Re: [Qemu-devel] [PATCH 7/8] xen_disk: simplify blk_disconnect with refcnt

[Jeff Cody <jcody@redhat.com>]

On Thu, Jul 25, 2013 at 05:01:45PM +0800, Fam Zheng wrote:
> We call bdrv_attach_dev when initializing whether or not bs is created
> locally, so call bdrv_detach_dev and let the refcnt handle the
> lifecycle.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  hw/block/xen_disk.c | 7 +------
>  1 file changed, 1 insertion(+), 6 deletions(-)
> 
> diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
> index 99537e8..3ec4bd2 100644
> --- a/hw/block/xen_disk.c
> +++ b/hw/block/xen_disk.c
> @@ -910,12 +910,7 @@ static void blk_disconnect(struct XenDevice *xendev)
>      struct XenBlkDev *blkdev = container_of(xendev, struct XenBlkDev, xendev);
>  
>      if (blkdev->bs) {
> -        if (!blkdev->dinfo) {
> -            /* close/delete only if we created it ourself */
> -            bdrv_close(blkdev->bs);
> -            bdrv_detach_dev(blkdev->bs, blkdev);
> -            bdrv_unref(blkdev->bs);
> -        }
> +        bdrv_detach_dev(blkdev->bs, blkdev);
>          blkdev->bs = NULL;

If the refcnt for blkdev->bs is > 1, then this leaks blkdev->bs, and
doesn't call bdrv_close().

>      }
>      xen_be_unbind_evtchn(&blkdev->xendev);
> -- 
> 1.8.3.2
> 
>