Just a reminder
Below patch is also needed.
http://thread.gmane.org/gmane.comp.file-systems.ext4/19659
> Subject: RE: [Xen-devel] RE: Window VM hit blue screen when dom0 uses ext4 with extent enabled
> From: Ian.Campbell@xxxxxxxxxxxxx
> To: tinnycloud@xxxxxxxxxxx
> CC: xen-devel@xxxxxxxxxxxxxxxxxxx; jeremy@xxxxxxxx; konrad.wilk@xxxxxxxxxx
> Date: Thu, 14 Jul 2011 10:14:22 +0100
>
> On Thu, 2011-07-14 at 09:41 +0100, MaoXiaoyun wrote:
> >
> >
> > > Subject: Re: [Xen-devel] RE: Window VM hit blue screen when dom0
> > uses ext4 with extent enabled
> > > From: Ian.Campbell@xxxxxxxxxx
> > > To: tinnycloud@xxxxxxxxxxx
> > > CC: xen-devel@xxxxxxxxxxxxxxxxxxx; jeremy@xxxxxxxx;
> > konrad.wilk@xxxxxxxxxx
> > > Date: Thu, 14 Jul 2011 09:02:06 +0100
> > >
> > > On Thu, 2011-07-14 at 06:44 +0100, MaoXiaoyun wrote:
> > > > I think the 2.6.32.36 ext4 needs to backport this patch much
> > likely.
> > > > Otherwise it will hit the problem I met.
> > > >
> > > > http://patchwork.ozlabs.org/patch/79880/
> > >
> > > That version is still in state NEW but something appears to have
> > been
> > > committed upstream as e9e3bcecf44c04b9e6b505fd8e2eb9cea58fb94d:
> > >
> > > ext4: serialize unaligned asynchronous DIO
> > >
> > > ext4 has a data corruption case when doing non-block-aligned
> > > asynchronous direct IO into a sparse file, as demonstrated
> > > by xfstest 240.
> > >
> > > ...
> > >
> > > Seems like a reasonable enough thing to backport to me (for what
> > that's
> > > worth). Although:
> > > It is also quite a lot slower
> > > (14 min for package installs, vs. 8 min for well-aligned)
> > > but I'll take slow correctness over fast corruption any day.
> > >
> > > Mingming suggested that we can track outstanding
> > > conversions, and wait on those so that non-sparse
> > > files won't be affected, and I've implemented that here;
> > > unaligned AIO to nonsparse files won't take a perf hit.
> > >
> > > Something to bear in mind if you are deploying anything based on
> > sparse
> > > files on ext4.
> > >
> > That's right. Since we use VHD as our base image.
> > We are trying to backport this patch, but isn't easy for me.
> > Meanwhile, there are quite a lot ext4 patches in upstream, I'm afried
> > some of them are also needed for stable ext4, well, not sure.
> >
> > Could someone kindly backport e9e3bcecf44c04b9e6b505fd8e2eb9cea58fb94d
> > for me?
>
> I think would be a good idea to ping the ext4 developers about this and
> suggest that this might be a candidate for an upstream stable backport.
> If not then it would be good to know why not instead of blindly taking
> it into our stable tree...
>
> Ian.
>
> >
> > Many thanks.
> >
> > > Ian.
> > >
> > >
> > >
> >
>
>
