Re: [Qemu-devel] [PATCH 11/16] block/parallels: add support for backing files

[Kevin Wolf]

Am 15.12.2014 um 09:27 hat Denis V. Lunev geschrieben:
> From: Roman Kagan <address@hidden>
> 
> Add backing file support to Parallels format driver.
> 
> That said, I think backing file operations should end up in the generic
> block layer, but that's a longer story...
> 
> Signed-off-by: Roman Kagan <address@hidden>
> Signed-off-by: Denis V. Lunev <address@hidden>
> CC: Jeff Cody <address@hidden>
> CC: Kevin Wolf <address@hidden>
> CC: Stefan Hajnoczi <address@hidden>

How are users supposed to make use of this? bs->backing_file isn't set
during parallels_open(), so you generally dont' get a backing file.

Users might manually add -drive backing=..., but is there really no
support for storing the backing file in the image format? If so, perhaps
it's better not to support backing files at all here.

Kevin