On Tue, 15 Jun 2010 10:13:48 pm Christoph Hellwig wrote: > If we want to support barriers with the cache=writethrough mode in qemu > we need to tell the block layer that we only need queue drains to > implement a barrier. Follow the model set by SCSI and IDE and assume > that there is no volatile write cache if the host doesn't advertize it. > While this might imply working barriers on old qemu versions or other > hypervisors that actually have a volatile write cache this is only a > cosmetic issue - these hypervisors don't guarantee any data integrity > with or without this patch, but with the patch we at least provide > data ordering. > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> Thanks, applied. Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html