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Date: Fri, 3 Jan 2014 18:04:09 +0800
From: Stefan Hajnoczi <stefanha@gmail.com>
Message-ID: <20140103100409.GD1483@stefanha-thinkpad.redhat.com>
References: <1386920120-2651-1-git-send-email-famz@redhat.com>
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In-Reply-To: <1386920120-2651-10-git-send-email-famz@redhat.com>
Subject: Re: [Qemu-devel] [PATCH v8 09/12] block: Support dropping active in
 bdrv_drop_intermediate
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To: Fam Zheng <famz@redhat.com>
Cc: kwolf@redhat.com, rjones@redhat.com, armbru@redhat.com, qemu-devel@nongnu.org, imain@redhat.com, stefanha@redhat.com, pbonzini@redhat.com

On Fri, Dec 13, 2013 at 03:35:17PM +0800, Fam Zheng wrote:
> + * 1) This will convert the following chain:
> + * ... <- base <- ... <- top <- overlay <-... <- active
> + *
> + * to
>   *
> - * Requires that the overlay to 'top' is opened r/w, so that the backing file
> - * information in 'bs' can be properly updated.
> + * ... <- base <- overlay <- active
>   *
> - * E.g., this will convert the following chain:
> - * bottom <- base <- intermediate <- top <- active
> + * 2) It is allowed for bottom==base, in which case it converts:
> + *
> + * ... <- base <- ... <- top <- overlay <- ... <- active

If bottom==base then I think it should be:

base <- ... <- top <- overlay <- ... <- active

(Dropping the "... <- " prefix)