On Mon, Aug 02, 2010 at 02:38:18PM +0400, Vladislav Bolkhovitin wrote: > > Umm, I don't understand you. I think that fsync in particular is an > >example where you have to wait and issue cache flush if the drive has > >volatile write cache. Otherwise you cannot promise to the user data will be > >really on disk in case of crash. So no ordering helps you. > > Isn't there the second wait for journal update? Yes. > A drive can reorder queued SIMPLE requests at any time doesn't matter if > it has volatile write caches or not. I know. > So, if you expect in-order requests > execution (with journal updates you do?), you need to enforce that order > either by ORDERED requests or (local) queue draining. Yes, exactly what I say. -- 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
