Re: [Qemu-devel] [PATCH v3] block: Close backing file early in bdrv_img_create

[Stefan Hajnoczi <stefanha@gmail.com>]

On Tue, Dec 03, 2013 at 02:57:52PM +0100, Max Reitz wrote:
> Leaving the backing file open although it is not needed anymore can
> cause problems if it is opened through a block driver which allows
> exclusive access only and if the create function of the block driver
> used for the top image (the one being created) tries to close and reopen
> the image file (which will include opening the backing file a second
> time).
> 
> In particular, this will happen with a backing file opened through
> qemu-nbd and using qcow2 as the top image file format (which reopens the
> image to flush it to disk).
> 
> In addition, the BlockDriverState in bdrv_img_create() is used for the
> backing file only; it should therefore be made local to the respective
> block.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> ---
> v3:
>  - Reverted the revert in v2 and limited the BlockDriverState once again
>    to the scope its used in (addressing Xia's comment); added a missing
>    bdrv_unref() in contrast to v1 (addressing Kevin's comment to v1)
> 
> v2:
>  - Minimizing the changes prevents introducing a leak of the
>    BlockDriverState in case of an error in bdrv_open() (thanks, Kevin).
> ---
>  block.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

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

Stefan