On Tue, Sep 04, 2012 at 03:45:57PM +0200, Paolo Bonzini wrote: > > Also - some kind of comment explaining why a similar race can not happen > > with this lock in place would be nice: I see why this specific race can > > not trigger but since lock is dropped later before you submit command, I > > have hard time convincing myself what exactly gurantees that vq is never > > switched before or even while command is submitted. > > Because tgt->reqs will never become zero (which is a necessary condition > for tgt->req_vq to change), as long as one request is executing > virtscsi_queuecommand. > > Paolo Yes but this logic would apparently imply the lock is not necessary, and it actually is. I am not saying anything is wrong just that it looks scary. -- MST -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html