This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


[Xen-devel] Re: [PATCH] xen_disk: treat "aio" as "raw"

On Thu, 30 Jun 2011, Alexander Graf wrote:
> On 06/30/2011 02:47 PM, Kevin Wolf wrote:
> > Am 30.06.2011 13:47, schrieb Alexander Graf:
> >> On 06/24/2011 04:50 PM, stefano.stabellini@xxxxxxxxxxxxx wrote:
> >>> From: Stefano Stabellini<stefano.stabellini@xxxxxxxxxxxxx>
> >>>
> >>> Sometimes the toolstack uses "aio" without an additional format
> >>> identifier, in such cases use "raw".
> >> Shouldn't this rather be a patch to the toolstack then? We do automatic
> >> file format recognition as default. I find magical "aio equals raw"
> >> subtleties rather unintuitive.
> > The asynchronous raw blktap driver is (was?) called "aio", so I guess
> > it's to stay compatible with that. Has always been this way in Xen (and
> > has always been confusing). As long as it stays in xen_disk.c, I don't
> > really mind...
> Is there a realistic chance of changing the toolstack here? I'd really 
> prefer not to drag this legacy around :).

We could change the toolstack but it would mean introducing an
incompatibility between the qdisk backend and the blktap backend.
Considering that qdisk was written to replace blktap in the first place
I don't think is such a good idea. Besides all xen toolstacks have
always written "aio" for "raw" even before qdisk came along...

Xen-devel mailing list