Re: [Qemu-devel] [PATCH 3/7] block: fix snapshot with QED format

[Kevin Wolf]

Am 05.04.2012 17:42, schrieb Paolo Bonzini:
> QED's opaque data includes a pointer back to the BlockDriverState.
> Creating a snapshot whose format is QED breaks the relationship when
> bdrv_append shuffles data between bs_new and bs_top.  To avoid this,
> add a "rebind" function that tells the driver about the new relationship
> between the BlockDriverState and its opaque.
> 
> The patch also adds rebind to VVFAT for completeness, even though it is
> not used with live snapshots.
> 
> Thanks to Stefan and Jeff for help reproducing and debugging this.
> 
> Cc: Stefan Hajnoczi <address@hidden>
> Cc: Jeff Cody <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>

These drivers should really have been written in a way that they pass bs
instead of s when they need bs. I know that fixing the drivers properly
is much more work than adding another API that shouldn't exist in the
first place, so I'll take this anyway, but I do dislike it.

Kevin