tree 1b642880bf42f0943ae9533b1fa78f933022b183
parent 13c91cb7e28b47f5c4227f7e88a1378570117704
author Fam Zheng <famz@redhat.com> 1377220486 +0800
committer Stefan Hajnoczi <stefanha@redhat.com> 1378473908 +0200

block: implement reference count for BlockDriverState

Introduce bdrv_ref/bdrv_unref to manage the lifecycle of
BlockDriverState. They are unused for now but will used to replace
bdrv_delete() later.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>