Re: [Qemu-devel] [PATCH] block: Update image size in bdrv_invalidate_cache()

[Stefan Hajnoczi <stefanha@gmail.com>]

On Tue, Mar 11, 2014 at 10:58:39AM +0100, Kevin Wolf wrote:
> After migration has completed, we call bdrv_invalidate_cache() so that
> drivers which cache some data drop their stale copy of the data and
> reread it from the image file to get a new version of data that the
> source modified while the migration was running.
> 
> Reloading metadata from the image file is useless, though, if the size
> of the image file stays stale (this is a value that is cached for all
> image formats in block.c). Reads from (meta)data after the old EOF
> return only zeroes, causing image corruption.
> 
> We need to update bs->total_sectors in all layers that could potentially
> have changed their size (i.e. backing files are not a concern - if they
> are changed, we're in bigger trouble)
> 
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>  block.c       | 10 +++++++++-
>  block/qcow2.c |  2 ++
>  block/qed.c   |  3 +++
>  3 files changed, 14 insertions(+), 1 deletion(-)

Thanks, applied to my block tree:
https://github.com/stefanha/qemu/commits/block

Stefan