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Date: Tue, 12 Jan 2010 18:44:38 +0100
From: Christoph Hellwig <hch@lst.de>
Subject: Re: [Qemu-devel] [PATCH 1/2] block: flush backing_hd in the right
	place
Message-ID: <20100112174438.GA733@lst.de>
References: <20100112124923.GA19631@lst.de> <4B4CB47C.7090206@redhat.com>
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To: Kevin Wolf <kwolf@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>, qemu-devel@nongnu.org

On Tue, Jan 12, 2010 at 06:42:20PM +0100, Kevin Wolf wrote:
> > @@ -623,6 +623,12 @@ int bdrv_commit(BlockDriverState *bs)
> >      if (drv->bdrv_make_empty)
> >  	return drv->bdrv_make_empty(bs);
> >  
> > +    /*
> > +     * Make sure all data we wrote to the backing device is actually
> > +     * stable on disk.
> > +     */
> > +    if (bs->backing_hd)
> > +        bdrv_flush(bs->backing_hd);
> >      return 0;
> >  }
> 
> Format drivers with a bdrv_make_empty return before the flush, so it
> won't work for qcow1. Looks good otherwise.

Oh, okay.

> If it has done a bdrv_make_empty we might also want to flush bs?

Indeed.  I'll spin a new version.