[v2,06/11] xen_disk: simplify blk_disconnect with refcnt
diff mbox

Message ID 1374054136-28741-7-git-send-email-famz@redhat.com
State New
Headers show

Commit Message

Fam Zheng July 17, 2013, 9:42 a.m. UTC
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(-)

Comments

Stefan Hajnoczi July 23, 2013, 9:50 a.m. UTC | #1
On Wed, Jul 17, 2013 at 05:42:11PM +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 247f32f..ae17acc 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_delete(blkdev->bs);
> -        }
> +        bdrv_detach_dev(blkdev->bs, blkdev);
>          blkdev->bs = NULL;
>      }
>      xen_be_unbind_evtchn(&blkdev->xendev);

This reminds me that bdrv_detach_dev() needs a comment documenting that
it decrements the refcount; bs may be deleted when the function returns
and must not be accessed anymore.

Patch
diff mbox

diff --git a/hw/block/xen_disk.c b/hw/block/xen_disk.c
index 247f32f..ae17acc 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_delete(blkdev->bs);
-        }
+        bdrv_detach_dev(blkdev->bs, blkdev);
         blkdev->bs = NULL;
     }
     xen_be_unbind_evtchn(&blkdev->xendev);