex_lock(&id_priv->handler_mutex); mutex_unlock(&id_priv->handler_mutex); It does nothing between the lock, what 's the meaning of it?
